Citation
Water resources of Alachua, Bradford, Clay, and Union Counties, Florida ( FGS: Report of investigations 35 )

Material Information

Title:
Water resources of Alachua, Bradford, Clay, and Union Counties, Florida ( FGS: Report of investigations 35 )
Series Title:
( FGS: Report of investigations 35 )
Creator:
Clark, William E
Geological Survey (U.S.)
Place of Publication:
Tallahassee
Publisher:
[s.n.]
Publication Date:
Language:
English
Physical Description:
xi, 170 p. : illus., maps. (part fold.) diagra., tables. ; 23 cm.

Subjects

Subjects / Keywords:
Hydrology -- Florida ( lcsh )
Water-supply -- Florida ( lcsh )
Alachua County ( flgeo )
Clay County ( flgeo )
Lakes ( jstor )
Creeks ( jstor )
Water wells ( jstor )

Notes

General Note:
"Prepared by the United States Geological Survey in cooperation with the Florida Geological Survey, Tallahassee."
General Note:
"References": p. 166-170.
Statement of Responsibility:
by William E. Clark [and others]

Record Information

Source Institution:
University of Florida
Rights Management:
The author dedicated the work to the public domain by waiving all of his or her rights to the work worldwide under copyright law and all related or neighboring legal rights he or she had in the work, to the extent allowable by law.
Resource Identifier:
022567383 ( ALEPH )
01745680 ( OCLC )
AAQ2420 ( NOTIS )
a 65007006 ( LCCN )

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Full Text
STATE OF FLORIDA
STATE BOARD OF CONSERVATION
DIVISION OF GEOLOGY
FLORIDA GEOLOGICAL SURVEY
Robert O. Vernon, Director
REPORT OF INVESTIGATIONS NO. 35
WATER RESOURCES OF
ALACHUA, BRADFORD, CLAY, AND UNION
COUNTIES, FLORIDA
By
WILLIAM E. CLARK, RUFUS H. MUSGROVE,
CLARENCE G. MENKE, AND JOSEPH W. CAGLE, JR.
Prepared by the
UNITED STATES GEOLOGICAL SURVEY
in cooperation with the
FLORIDA GEOLOGICAL SURVEY TALLAHASSEE
Tallahassee
1964




AGRI.
CULUA
FLORIDA STATE BORIM' OF
CONSERVATION
FARRIS BRYANT Governor
TOM ADAMS RICHARD ERVIN
Secretary of State Attorney General
J. EDWIN LARSON RAY E. GREEN
Treasurer Comptroller
THOMAS D. BAILEY DOYLE CONNER
Superintendent of Public Instruction Commissioner of Agriculture
W. RANDOLPH HODGES Director
ii




LETTER OF TRANSMITTAL
Jioria geoloqircal Survey
Callakassee
October 10, 1963
Honorable Farris Bryant, Chairman Florida State Board of Conservation Tallahassee, Florida
Dear Governor Bryant:
The Division of Geology is publishing as Florida Geological Survey Report of Investigations No. 35, a comprehensive report on the water resources of Alachua, Bradford, Clay, and Union counties, Florida, which was prepared by William E. Clark, R. H. Musgrove, Clarence G. Menke and Joseph W. Cagle, Jr., as part of a cooperative program with this department.
These counties include one of the high pressure areas n the artesian system of Florida, and the study permits, for the first time, when combined with studies being made in St. Johns, Flagler, and Putnam counties to the east, the observation of important portions of the ground-water cycle, ranging from recharge under water table conditions through recharge to the artesian system, movements toward the coast and discharge along the coast. It also permits the observation of changes in the distribution of pressures of such a system with the use of water along the coastal areas. We are pleased to publish this timely information.
Respectfully yours,
Robert O. Vernon
Director and State Geologist
111




Completed manuscript received
May 9, 1963
Published for the Florida Geological Survey By The E. O. Painter Printing Company DeLand, Florida
Tallahassee
1964
iv




CONTENTS
Abstract 1 Introduction 4 1Purpose and scope 4 Previous investigations 6 Methods of investigation - 7 Description of area - --- 9
Topography (
Geology 11
Eocene Series 12 Oligocene Series 20 Miocene Series 21 Miocene to Pleistocene (?) Series 23 Pleistocene Series 24.
Pleistocene and Recent Series 26 Structure 27
Climate __ 28
Temperature ----28 Rainfall 30 Surface water c
St. Johns River ___ 37 Black Creek basin 38 Santa Fe River basin 50 Orange Creek basin 56 Etonia Creek basin 60 Quality of surface waters 65
Introduction 65 Explanation of terms 75 Water temperature 76 Factors affecting chemical quality 77 Santa Fe River basin 88 Black Creek basin ------93
North Fork Black Creek 93 South Fork Black Creek 95
Etonia Creek basin 99 Orange Creek basin _99 Ground water 102
Limitations of -yield 103 Upper aquifers 110
Water-table aquifer 110
Configuration of water table 112 Recharge and discharge 113 Fluctuation of the water table 113 Wells 115
Secondary artesian aquifers .115
Piezometric surfaces 115 Fluctuation of the piezometric surfaces 117 Movement 118
V




Wells 118
Floridan aquifer 120
Hydraulic properties _120 Piezometric surface 122
Recharge
Discharge 126 Discussion of Floridan aquifer by counties 127
Alachua County 127
Fluctuation of piezometric surface --127 Area of artesian flow 127 Analysis of pumping test 127 Specific capacities of wells 131
Bradford County 134
Fluctuation of piezometric surface 134 Specific capacities of wells 134
Clay County 134
Fluctuation of piezometric surface 134 Area of artesian flow 134 Specific capacities of wells 134
Union County ------ 137
Fluctuation of piezometric surface 137 Specific capacities of wells 137
Quality of ground water ------ 138
Factors affecting chemical quality 139 Water-table aquifer 139 Secondary artesian aquifer 145 Floridan aquifer _--147 Variability of water quality 148 Ground-water temperature 151 Water use 152
Relation of water quality to water use 152
Domestic use and public supplies 153 Agricultural use 155 Industrial use 157
Surface water ------ 159 Ground water 160 Summary --_162 References 166
ILLUSTRATIONS
Figure Page
1 Florida showing the locations of Alachua, Bradford, Clay, and
Union counties _5
2 Alachua, Bradford, Clay, and Union counties, Florida, showing
the location of wells -facing 8
3 Explanation of well-numbering system 9
4 Generalized geologic map of Alachua, Bradford, Clay, and Union
counties, Florida showing the approximate elevation of the top
of the Ocala Group and the locations of geologic sections __ Facing 12
vi




5 West-east geologic section in Alachua, Bradford, and Clay counties, Florida, along line A-A' in figure 4 .13
6 West-east geologic section in Alachua, Bradford, and Clay
counties, Florida, along line B-B' in figure 4 .14
7 Southwest-northwest geologic section in Alachua and Union
counties, Florida, along line C-C' in figure 4 15
8 South-north geologic section in Alachua, Bradford, and Union
counties, Florida, along line D-D' in figure 4 16
9 South-north geologic section in Alachua, Clay, and Bradford
counties, Florida along line E-E' in figure 4 17 10 Monthly mean temperatures 1912-1960,-at Gainesville, Florida 29 11 Rainfall at Gainesville, Florida, for the period 1900-60 30 12 Flow chart showing average flow of streams in Alachua, Bradford, Clay, and Union counties, Florida ----------------------- --- 36
13 Drainage map of the Black Creek basin showing data collection
sites -38 14 Channel-bottom profiles of streams in the Black Creek basin 40 15 Average runoff in inches per year from areas within the Black
Creek basin -------- -.-..-------. ... .. 41
16 Rainfall-runoff relation 42 17 Flow-duration curves for streams in the Black Creek basin 44 18 Discharge available without storage for South Fork Black
Creek near Penney Farms, Florida (1939-60) -------------45
19 Discharge available without storage for North Fork Black
Creek near Middleburg, Florida (1932-60) 45 20 Hydrographs of floods during May 20-25, 1959, in the Black
Creek basin ---------46
21 Flood frequency curves for the Black Creek basin 47 22 Depth contours of Whitmore Lake 48 23 Stage duration curve for Kingsley Lake (1947-60) 49 24 Depth contours of Kingsley Lake 50 25 Drainage map of the Santa Fe River basin showing data
collection sites 51 26 Average runoff in inches per year from areas within the Santa
Fe River basin 52 27 Flow hydrographs for the Santa Fe River 53 28 Flow-duration curves for streams in the Santa Fe River basin ___ 55 29 Stage graphs of Santa Fe Lake, Lake Sampson, and Lake Butler 56 30 Drainage map of the Orange Creek basin showing data collection sites --- 57 31 Flow-duration curves for streams in the Orange Creek basin 59 32 Stage-duration curves for Newnans Lake, Orange Lake, and
Lochloosa Lake ___ 61 33 Stage graphs for Newnans Lake 62 34 Stage graphs for Orange Lake 62. 35 Stage graphs for Lochloosa Lake 63 36 Drainage map of the Etonia Creek basin showing data
collection sites 64 37 Depth contours of Blue Pond 65 38 Depth contours of Sand Hill Lake ---- 66 39 Depth contours of Magnolia Lake ------------------- 67
vii




40 Depth contours of Crystal Lake ..68 41 Depth contours of Brooklyn Lake 69 42 Depth contours of Keystone Lake 70 43 Depth contours of Lake Geneva ------------71
44 Depth contours of Loch Lommond 72 45 Stage graphs of nine lakes near Keystone Heights, Florida 73 46 Profile of lakes near Keystone Heights, Florida 74 47 Water budget of Brooklyn Lake for the period October 1957
to September 1960 74 48 Residue on evaporation at 1800C, hardness, and organic matter
in relation to specific conductance, Santa Fe River at Graham,
Florida, July 1957 to September 1960 ... .. 89 49 Specific conductance in relation to flow, Santa Fe River at
Graham, Florida July 1957 to September 1960 _-90 50 Cumulative frequency curve of specific conductance of selected
streams (periodic samples) 91 51 Cumulative frequency curve of residue of selected streams
(periodic samples) 92 52 Cumulative frequency curve of some of selected streams
(periodic samples) ----------.. 93
53 Cumulative frequency curve of color of selected streams
(periodic samples) 94 54 Residue on evaporation at 1800C, hardness, and organic matter
in relation to specific conductance, New River near Lake Butler,
Florida, July 1957 to September 1960 95 55 Specific conductance in relation to flow, New River near Lake
Butler, Florida, July 1957 to September 1960 96 56 Cumulative frequency curves of selected characteristics of
water from New River near Lake Butler, Florida, October
1957 to September 1958 .. ....97 57 Residue on evaporation at 1800C, hardness, and organic matter
in relation to specific conductance, Santa Fe River at Worthington, Florida, July 1957 to September 1960 -- 98 58 Specific conductance in relation to flow, Santa Fe River at
Worthington, Florida, July 1957 to September 1960 99 59 Cumulative frequency curves of selected characteristics of water
from Santa Fe River at Worthington, Florida, October 1957
to September 1958 100 60 Residue on evaporation at 1800C, hardness, and organic matter
in relation to specific conductance, Olustee Creek near Providence, Florida, July 1957 to September 1960 101 61 Specific conductance in relation to flow, Olustee Creek near
Providence, Florida, July 1957 to September 1960 101 62 Residue on evaporation at 180C00, hardness, and organic matter
in relation to specific conductance, Santa Fe River at High
Springs, Florida, July 1957 to September 1960 -102 63 Specific conductance in relation to flow, Santa Fe River at High
Springs, Florida, July 1957 to September 1960 103 64 Cumulative frequency curves of selected characteristics of water
from Santa Fe River near High Springs, Florida, October 1958
to September 1959 ___ 104
viii




65 Residue on evaporation at 180C00, hardness, and organic matter
in relation to specific conductance, North Fork Black Creek near
Highland, Florida, July 1957 to September 1960 .. ... .------------ -- 105
66 Residue on evaporation at 180-0C, hardness, and organic matter
in relation to specific conductance, North Fork Black Creek near
Middleburg, Florida, July 1957 to September 1960 106 67 Specific conductance in relation to flow, North Fork Black Creek
near Highland, Florida, July 1957 to September 1960 107 68 Specific conductance in relation to flow, North Fork Black Creek
near Middleburg, Florida, July 1957 to September 1960 -------------107
69 Cumulative frequency curves of selected characteristics of water
from North Fork Black Creek near Highland, Florida, October
1958 to September 1959 108 70 Residue on evaporation at 1800C, hardness, and organic matter
in relation to specific conductance, South Fork Black Creek
near Penney Farms, Florida, July 1957 to September 1960 109 71 Specific conductance in relation to flow, South Fork Black Creek
near Penney Farms, Florida, July 1957 to September 1960 110 72 Cumulative frequency curves of selected characteristics of water
from South Fork Black Creek near Penney Farms, Florida,
October 1958 to September 1959 __ _111 73 Generalized geologic section from Archer to Orange Park,
Florida showing aquifers and the movement of water 112 74 Alachua, Bradford, Clay, and Union counties, Florida showing
generalized contours on the water table in the water-table
aquifer .. ... . --------- ------ Facing 112
75 Hydrographs of wells 946-226-1, 000-232-1, 956-208-1, and
946-202-3 114 76 Geologic sections showing typical water levels in wells tapping
different aquifers _- .- 116 77 Hydrograph of well 946-206-1 near Waldo, Florida 117 78 Alachua, Bradford, Clay, and Union counties, Florida showing
contours on the top of the Floridan aquifer 121 79 Semilog plot of residual drawdown versus the ratio of the
time since pumping started to the time since pumping stopped,
showing solution for coefficient of transmissibility 122 80 Alachua, Bradford, Clay, and Union counties, Florida showing
contours on the piezometric surface of the Floridan aquifer
in June 1960 Facing 124 81 Hydrographs of wells 927-203-1, 929-213-1, 932-231-1, 936-236-1,
941-222-2, and 946-226-2 in Alachua County, Florida 128 82 Hydrographs of wells 948-231-2 and 949-236-2, in Alachua
County, Florida -- -129 83 Southeastern Alachua County, Florida showing the approximate
area of artesian flow in June 1960 130 84 Graph showing theoretical drawdowns in the vicinity of a well
pumping 1,000,000 gpd for selected periods 131 85 Clay County, Florida showing the decline of the piezometric
surface in eastern Clay County from June 1934 to June 1960 __ 136 86 Hydrographs of wells 959-140-1, 002-142-1, 006-149-1, and
003-151-1 in Clay County, Florida ---------- 137
ix




87 Clay County, Florida showing the approximate area in which wells tapping the Floridan aquifer will flow, June 1960 _138 88 Hydrograph of well 007-222-1 in Union County, Florida and a graph of monthly rainfall at High Springs, Florida 142 89 Dissolved solids and hardness of water from the water-table aquifer _144
90 Dissolved solids and hardness of water from the secondary artesian aquifers 146
91 Dissolved solids and hardness of water from the Floridan aquifer 149
92 Alachua, Bradford, Clay, and Union counties, Florida showing.
centers of concentrated pumping and estimated use of ground
water in 1960 161
TABLES
Table Page
1 Geologic formations penetrated by water wells in Alachua,
Bradford, Clay, and Union counties, Florida 18
2 Departure from average rainfall, in inches, at Gainesville, Florida 31
3 Locations of gaging stations, types of surface-water data collected, and periods of records- .. ....32
4 Maximum, minimum, and average of observed daily water temperatures of streams in Alachua, Bradford, Clay, and Union
counties, Florida 76
5 Average, maximum, and minimum values observed for substances dissolved in streams and lakes ... 78
6 Specific capacities of wells tapping secondary artesian aquifers 119
7 Specific capacities of wells tapping the Floridan aquifer in
Alachua County, Florida 132
8 Specific capacities of wells tapping the Floridan aquifer in
Bradford County, Florida .135
9 Specific capacities of wells tapping the Floridan aquifer in
Clay County, Florida 14- 140
10 Specific capacities of wells tapping the Floridan aquifer in
Union County, Florida 143
11 Chemical quality of water tests commonly made for purposes
indicated 152
12 Water-quality characteristics and their effects 154 13 Suggested water-quality tolerances 158 14 Suggested water-quality tolerance for boiler feed water 159




PREFACE
This report was prepared by the Water Resources Division of the U. S. Geological Survey in cooperation with the Florida Geological Survey. The investigation was under the general supervision of M. I. Rorabaugh, district engineer, Ground Water Branch; A. 0. Patterson, district engineer, Surface Water Branch; and J. W. Geurin, district chemist, succeeded by K. A. MacKichan, district engineer, Quality of Water Branch, of the U. S. Geological Survey.
The writers wish to express their appreciation to the citizens of Alachua, Bradford, Clay, and Union Counties for supplying data and permitting the sampling and measuring of their wells and to the well drillers for furnishing well cuttings, water-level data, and other helpful information. Thanks are due the U. S. Soil Conservation Service for its assistance in drilling a number of shallow test wells and to Dr. E. C. Pirkle, of the University of Florida, who furnished valuable geologic information.
xi




WATER RESOURCES
OF
ALACHUA, BRADFORD, CLAY, AND UNION COUNTIES, FLORIDA
By
William E. Clark, Rufus H. Musgrove,
Clarence G. Menke, and Joseph W. Cagle, Jr.
ABSTRACT
Alachua, Bradford, Clay, and Union counties are within the topographic division of Florida known as the Central Highlands, except eastern Clay County which is a part of the Coastal Lowlands. The most striking topographic features are: Trail Ridge, which extends through the area in a north-south direction; high swampy plains in the northwestern part of the area; rolling, sloping, lands that are well dissected by stream channels in the eastern part of the area; and lower, slightly rolling plains in southwestern Alachua County, which are devoid of stream channels but which are dotted with sinks and limerock pits.
The area is underlain by a series of limestones and dolomites to depths of several thousand feet. The upper several hundred feet of these beds include the Lake City Limestone and Avon Park Limestone of Eocene age. The Ocala Group, the uppermost Eocene unit, is exposed in southern and western Alachua County, but its top is about 250 feet below sea level in eastern Clay County. In the extreme southwestern corner of Alachua County the Ocala Group is covered by about 35 feet of sands and clays of the Alachua Formation of Miocene to Pleistocene age, but in other parts of the area it is overlain by as much as 250 feet of relatively impervious beds of clay, sandy clay, and limestone of the Hawthorn Formation of Miocene age and by deposits of late Miocene age. In southwestern Clay County and southeastern Bradford County the Miocene deposits are beneath about 90 feet of sand and clayey sand that comprise the unnamed coarse plastics of Pleistocene age. Elsewhere within the area, the Miocene deposits are overlain by a series of higher terrace deposits of Pleistocene age and by a series of lower terrace deposits of Pleistocene and Recent age. The higher terraces are made up of the older Pleistocene terrace de-




2 FLORIDA GEOLOGICAL SURVEY
posits which form most of the land surface in Bradford and Union counties and extensive areas in Alachua and Clay counties. The thickness of the older Pleistocene terrace deposits generally is 40 feet or less, but in some places it is as much as 130 feet. Pleistocene and Recent sand, clay, and marl deposits cover older beds to depths ranging generally up to 60 feet in Clay County. The principal structure of the area is the Ocala uplift, whose crest transverses southwestern Alachua County. The regional dip of formations on the flank of the uplift is east-northeast at an average rate of about
6 feet per mile.
The average annual temperature at Gainesville is 700F. Only rarely does the temperature reach 100'F and only occasionally does it drop into the teens. In fact, 280 frost-free days per year can be expected.
Uneven distribution of rainfall causes most of the water problems in the area. On the average, the area receives 52 inches of rainfall per year. However, there have been considerable variations from the average which have caused both floods and droughts. Minor seasonal floods are a common occurrence. The greatest floods of record occurred in 1948-49. For the 6-year period ending in 1949 the excess rainfall at Gainesville was 45.87 inches.
The most severe drought of record occurred during 1954-57. Rainfall at Gainesville was deficient by 22.66 inches during 195456. Many of the streams reached their lowest flow of record and several lakes lost most of their water during 1954-57. Orange Lake in southern Alachua County was reduced to one-fifth of its normal size, and Brooklyn Lake at Keystone Heights was reduced to one-half of its normal size.
The average streamflow from the four counties is approximately 1,150 mgd (million gallons per day) and leaves the area through four stream basins that originate within the area (Black Creek, Santa Fe River, Orange Creek, and Etonia Creek). In addition, the St. Johns River, the largest and longest river wholly within Florida, flows northward along the eastern boundary of Clay County and has an average flow of about 4,500 mgd at Green Cove Springs.
Average runoff from the four counties is about 12 inches per year but varies considerably from area to area. Average yearly runoff from the Black Creek basin is 14.8 inches; from the Santa Fe River basin, 22 inches; from the Orange Creek basin, 5 inches; and from Etonia Creek basin, less than 5 inches. An intervening segment of the Santa Fe River drainage area west of High Springs




REPORT OF INVESTIGATIONS NO. 35 3
has an average runoff of 85 inches per year, which is possibly the highest runoff from any area in Florida.
There are more than 50 lakes in the four counties that exceed 0.02 square mile in size, the largest of which is 25.7 square miles in size. The combined area of all these lakes is about 90 square miles. The elevations above sea level of the lakes range from 57 feet for the lowest to 176 feet for the highest. Stages of some lakes have fluctuated as much as 20 feet; others have fluctuated only 3.5 feet. Soundings have been made in 9 lakes, the deepest of which, Kingsley Lake, has a depth of 85 feet. The depths of most of the lakes are in the range from 20 to 40 feet.
Concentration of substances dissolved in surface water ranged from 10 to 299 ppm (parts per million). All surface water, except in the Etonia Creek basin in southwestern Clay County, is colored. The color intensity ranged from 0 to 1,000 platinum-cobalt scale units. Except for the New River near Lake Butler and Santa Fe River at High Springs, the surface water is characteristically soft. Generally, the hardness (as calcium carbonate) is less than 50 ppm.
The two major sources of ground-water supplies in these counties are the upper aquifers and the Floridan aquifer. The upper aquifers are above the Floridan aquifer except where they are absent in southern and western Alachua County.
The upper aquifers are composed of a water-table aquifer and secondary artesian aquifers. The water-table aquifer consists mostly of shallow sand or clayey sand of Miocene, Pleistocene, and Pleistocene and Recent age. These sands, which are recharged locally by rainfall, yield water to domestic wells. The secondary artesian aquifers, which are sandwiched between the water-table aquifer and the Floridan aquifer, consist chiefly of limestone layers of the Hawthorn Formation or Choctawhatchee Formation. Probably more wells in these four counties withdraw water from secondary artesian aquifers than from any other aquifer. These aquifers supply sufficient water for domestic and livestock purposes.
The source of the largest supplies of ground water is the Floridan aquifer, which consists mostly of limestones of Eocene and Oligocene age. In the area west of a line running through Gainesville in a southeast-northwest direction, water in the Floridan aquifer is under water-table conditions; and in the area east of this line the water is under artesian conditions. The piezometric surface of the Floridan aquifer is. high near the junction of the Alachua, Bradford, Clay, and Union county lines, indicating a




4 FLORIDA GEOLOGICAL SURVEY
recharge area. The rate of recharge in this area is estimated to Sbe at least 1.8 inches of water per year. In southern and western Alachua County where the Floridan aquifer is exposed; at least 10 inches of water per year percolates to the Floridan aquifer. The principal area of artesian flow from the Floridan aquifer includes most of northeastern Clay County and the low areas along the St. Johns River, Black Creek, and Little Black Creek.
Although about 10 billion gallons of ground water were used in the four counties in 1960, it is a relatively undeveloped resource. Hundreds of millions of gallons of additional ground water a year probably can be developed at almost any place in the four counties if the development is based on sound scientific principles and adequate hydrologic data.
Concentration of substances dissolved in ground water ranged from 14 to 687 ppm. Except for the water in the water-table aquifer, the ground water is characteristically moderately hard to hard. Often the hardness is greater than 100 ppm. Except for localized flat and swampy areas, the color intensity of the ground water is generally 10 or less.
Iron in concentrations greater than 0.30 ppm occurs in both surface waters and ground waters. The occurrence of iron in excess of 0.30 ppm is less prevalent in water from the secondary artesian aquifers and from the Floridan aquifer than from the water-table aquifer.
INTRODUCTION
PURPOSE AND SCOPE
Water is a valuable natural resource in Alachua, Bradford, Clay, and Union counties (fig. 1) but had been given little thought by local residents before the severe drought of 1954-57. The drought focused the attention of local- officials upon the usable water-supply limitations and the need for information concerning the water resources in the area. This attention was stimulated by the distressingly low water level of Brooklyn Lake near Keystone Heights.
Local officials presented the problem to the State Legislature. The Legislature provided funds to the Florida Geological Survey for a water-resources investigation. With these funds from the Florida Geological Survey and matching funds from the Federal Government, a cooperative agreement was reached between the Florida Geological Survey and the U. S. Geological Survey to




REPORT OF INVESTIGATIONS NO. 35 5
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Florido by U.S. Geological Survey Figure 1. Florida showing the locations of Alachua, Bradford, Clay, and Union counties.




6 FLORIDA GEOLOGICAL SURVEY
conduct the water-resources study. This report is to document the results of the study for public use.
The investigation was designed to obtain data fundamental to solving water problems of the area. These data are to be published by the Florida Geological Survey in an Information Circular entitled "Water-Resources Data of Alachua, Bradford, Clay, and Union Counties, Florida." Special attention was directed toward the causes of the fluctuations of Brooklyn Lake during the investigation, and the results of this part of the investigation are published by the Florida Geological Survey in Report of Investigation 33, entitled "Hydrology of Brooklyn Lake Near Keystone Heights, Florida."
High and low lake stages, floods, low streamflow, chemical content of waters, low artesian pressures, decreased well yields, and water temperatures are problems.
Questions most frequently asked about water and water supplies are: (1) Where is a supply located? (2) How much is available?
(3) What are the fluctuations of this supply? (4) What causes the fluctuations of a supply? and (5) What are the chemical and physical characteristics of the supply? All these questions are best answered by data on streamflow, lake and stream stages, areas and depths of lakes, drainage areas, wells, geology, ground-water levels, rainfall, and the physical and chemical character of water. These measurements should be made over a long period of time, to include both high-water and low-water conditions.
PREVIOUS INVESTIGATIONS
Records of streamflow have been collected by the U. S. Geological Survey at various points in the area since 1927. These records were published annually in a series of water-supply papers, and a summary of these records through 1950 is published in Water-Supply Paper 1304. The results of a low-flow study of streams during April and May 1956 were given in a report by Pride (1961). Pride (1958) reported on the frequency of floods in this area. Black and Brown (1951) gave information about the chemical quality of water in the area and other parts of Florida.
A series of water-supply papers contain measurements of artesian pressure in several wells in northeastern Clay County. Ground-water resources and geology of the four counties were mentioned in a report by Matson and Sanford (1913). Artesian water supply, well descriptions, measurements of water levels in wells, and chemical analyses of water from wells were reported




REPORT OF INVESTIGATIONS No. 35 7
by Sellards and Gunter (1913). Stringfield (1936) reported well locations and well descriptions, and prepared a piezometric map of the principal artesian aquifer of the Florida Peninsula. Ferguson, and others (1947) discussed some of the larger springs of Florida.
A report by Cooper and others (1953) includes a general discussion of the water resources of these four counties. White (1958) relates water resources to landforms of the peninsula and makes brief references to Alachua County. The most comprehensive geological reports are those of Cooke and Mossom (1929) and Cooke (1945), both entitled "Geology of Florida," which describe the formations that crop out in the four counties and give details of their occurrence. A geological map of the surface formations accompanies each of these reports. Vernon (1951) has drawn structural maps that include Alachua, Bradford, Clay, and Union counties. A geological map by Vernon (1951), revised from the earlier map by Cooke (1945), shows the outcrop of the surface formations. Pirkle (1956) has contributed papers on the geology and physiography of Alachua County. A report by Puri (1957), describes the Ocala Group and its fossils at several quarry exposures in Alachua County and shows subsurface sections that extend across parts of the four-county area. Puri and Vernon (1959) give detailed descriptions of geologic sections and show panel diagrams of the subsurface geology in the counties.
METHODS OF INVESTIGATION
The surface-water investigation consisted of collecting stage records on lakes and streams; measuring the flow of streams; sounding lakes with a sonic depth recorder; and determining the limits of drainage areas.
Field mapping of the surface occurrence of the geologic formations was made by using rock outcrops in roadcuts, streams, and channels; exposures in quarries and sinks; and the application of such geologic aids as vegetation, topography, and surface drainage features. The interpretation of the subsurface geology is based on a microscopic examination of the character, composition, and fossils of drill cuttings from approximately 70 wells and from studies of numerous drillers' logs of wells. I-The following data on existing wells were collected at the time the wells were canvassed; drillers' logs, water use, yield of wells, dimensions of casings, depth of wells, depth to water, and water temperature. Water samples were also collected for chemical .analyses. Figure 2 shows the locations of wells that were




8 FLORIDA GEOLOGICAL SURVEY
inventoried. Figure 3 gives an explanation of the well-numbering system and shows how a well may be located on the map by its number.
A large part of the investigation was devoted to drilling and collecting data from 84 test wells. Forty-two of the test wels were 1 inchesin diameter and 50 feet or less in depth. Only geologic samples were collected from these wells. Twenty-seven of the test wells were 2 inches in diameter and were drilled near Brooklyn Lake. Twelve of the 2-inch wells, which ranged from 28 to 67 feet in depth, were drilled to obtain water-level measurements. The remaining 2-inch wells, which ranged in delth from 77 to 449 feet, were drilled to obtain water-level measurements, water temperatures, geologic samples, and water samples. Four 6-inch wells were drilled near Brooklyn Lake to obtain geologic samples, water-level measurements, and water samples. Nine 4-inch and two 8-inch wells were drilled to obtain geologic samples, water samples, water-level measurements, and water temperatures.
Some of the test wells and some of the existing wells were pumped or allowed to flow to obtain information on the yield of the wells and to obtain information concerning the hydraulic characteristics of the material that the wells penetrated. In addition, the elevations of a number of the existing wells and a number of the test wells were determined with either an engineer's level or an altimeter.
Water levels and water temperatures were measured periodically in a selected number of existing wells and in most of the test wells. On a few key wells, automatic water-level recorders were installed to obtain a continuous record of the water-level fluctuations.
Water samples were collected and analyzed using standard methods (Rainwater and Thatcher, 1960). Samples of water for chemical analyses were taken at streamflow-measuring stations when practical. The analyses of these samples were used to estimate the quality of water at other locations. Water samples were collected preferably from wells for which well depth, depth of casing, geologic formation of materials, and elevation of the water surface in the well were known. The analyses of these samples were used to estimate the ground-water quality.
DESCRIPTION OF AREA
Alachua, Bradford, Clay, and Union counties are grouped together in the northern part of peninsular Florida (fig. 1). The




45 40' 35' 25 20' I15' I0 05 82*00 55 50' 45' 40 35! 8*3'
---I -- 11T
EXPLANATION 0,
2 ___-l _DUVAL COUNTY
Inventoried wee and number L NTY NG
=t
Shallow test well BAKER COUNTY-0.. ... -to T --I u- I
___ I _Deep test well tapping U OT nCOUN Y
the Floridan aqurfer a o d re
02.2 _7 22 2 0 G fll
.. 2 e I LY22S6 22
1.2! L B 2
. . .. . .. -y -
___-C O~i flTI -__ iij7_S'.2~BROOKER 2 ( _-T-T _- i- -- 'A II 'U
to I 2..-~l I reRodOeolmn mopsoi ._. ._9_ onsn__ UN___Th Y LI
0 RD FT
HGHSPNG -rn *
t e P 28204c 03 02 82 00
34_ **,z z 7 59 6 .
.2, 1.2 INP 2L 1 12 2PNE *
MARIOR CUNTYA2M 4
a Som S ID t 0c Qadrongres O 2 3 m Ies
Figure 2. Alachua, Bradford, Clay, and Union counties, Florida, showing the location of wells.




REPORT OF INVESTIGATIONS No. 35 9
Degrees of longitude west of Greenwich England, prime meridian
83* 82* 1
310
EXPLANATION NASSAU
The well-numbering system in Florida is
derived from latitude and longitude
coordinates on a state-wide grid of I BA
I-minute parallels of latitude and I- "
minute meridians of longitude. The -wells in a I-minute quadrangle are ,. I N/
numbered consecutively in the order I 30 inventoried. In Florida, the latitude 1 C7-' cLY ST (
and longitude prefix north and west rand the first digit of the degree 'o
number are not included in the well i AL ACHUA
number. aTA.6"
The well-number is a composite of --three numbers separated by hyphens:
the first number is composed of the LE V Y
lost digit of the degree and the two MAR N
digits of the minutes that define the latitude on the south side of the Iminute quadrangle; the second num- 290
ber is composed of the last digit of
the degree and two digits of the .... .... 3000'
minutes that define the longitude on I f
the east side of a I-minute quad- ... .
rangle; and the third number gives
the numerical order in which the
well was inventoried in the I-minute
quadrangle 2945
------- .... ,, ~fR:: ,, -l .... :
29*28' +9 11 29030'
29027'
el
*2 29015'
82*33' 82*32' 8231' 8230
Well number 926-230-3
Z 2900'
83000' 82045' 82030' 82015' 82000' Well-number 926-230-3 was the third
well inventoried in the I-minute quadrangle north of the 29026' parallel of latitude and west of the 82030' meridian of longitude.
Figure 3. Explanation of well-numbering system.
area is in the vicinity of latitude 29050' N., longitude 82010' W.
It extends about 50 miles north-south and about 65 miles east-west.
The east edge of the area is 20 miles from the Atlantic Ocean and
the southwest corner is 30 miles from the Gulf of Mexico.
Trade, manufacturing, mining, agricultural, and governmental
operations are the main sources of income. Revenues associated
with recreational activities are increasing as the potential of the
area is recognized. Although no water is consumed by recreational
activity, more of the lakes are being used for this purpose as the




10 FLORIDA GEOLOGICAL SURVEY
economy of the area expands. At present, the operations of municipalities, mining, and agriculture require the largest quantities of water in the area.
The four counties have an area of 2,023 square miles and had a population of 103,800 in 1957. The area and the population density of the counties are: Alachua, 892 square miles, 77 persons per square mile; Clay 598 square miles, 26 persons per square mile; Bradford, 293 square miles, 41 persons per square mile; and Union, 240 square miles, 33 persons per square mile. The four counties combined have 51 persons per square mile, whereas the state as a whole has 76 persons per square mile. (The population figures are from data by the Bureau of Business and Economic Research, University of Miami, Coral Gables, Florida.)
TOPOGRAPHY
The area is within the topographic division of the state known as the Central Highlands, except eastern Clay County, which is in the Coastal Lowlands division (Cooke, 1945, p. 8, 10, 11). The principal topographic features of the area are: Trail Ridge, which extends through the area in a north-south direction; the high swampy plains in central, north-central, and northwestern parts of the area; the rolling, sloping lands in the eastern part of the area which are well dissected by stream channels; and the slightly rolling plain in southern and western Alachua County, which is devoid of stream channels but which is dotted with sinks and limerock pits.
Train Ridge extends from the lake region in the vicinity of Keystone Heights in southwestern Clay County northward along the Bradford-Clay County line. This ridge is a series of sandhills, the highest of which (elevation 250 feet) is just south of Kingsley Lake. From the highest point, the land slopes southward and fans out into a wide area of sandhills, which is dotted with lakes, in the vicinity of Keystone Heights. Farther south, in Putnam County, the land is flat and has many shallow lakes.
North of Kingsley Lake, the ridge is narrow and generally is less than a mile wide across the crest. It slopes downward slightly to about 200 feet above msl (mean sea level) at the Baker County line.
East of Trail Ridge, in Clay County, the land slopes toward the St. Johns River for a distance of 20 to 25 miles. The land along the St. Johns River in this area generally is less than 10 feet above sea level. Many well-defined channels drain directly from the east




REPORT OF INVESTIGATIONS NO. 35 11
side of the ridge. Some of the headwater streams of the North Fork Black Creek have channel slopes of 50 feet per mile.
The west side of Trail Ridge slopes steeply, as much as 100 feet per mile, to a swampy plain. This plain extends over parts of Alachua, Bradford, and Union counties and ranges generally from 125 to 175 feet above msl. No well-defined stream channels drain the west side of the ridge; however, several streams originate in areas occupied by the swampy plain.
In southern and western Alachua County the land is fairly fiat but there are gently rolling hills. This area is dotted with small ponds and pits made by mining of limestone. A significant feature of this area is the absence of stream channels.
GEOLOGY'
Alachua, Bradford, Clay, and Union counties are underlain by several hundred feet of unconsolidated to semiconsolidated marine and nonmarine deposits of sand, clay, marl, gravel, limestone, dolomite, and dolomitic limestone. The oldest formation penetrated by water wells in the four counties is the Lake City Limestone of Eocene age. However, the Oldsmar Limestone of Eocene age, which lies below the Lake City, probably is fresh water-bearing, at least in part. The Oldsmar Limestone, at least in part, and the overlying younger formations contain fresh water, but several thousand feet of older rocks of Tertiary and Cretaceous age that lie below the Oldsmar contain highly mineralized water. Only the fresh water-bearing formations are discussed in this report.
The Eocene Series comprises the Oldsmar Limestone, Lake City Limestone, Avon Park Limestone, and Ocala Group; the Oligocene Series is represented by the Suwannee Limestone; the Miocene Series comprises the Hawthorn and Choctawhatchee Formation and, in part, the Alachua Formation; the Pleistocene Series is made up of the unnamed coarse clastics, the older Pleistocene terrace deposits, and, in part, the Alachua Formation; and the Pleistocene and Recent Series is made up of the younger marine and estuarine terrace deposits. These deposits underlie a terrain that is a series of marine terraces or plains; a hill and valley, and
'The stratigraphic nomenclature used in this report conforms to the usage by Cooke (1945) with revisions by Vernon (1951) except that the Ocala Limestone is referred to as the Ocala Group. The Ocala Group, and its subdivisions as described by Puri (1953), has been adopted by the Geological Survey of Florida. The Federal Geological Survey regards the Ocala as a formation, the Ocala Limestone.




12 FLORIDA GEOLOGICAL SURVEY
hill and lake topography; and a limestone plain. Except for the Inglis, Williston, and Crystal River Formations that compose the Ocala Group, which is undifferentiated in this report, erosional unconformities separate each formation. A generalized geologic map (fig. 4), which is a modification of the previous geologic maps of the area by Cooke and Mossom (1929), Cooke (1945), Vernon (1951), and Purl and Vernon (1959), shows the surface occurrence of the various formations. The oldest exposed rocks are limestones of the Ocala Group, which crop out in southern and western Alachua County.- The Hawthorn, Choctawhatchee, and Alachua Formations, the unnamed coarse clastics, the older Pleistocene terrace deposits, and the Pleistocene and Recent deposits are at the surface in other parts of the four-county area. Geologic sections (figs. 5, 6, 7, 8, and 9) show thickness, structure, topographic expression, and the stratigraphic position and relationship of the formations.
The geologic formations penetrated by water wells in the four counties are listed in table 1, which gives a brief description of their thickness and physical character. The formations are grouped according to their geologic age and are described from oldest to youngest-that is, from the Oldsmar Limestone of Eocene age to the Pleistocene and Recent deposits.
EOCENE SERIES
The Oldsmar Limestone, the lowermost formation of Eocene age, lies at relatively great depths in .Alachua, Bradford, Clay, and Union counties and is not penetrated by water wells in this area. Although a few oil test wells penetrate the Oldsmar in the four counties, the data from these wells are inconclusive relative to the thickness and character of the formation. Vernon (1951, p. 87), however, describes the thickness and lithology of the Oldsmar, based on oil test wells, in Levy County which adjoins Alachua County on the southwest. Vernon states, regarding the Oldsmar, that "it is composed essentially of fragmental marine limestones, partially to completely dolomitized and containing irregular and rare lenses of chert, impregnation of gypsum and thin shale beds." The thickness of the formation in Levy County ranged from 380 to 568 feet in five test oil wells. The Oldsmar overlies the Cedar Keys Limestone of Paleocene age.
The Lake City Limestone of Eocene age is the oldest formation from which supplies of fresh ground water are obtained in the area. The Lake City is nearest the surface along the crest of the Ocala uplift in southwestern Alachua County where its top was




: 40 35 30 25' 20' 5 ,0' 05' 8200' 55' 50' 45' 40' 35 t30
-291
DUVAL COUNTY -292 CL COUNTY /
BAKER C OUNTYUON
4 4 URG
ob
GREEN
r aaabe"t deot
CesAY CO U NT' anson /ePUTNAM COUNTY co -15
-1 08 A R SfXPL th a'10N
SonCon
Well for which dni n culers Younger norme and as n o are available uerrace deposits Well for which odr nrers lo n
is cCNu acble Oder Pmedtocene serrfce et aes ns Outcrop or Quarry 7IIM C40 I Unnameo coarse crostmcs A.amber reelose ns t e elevciton
1Z) dpof thto of he ouo- re o r heo Ba "5 Quid" qi
r feet, Teeernrrd le g in seap Alochua FormaBlonai
-40-- W < ru Contour represents the elevation ChoCtowhGicnee Formation of the top of the Oco o Group,
aeetdreea heore nferrsee Hoorn Formoion Con interval 40 feet.
~Ocala Group LE V Y Line pf geologic section
- -Z ] -- oe
pdoE ire6fEs show.n ais the outciop of the Choctownotcee Forrnction The cover of O0 Occlo Group, Hawthorn Fournction, illocnu0 sediments range in tnackness from 0 toa al ornotion, an the unnamed coarse clashes 15 feet D s.ed hne ndicales n erre CMARIO C U T ore covered by a veneer of sediments that Dsition of formation boundaresCOU Yore mostly loose sands and are, for the most Mod fied from mops oy Vernon 1951 and part, older Pleistocene terrace ceposts Pur, and Vernon 1959 Both ofier To e orti tnot cre P;e:stocene and Recent CooK 1945, deposits blonket Ine outcrop Of the
+40 0 3 e
[" 5 Toeeoonsc eadirongies
24F d re;)~ertt ma3ps
Figure 4. Generalized geologic map of Alachua, Bradford, Clay and Union counties, Florida, showing the approximate elevation of the Ocala Group and the location of geologic sections.




AA
_ PLEISTOCENE AND RECENT DEPOSITS 520 lb St 1k ,
00 ATI N FORMATION
0.. C A L A
-200
-o0 A v o"n 0m
-400 -------------
A- KEA----M. POMA AI ~-500 LAE
-600 Ol 4 omi.O, LIME ST 0 N E Ol----Figure 5. West-east geologic section in Alachua, Bradford, and Clay counties,
Florida along line A-A' in figure 4.




IA
OLDER PLEISTOCENE PLFSTOCEE AND TERRACE DEPOSITS ALENT DEPOSITS
O C A L N
-200
r
- o o "- O 0<
M00
Figure 6. West-east geologic section in Alachua, Bradford, and Clay counties, Florida, along line B-B' in figure 4.




G OLDER PLEISTOCENE TERRACE DEPOSITS FORMATION .
0 ",,,, ,- -,0
200
lm
,.,, -- -. t PA I
100- HAWTHORN 0 Di ~~HAWTHORNFOMTN
- N... L IMEST. F 0 NROU
- 4 00 4 k ... .
_ ~CITY ,
-500 0 I 2 4 6 8 miles LIMEST 0 N E LLI
..I
0 000
Figure 7. Southwest-northeast geologic section in Alachua and Union counties, Florida along line C-C' in figure 4.
k
z
-500- 0 12 4 6 8 lOmfles CIT LIMEIS TON E
Figure 7. Southwest-north east geologic section in Alachua and Union counties, Florida along line C-C' in figure 4.




OLDER PLEISTOCENE TERRACE DEPOSITS D~D'
HAWTHORN 114 eville
FM.6T
.b
100
.. F 0 R MA T I 0 N
o u
1-100- 4 L
-200 A V O N O
-400 4 nL Si
"0 IV
-500 ...... O N
L A K E C I T Y L IM ES T 0 N E
-600 0 I 2 4 6 a 10miles" .
Figure 8. South-north geologic section in Alachua, Bradford, and Union counties, Florida along line D-D' in figure 4.




L
REPORT OF INVESTIGATIONS NO. 35 17
OLDER PLEISTOCENE TERRACE DEPOSITS UNNAMED COARSE CLASTICS
20 awthorneo d E
Z 1
W N 0-- -0j HA0 WTH O
.1 EAIV 0 N RK
S-200
counties, Florida along line E-E' in figure 4.
penetrated by well 936-236-1, 21/32 miles south of Newberry, and
below msl, respectively. On a line from southwest to northeast across the four counties-that is, from the Ocala uplift, in the direction of greatest dip of the beds-the top of the Lake City lies at about 380 to 440 feet below ms1 at Gainesville, at about 600 feet below ms1 beneath the crest of Trail Ridge at Kingsley Lake, and at about 700 feet below ms1 at Green Cove Springs (fig. 5, 6). The Lake City Limestone overlies older Oldsmar Limestone of Eocene age.
Drill cuttings were available from only a relatively few, widely scattered wells penetrating the Lake City; therefore, the lithologic character and composition of the Lake City Limestone could be determined only generally. The cuttings show the formation to be composed mostly of tan, gray, and brown, hard, finely crystalline dolomite and dolomitic limestone. Included with these beds, however, are many softer layers of tan and gray, porous, fossiliferous limestone and seams of peat or lignite. The Lake City is most readily identified in drill samples with the first appearance of the Foraminifera, Dictyoconus americanu~s (Cushman) Since no water wells for which records were available were drilled through the Lake City Limestone, the thickness of the formation was not determined. The greatest penetration, 440 feet, was by well 938-221-1 at Gainesville.
The Avon Park Limestone, which overlies the Lake City Lime-HORN
stone. is in the subsurface throughout the four counties. The W o :,HAWTHORN
I4 FORMATION ~ 1000C A LA G ROU P
- 200-2 -300A VO0N P A RK L I MESO
0 1 2 ~4 6 oImiles
I -400
Figure 9. South-north geologic section in Alachua, Clay, and Bradford
counties, Florida along line E-E' in figure 4.
penetrated by well 936-236-1, 2 / miles south of Newberry, and well 938-236-3, at Newberry, at 150 feet below msl and at 168 feet below msl, respectively. On a line from southwest to northeast across the four counties-that is, from the Ocala uplift, in the direction of greatest dip of the beds-the top of the Lake City lies at about 380 to 440 feet below msl at Gainesville, at about 600 feet below msl beneath the crest of Trail Ridge at Kingsley Lake, and at about 700 feet below msl at Green Cove Springs (fig. 5, 6). The Lake City Limestone overlies older Oldsmar Limestone of Eocene age.
Drill cuttings were-available from only a relatively few, widely scattered wells penetrating the Lake City; therefore, the lithologic character and composition of the Lake City Limestone could be determined only generally. The cuttings show the formation to be composed mostly of tan, gray, and brown, hard, finely crystalline dolomite and dolomitic limestone. Included with these beds, however, are many softer layers of tan and gray, porous, fossiliferous limestone and seams of peat or lignite. The Lake City is most readily identified in drill samples with the first appearance of the Foraminifera, Dictyoconus arnericanus (Cushman). Since no water well& for which records were available were drilled through the Lake City Limestone, the thickness of the formation was not determined. The greatest penetration, 440 feet, was by well 938-221-1 at Gainesville.
The Avon Park Limestone, which overlies the Lake City Limestone, is in the subsurface throughout the four counties. The




'T'AldI 1, (Judogl iolImintionki f enetrated fly Water Wll, iII Alch ta, BIradlford, Clay, ani Union Countiv, Filorida,
00
s tit Format tthickness ]Physical characteristics (feet)
Pleistocene Sand and clayey sand, grey, brown and black, dissemni.
and Younger marine and estutrilne 80 nated organic matter beds of clay nmarl, and sandy clay, Recent terrace dielpoit:1 Shell marl and concentrations of shell in some areas,
Quaternary Sand, white to yellow, grey to black, clayey, organic Older P!elstocno terrace deposits 140 matter; varicolored clay, sandy clay and clayey sand.
Pleistocene P Sand and clayey sand, varicolored, locally contains quarts Unnamed coarse elastics 00 gravels, interbedded thin lenses of clay or kaolin,
0>
5 Sand, clay, and phosphate; boulders of siliceous limeSstone, flint and phosphate; vertebrate fossils.
Choctawhatchce Clay and mar], yellow to cream, indurated in part, phos. 0 Chotawhatch e 40 phate grains and pebbles, thin limestone and sand layers, Miocene Formation some shells.
-7- Clay and sandy clay, varicolored, Interbedded sand and sandy, phosphatic limestones; disseminated grains and Hawthorn Formation 250 pebbles of phosphate. Very hard limestone, partly dolomitic, in the lower part of the Hawthorn in some areas.
Tertary Oligoene Suwanee Limestone 50 Limestone, white to tan, soft to hard, porous, in part Tertiary Oligocene Suwannee Limestone fossiliferous and dolomitic.
Crystal River Formation Limestone, white, cream and tan, soft, granular, porous, Ocala Williston Formation 250 fossiliferous, coquinold in part. Some hard layers of Group Inglis Formation limestone and dolomitic limestone mostly in lower part.
(Undifferentiated)
Eocene' Dolomite, dark brown and tan, granular, hard, dense to Avon Park Limestone 210 porous : interbedded tan and cream limestone and dolomitice limestone.
Lake City Limestone 450 Limestone, dolomite, and dolomitic limestone, tan, grey, LakeCityLimetone41 0 and brown.




REPORT OF INVESTIGATIONS NO. 35 19
Avon Park in most parts of Alachua, Bradford, and Union counties is chiefly a dark brown to tan, granular, hard, dense to porous dolomite that in places contains a few beds of cream-colored limestone. Geologic logs of representative wells in Clay County, however, show many beds of tan, gray, or cream-colored, soft to hard limestone and dolomitic limestone interlayered with the brown dolomite. Although dolomitization has altered or destroyed many of its fossils, the formation is generally fossiliferous and carries a distinctive assemblage of "cone type" Foraminifera. The Avon Park is thinnest beneath the crest and flank of the Ocala uplift in southwestern Alachua County where it is nearest the surface. At wells 936-236-1 and 938-236-3, near Newberry in southwestern Alachua County, the Avon Park has thicknesses of 100 and 110 feet, respectively. At test well 007-222-1, in Union County, the Avon Park is 143 feet thick. The Avon Park is about 210 feet thick at Gainesville and probably maintains a nearly equivalent thickness in most other parts of the four counties. The geologic sections (fig. 5, 6, 7, 8, 9) show wells (in addition to the above) that have penetrated as much as 140 feet of the formation.
Limestones of the Ocala Group have been subdivided and renamed several times in recent years by different investigators. The most recent classification is that of Puri (1957) of the Florida Geological Survey, who divided the Ocala Group from oldest to youngest, into the Inglis, Williston, and Crystal River Formations. These formations are undifferentiated in this report. Limestones of the Ocala Group, the oldest exposed rocks in the area, are at the surface in southern and western Alachua County (fig. 4), but they dip beneath younger formations in other parts of Alachua County and in Bradford, Clay and Union counties. The Ocala Group unconformably overlies the Avon Park limestone.
A limestone plain was formed where the Ocala Group is at the surface. In the outcrop of the Ocala Group (fig. 4), the limestone in most places is covered by a veneer of loose sands of older Pleistocene terrace deposits. In a few places, however, the outcrop of Ocala Group is covered by clayey sands and sandy clays, which are a residuum of the younger Hawthorn and Alachua Formations. The younger sediments over the limestone tend to mask irregularities in the highly eroded surface of the Ocala Group. A karst topography-which includes such features as filled and open sinks, sinkhole lakes, solution pipes, basins, and prairies-is typical of areas underlain by the Ocala Group.
The upper part of the Ocala Group is mostly a soft, white to cream-colored, chalky, coquina limestone. The Ocala Group,




20 FLORIDA GEOLOGICAL SURVEY
though it is in part a coquina throughout its thickness, grades downward into alternating layers of hard and soft, tan to brown, crystalline limestone and dolomitic limestone. Younger materials consisting of sand, clay, and vertebrate fossils have filled sinks, solution pipes, and depressions in the Ocala Group. In the outcrop of the Ocala in Alachua County, sink-fill material was penetrated by well 937-223-1 to a depth of about 200 feet, which is the approximate depth to the base of the Ocala Group and by well 938-234-1 to a depth of at least 268 feet, which would be in the Avon Park Limestone. In southwestern Clay County where the Ocala Group is beneath younger sediments, well 947-202-13, apparently penetrated a deep filled sink which was caused by a collapse of limestones of Eocene age. The Ocala Group was penetrated at a depth of 420 feet, whereas, the Ocala Group would normally be penetrated at a depth of about 200 feet. Boulders and irregular masses of chert or flint are common near the top of the Ocala Group. Cavities up to 3 feet in depth are common and some cavities as much as 40 feet in depth in the limestone in western Alachua County have been reported by drillers.
The Ocala Group is thinnest beneath the crest and flank of the Ocala uplift in southwestern Alachua County. At wells 936-236-1 and 938-236-3 near Newberry, the Ocala Group is 80 and 130 feet thick, respectively. In other parts of the four counties, the Ocala Group ranges in thickness from about 200 to 250 feet. In Alachua County, the Ocala Group is as much as 220 feet thick, and in Clay County the maximum thickness was logged 230 feet in well 958139-1 at Green Cove Springs, but it may be slightly thicker in the northeastern part of Clay County. The Ocala is estimated to be 230 feet thick at Starke in Bradford County, and it may be as much as 250 feet thick northwest of Starke and westward to the vicinity of well 958-217-1. At test well 007-222-1 in Union County, the Ocala was 245 feet thick and drillers' logs of wells at Raiford in eastern Union County indicate an equivalent thickness in this area.
OLIGOCENE SERIES
Some boulders of the Suwannee Limestone of Oligocene age were identified at the surface in western Alachua County but it was not determined if the boulders were in place. The Suwannee is in the subsurface north and northeast of Gainesville in Alachua County, in places in northwestern Alachua County, in the approximate western one-fourth of Bradford County, and in most of Union County west of Lake Butler. Available well data indicate that the




REPORT OF INVESTIGATIONS NO. 35 21
Suwannee is absent in most other parts of these counties and that the formation is entirely absent in Clay County. The locations of wells penetrating the Suwannee that were used to prepare acontour map of the top of the Floridan aquifer are shown in figure 78. The Suwannee Limestone is a residual material, and it probably occurs only locally except in extreme northwestern Alachua County and in western Union County where it seems to be continuous in subsurface.
Owing to the lithologic similarity between the Suwannee Limestone and limestones of the underlying Ocala Group, a separation of these two units is often difficult except where diagnostic fossils occur. The Suwannee is usually identified by its "cone type" foraminifers. Generally, the formation is composed of hard and soft beds of white, tan or cream-colored limestone that is dolomitic and coquinoid in part. Also, some sand and silicified layers of chert and flint are present. North and northeast of Gainesville in Alachua County the Suwannee ranges in thickness from about 30 to 50 feet, and in western Union County and southwestern Bradford County it generally ranges in thickness from 20 to 40 feet. In northwestern Alachua and extreme southern Union counties the formation probably ranges in thickness from 20 to 30 feet.
MIOCENE SERIES
The Hawthorn Formation, a marine deposit of Miocene age, underlies the four counties except in parts of southern and western Alachua County. The Hawthorn crops out in Alachua County in an isolated area around Micanopy and in an irregular pattern extending from Lochloosa Lake northwestward into northwestern and north-central Alachua County. The formation also crops out in southern Union County and southwestern Bradford County (fig. 4). The main body of the outcrop of the formation terminates in Alachua County along a line of low southwestward-facing hills along the edge of the plain formed by limestones of the Ocala Group. Remnants of the Hawthorn, however, have filled sinks and formed a thin mantle of sediment over the outcrop of the Ocala Group (fig. 4). Much of the outcrop of the Hawthorn Formation is in an area of relatively rugged hill and valley terrain, but in some of the area the surface is gently rolling. Most of the Hawthorn outcrop is covered by a veneer of loose sands of the older Pleistocene terrace deposits. The Hawthorn Formation overlies the Ocala Group and the Suwannee Limestone.
The Hawthorn consists chiefly of thick clays and sandy clays




22 FLORIDA GEOLOGICAL SURVEY
that range in color from green to yellow and from gray to blue. Layers or lenses of sand and relatively soft white to gray limestone and sandy phosphatic limestone are interbedded with the clays. Although pebbles and grains of phosphate having a tan, amber, brown, or black color are usually -disseminated throughout the formation, the pebbles and grains of phosphate seem to be concentrated at various levels. The lower part of the Hawthorn contains beds of tan, gray, and grayish-green, dense, hard limestone and dolomitic limestone, and interlayered clays. These beds occur in approximately the eastern one-fourth of Alachua County, all of Bradford County except the extreme southwestern part including Brooker, that part of Union County lying generally east of Lake Butler, and all of Clay County. In Alachua County, the basal limestones and clays are usually 15 to 20 feet thick; whereas in Bradford, Clay and Union counties the basal limestones are from 20 to 30 feet thick except in places in eastern Clay County where they are about 35 feet thick.
The Hawthorn Formation ranges in thickness in Alachua County from a few feet where its outcrop merges with the Ocala outcrop to about 200 feet in the northeastern part of the county (sections A-A', D-D' in fig. 5, 8). The Hawthorn is as much as 160 feet thick in the vicinity of Gainesville. In most other parts of Alachua County the formation is from 60 to 120 feet thick except in the outcrop in the Micanopy area where its thickness probably does not exceed 50 feet. In Union County, west of Lake Butler, the Hawthorn is from 55 to 100 feet thick; but east of Lake Butler it apparently is thicker because 265 feet of Hawthorn was penetrated by well 004-211-3 at Raiford State Prison in extreme eastern Union_County. In southern Bradford County, at Brooker, only 85 feet of the Hawthorn was penetrated by well 953-220-2, but in southeastern Bradford County 160 feet of Hawthorn was penetrated by test well 952-204-1. At Starke and in most of central Bradford County the formation is about 200 feet thick, but close to New River and in the northern part of Bradford County it is 225 to 250 feet thick. In Clay County along the lines of sections A-A', B-B', and E-E' (fig. 5, 6, 9), the thickness ranges from 80 feet at well 943-202-3 in the extreme southwestern part of Clay County to 235 feet at well 958-159-1 near Kingsley Lake in west-central Clay County. In southwestern Clay County the Hawthorn, as shown by cuttings from scattered wells, has a maximum thickness of about 160 feet. Drillers logs show that the formation is as much as 250 feet thick at places in central and northeastern Clay County.




REPORT OF INVESTIGATIONS No. 35 23
The relatively thick and impermeable Hawthorn sediments are the principal confining beds that confine water under artesian pressure in the Floridan aquifer.
The Hawthorn Formation is exposed in open sinks such as the Devil's Mill Hopper near Gainesville in Alachua County and Brooks Sink near Brooker in Bradford County. In the Devil's Mill Hopper at least 115 feet of Hawthorn sediments are exposed (Cooke and Mossom 1929, p. 129).
Beds of late Miocene age that crop out along the north and south forks of Black Creek in north-central Clay County (fig. 4) are referred to as the Choctawhatchee Formation in this report. The outcrop of the Choctawhatchee is covered in most places by a thin mantle of sediment of Pleistocene and Recent age. The Choctawhatchee, which overlies the Hawthorn Formation, dips beneath younger beds away from its outcrop. It is apparently continuous in the subsurface in most of Bradford County except for that part generally west and southwest of Starke and Hampton, most of Union County except south and west of test well 001-224-1, most, if not all, of Clay County, and a part of eastern Alachua County.
The Choctawhatchee Formation consists mostly of yellow and cream-colored, soft, fossiliferous clay and partly indurated marl. Thin beds of sand and thin beds of limestone are interlayered with the clay and marl, and grains and pebbles of phosphate and silica are disseminated in the beds. Owing to the abundant shell (mollusks) content in some areas the name "shell marl" has been
-applied to the Choctawhatchee Formation. Drill cuttings examined from representative wells show that in most areas in the four counties the shells are few in number and are only poorly preserved fragments, molds, or casts. However, the cuttings from some wells in eastern Clay County, show concentrations of well-preserved shells. The Choctawhatchee generally is 10 to 30 feet thick in the four counties. However, along geologic section A-A' (fig. 5) the formation is as much as 40 feet thick in east-central Bradford County and central Clay County.
MIOCENE TO PLEISTOCENE (?) SERIES
The Alachua Formation of Miocene to Pleistocene age is exposed in southwestern Alachua County where it forms low rolling sandhills over the eroded crest of the Ocala uplift (fig. 4). The formation consists, in part if not entirely, of terrestrial deposits, which in some places contain land-vertebrate fossils of various




24 FLORIDA GEOLOGICAL SURVEY
types. The Alachua, whose surface is covered in most places by a veneer of loose sands that presumably are older Pleistocene (?) terrace deposits, lies on the highly eroded surface of the Ocala Group.
Sand is one of the principal components of the formation and, where the Alachua sediments are exposed in quarries, the sand is generally in the upper part of the formation. The sand is white, gray or buff except where it has been exposed and has weathered to various shades of red. Interbedded with and commonly underlying the sands are varicolored clays, sandy clays, clayey sands, and disseminated grains and pebbles of phosphate. Clays and associated vertebrate fossils of the Alachua have accumulated in many of the sinks and depressions in the underlying limestone. Siliceous limestone and flint and phosphate boulders are scattered throughout the formation. Boulders and plates of hard rock phosphate in the Alachua Formation have been quarried extensively in southwestern Alachua County. The Alachua Formation ranges in thickness from 25 to 35 feet as indicated by well logs and quarry exposures.
PLEISTOCENE SERIES
Clastic sediments in_ Clay and Bradford counties that in most geologic references are placed in the Citronelle Formation of Pliocene age have recently been tentatively reclassified by the Florida Geological Survey. Puri and Vernon (1959, p. 128-129) of the Florida Geological Survey have referred to these sediments as "Unnamed coarse clastics" and have assigned them to the Pleistocene Series pending further studies by the Florida Geological Survey. These studies are expected to provide a formational name for these beds and to establish their exact stratigraphic position. The tentative nomenclature and age assigned to these beds by the Florida Geological Survey are followed in this report.
The unnamed coarse clastics are exposed in southwestern Clay and southeastern Bradford counties (fig. 4). Nearly all the outcrop of the formation is covered by a veneer of sands of older Pleistocene terrace deposits. The veneer ranges in thickness from 0 to 15 feet except north of the 29050' parallel where locally it may be thicker. At the edge of the outcrop, the unnamed coarse clastics terminate abruptly or thin to extinction beneath the younger formations within a short distance. The outcrop of the deposits is in hills and lakes except where the overlying veneer of older Pleistocene terrace deposits is gently rolling. The unnamed coarse plastics overlie the Choctawhatchee Formation.




REPORT OF INVESTIGATIONS No. 35 25
The unnamed coarse plastics are a nonfossiliferous deltaic deposit that is composed mostly of varicolored sand and clayey sand that contains quartz gravels locally. Clay or kaolin that acts as a binder is disseminated in the sands or is in thin beds. In the vicinity of Brooklyn Lake, test wells penetrated as much as 16 feet of red and yellow sandy clay in the upper part of the formation overlying the varicolored sand and clayey sand. In most of the outcrop north of Brooklyn Lake the red and yellow sediments seem to be absent and in other parts of the outcrop the sediments, where present, are chiefly clayey sands. The unnamed coarse plastics are estimated to have maximum thickness of 90 feet where the deposit underlies the higher parts of Trail Ridge, but elsewhere in its outcrop the thickness probably does hot exceed 70 feet. In southwestern Clay County, the formation ranged in thickness from 22 feet at test well 945-201-2 to 67 feet at test well 948-202-4. Outside of the outcrop of the unnamed coarse clastics (fig. 4) the maximum thickness of the formation penetrated was 46 feet at test well 943-202-3.
Several higher terraces, which are marine sediments that were deposited during the early interglacial stages of the Pleistocene Epoch, compose the older Pleistocene terrace deposits of this report. Cooke (1945, p. 273-281) defined these higher terraces as "Early SPleistocene Deposits" but Puri and Vernon (1959, p. 239-240) include the higher terraces with several lower (younger) terraces in the Pleistocene and Recent Series. No attempt was made to separate the higher (early) Pleistocene deposits (terraces) that are described by Cooke. The older Pleistocene terrace deposits are exposed in central and eastern Alachua County and also crop out in most of Bradford and Union counties and in western Clay County (fig. 4). The deposits overlie the Hawthorn and Choctawhatchee Formations and the unnamed coarse plastics. Older Pleistocene terrace deposits, consisting mostly of loose tan, yellow, and gray sands that range in thickness up to 15 feet, cover the older formations (except the Choctawhatchee Formation) as shown in figure 4, but the loose sands were not mapped.
The older Pleistocene terrace -deposits may be divided into two lithologic units-one predominantly sand and one predominantly clay. The predominantly sand unit generally grades downward into clayey sands and is the predominant material in the nearly enclosed outcrop in central and southeastern Alachua County and eastern Bradford and western Clay counties. These sands are usually dark gray, brown, or black due- to organic matter and iron-bearing compounds, but they may be tan, yellow, or various shades of gray




26 FLORIDA GEOLOGICAL SURVEY
where they have been exposed. At a few places in the vicinity of Gainesville the loose tan, yellow, and gray sands compose the entire deposit but north of Gainesville these loose sands generally are in the upper few feet of the beds above the darker colored clayey sands. In Alachua County the composite thickness of these beds ranges from about 20 to 45 feet. In eastern Bradford and western Clay counties, the sands are 80 to 100 feet thick except beneath the higher land surfaces where the maximum thickness is about 140 feet.
The predominantly clay unit consists of mottled red, yellow, and gray clay and sandy clay, which is exposed in many places in Alachua, Bradford, and Union counties. It is in the upper part of a sequence of beds that is different from those already described and was the basis for mapping the older Pleistocene terrace deposits in other parts of the outcrop that are not described above. These mottled beds are mostly clay and sandy clay that range in thickness from about 5 to 12 feet. They overlie tan, cream-colored, and pink sands and clayey sands that contain layers of sandy clay and are covered by a veneer of loose tan, yellow, gray, and white sand, which is from 1 to 5 feet thick. The thickness of the composite of these sediments is generally 40 feet or less but the beds are as much as 50 feet thick in places. The sequence of beds, which includes the mottled red, yellow, and gray sediments, is interspersed with the predominant sand lithology in the outcrop in central Alachua County, but in no particular pattern.
Puri and Vernon (1959, p. 128) have included a part of the older Pleistocene terrace deposits-that is, exposures at the Gainesville airport of mottled sandy clay and clayey sand-under a description of the unnamed coarse clastics. Studies currently (1961) being made by the Florida Geological Survey are expected to define more accurately the stratigraphic position and relationship of the sediments included here as the older Pleistocene terrace deposits and of the Pleistocene deposits in Florida.
PLEISTOCENE AND RECENT SERIES
Several lower terraces formed during the later interglacial stages of the Pleistocene Epoch are the younger marine and estuarine terrace deposits of Pleistocene and Recent age. The several lower terraces in Clay County named and referred to by Cooke (1945, p. 281-311) as "Late Pleistocene deposits" are undifferentiated in this report. The Pleistocene and Recent deposits




REPORT OF INVESTIGATIONS NO. 35 27
are exposed over parts of western and all of eastern Clay County as a series of terraces or plains that drop successively lower eastward to the St. Johns River (fig. 4). These deposits overlie the Choctawhatchee Formation and unnamed coarse clastics and overlap the older Pleistocene terrace deposits along their contact in western Clay County. Sediments of Pleistocene and Recent age that blanket the outcrop of the Choctawhatchee Formation to depths ranging up to about 15 feet were not mapped.
The Pleistocene and Recent deposits are composed chiefly of sands and clayey sands that probably contain many layers of clay, marl, and sandy clay. The sands, clays, and marls are generally dark gray, brown or black because of ferruginous minerals, disseminated organic matter, and layers of peat and muck. Beds of shell and shell marl that lie above the Choctawhatchee Formation at some places in Clay County are tentatively included as part of the Pleistocene and Recent deposits because of their stratigraphic position. Drill cuttings from s6me wells in the vicinity of Green Cove Springs in eastern Clay County indicate a concentration of shells at places in this area; but in drill cuttings from wells at Orange Park and from test well 952-147-2 south of Penney Farms, the shells are intermixed with clayey materials as a shell marl. The Pleistocene and Recent deposits average about 60 feet in thickness, but the deposits are as much as 80 feet in thickness in areas of high elevation.
STRUCTURE
The principal geologic structure of the area is the Ocala uplift, an anticlinal fold or arch whose crest transverses southwestern Alachua County. The folding has arched beds of Tertiary age and has brought limestones of the Ocala Group to the surface or close to the surface along the crest and flank of the uplift. The main axis of the uplift lies several miles west of Alachua County and, in general, parallels the north-south axis of the Florida Peninsula. Geologic sections A-A', B-B', C-C', D-D', and E-E' (fig. 5, 6, 7, 8, 9) extend across parts of Alachua, Bradford, Clay, and Union counties in directions generally parallel or perpendicular to the axis of the uplift. A structure contour map (fig. 4), which may be used to determine the approximate depth to the top of the Ocala Group, shows the configuration and elevation of the top of the Ocala Group. The eroded and flattened crest of the Ocala uplift lies west of the +40-foot contour (fig. 4) in southwestern Alachua County.




28 FLORIDA GEOLOGICAL SURVEY
The regional dip of the Tertiary beds on the flank of the uplift is east-northeast and averages about 6 feet per mile. Locally, however, the dip may be greater on the flanks or limbs of smaller or lesser folds on the flank of the uplift or along zones of faulting. At some places the dip of the strata decreases to form structural terraces, and where the terraces have a local dip the structure is a monocline (fig. 5).
The contour map and the geologic sections show several lesser folds on the flank of the uplift that were formed probably by the same structural forces that caused the Ocala uplift. The most prominent of these lesser folds is one whose crest is in northeastern Alachua County in a triangle defined by Waldo, Melrose, and Hawthorn. The configuration of the surface of the limestone indicates that the structure is a double plunging fold that plunges to the northwest and southeast. Such buried folds or structural "highs" often have topographic expression at a land surface, forming a hill or region of relatively great relief. This fold, whose crest is at an elevation of at least 50 feet above msl, passes west and southwest for a distance of about 5 miles into a downwarp or basin-like structure whose trough is more than 130 feet lower. The northeastern flank of the fold passes into the downwarp or similar proportions in southwestern Clay County but the structure here is made more complicated by other factors.
In the lake region of southwestern Clay County, as in other parts of the four counties, the structural forces that caused the folding doubtless also brought about some faulting or fracturing of the rocks. In southwestern Clay County the relatively great variation in the elevation of the top of limestones of the Ocala Group within short distances (fig. 4) is attributed in part to a slumping of the beds due to solution. The structure may also be interpreted as representing small, tight folds with steeply dipping limbs or the displacement of beds by faulting or fracturing.
CLIMATE
TEMPERATURE
According to the records of the U. S. Weather Bureau, the average temperature at Gainesville is 70'F. Figure 10 shows, for the 49-year period 1912-60, the average of the monthly meah temperatures, the highest monthly mean temperature, and the lowest monthly mean temperature. The graph also shows the




a
REPORT OF INVESTIGATIONS No. 35 29
00
60
EXPLANATION
maximum C
50
I-I
E maximum
30
200
Ja dn Feb Mar Apr May June July Aug Sept Oct Nov Dec
Figure 10. Monthly mean temperatures, 1912-60, at Gainesville, Florida.
average of the daily maximum and the average of the daily
40 E
minimum temperature for each month in 1960.
"6 minimum
average of th--l axmmadth vrg o h al
The average of the monthly mean temperatures ranged from 58.60F in December to 81.30F in August. The winter temperatures are more erratic than the summer temperatures. In other words, in the winter the area has periods of balmy weather followed by short periods of freezing temperature.
The difference between the average of the daily maximum and average of the daily minimum temperature in 1960 ranged from 20 to 280F. Only rarely does the temperature reach 1000F and only occasionally does it drop into the teens. In fact, 280 frostfree days can be expected annually.




30 FLORIDA GEOLjGICAL SURVEY
RAINFALL
Rainfall in the area is quite varied in both annual amounts and seasonal distribution. Figure 11 shows the variations in yearly amounts, the monthly minimums, the monthly averages, and the monthly maximums at Gainesville for the period 1900-60. The total annual rainfall at Gainesville for the period 1900-60 ranged from 32.79 to 73.30 inches. In an average year the dry season is from late October through May, the driest month being November. Monthly total rainfall varied from none in March to 19.9 inches in September. On the average the area receives over half of its annual rainfall during the 4-month period June through September.
22
Figure 11. Rainfall at Gainesville, Fla. for the period 1900-60.
An outstanding feature of the rainfall regime is the rather abrupt start of the rainy season; the average rainfall of June is about double that of May. The rainy season at times extends into October, but the latter part of October is usually dry.
The area's rainfall occurs as two general types (1) summer rainfall which is mostly shower and thundershower activity; and
(2) winter and early spring rainfall which is more the widespread general type associated with frontal activity. Most of the rain in the summer is in the form of local showers and thundershowers. It is not uncommon for 100 thundershowers per year to occur in the area. Although these thundershowers are usually of short duration, relatively large amounts of rain fall. Rainfalls in excess of 6 inches have been observed during a 6-hour period.
Because most of the summer showers are local, large differences in monthly and annual totals occur during the same periods at




REPORT OF INVESTIGATIONS NO. 35 31
different points in the area. To a large extent, however, these differences are minimized when a comparison of long-term averages is made; the maximum difference in the long-term average at three stations-Raiford, Federal Point, and Gainesville-is less than
3 inches. The average annual rainfall in the area is 52.0 inches.
Extreme variations in annual rainfall totals can occur in consecutive years-the year 1953 ranks among the wettest since 1900, while 1954 ranks among the driest of record. (Dry periods are defined as those having below average rainfall and wet periods as those having above average rainfall.) Periods of several wet years or several dry years also can occur in succession. The period of 1944-49 is the wettest of record in the area, and 1954-56 is the driest. Table 2 shows the total departure from average rainfall for several periods of extreme rainfall conditions at Gainesville.
TABLE 2. Departure from Average Rainfall, in Inches, At Gainesville, Florida.
Period Dry periods Wet periods
1906-11 (6 years) -44.01 1914-18 (5 years) -33.72
1928-30 (3 years) +18.24
1931-34 (4 years) -25.20
1944-49 (6 years) +45.87
1954-56 (3 years) -22.66
SURFACE WATER
Surface water is defined as water that can be seen on the surface of the ground, such as that in lakes, streams, canals, springs and that stored temporarily in other land depressions. In many instances surface water and ground water are closely related. Many surface-water bodies receive large quantities of water from the ground; fdr example, springs have direct connections with groundwater reservoirs. Streams and lakes can either gain or lose water by way of the ground. The relation of surface water and ground water is sometimes intricate. A lake can gain water from the water-table aquifer at certain stages and lose water to the watertable aquifer at other stages; or, gain water from the water-table aquifer and at the same time lose water directly to the deeper ground-water aquifer, if a lake bottom is penetrated by a sinkhole.




TAII, 3, Location Of uGaging Stations, Types of Surface Water Data Collected And Periods of Records,
Site Drainage No, Name and location (s, m.) Type and period of record
1 Ates Creek near Penney Farms, Fla. 40.8 Periodic discharge, crest stages, 1057-60
2 Blue Pond near Keystone Heights, Fla. .81 Depth, stage, 1058.60 3 Brooklyn Lake at Keystone Heights, Fla. 1.00 Depth, stage, 1057-60
4 Brooklyn Lake outlet at Keystone Heights, Fla. 17.4 Occasional discharge, 1950-00
5 Bull Creek near Middleburg, Fla. 20.4 Occasional discharge, crest stages, 1057-60 6 Butler Creek near Lake Butler, Fla. 8 Occasional discharge, crest stages, 1957-00
7 Camps Canal near Rochelle, Fla. 115 Periodic discharge, 1048-52; daily stage and discharge, 1957-60
8 Clarkes Creek near Green Cove Springs, Fla. 8,8 Occasional discharge, crest stages, 1057-60
9 Cross Creek near Island Grove, FIa ........ Occasional discharge, 1942-47 10 Deep Creek near Rodman, Fla. 54.3 Occasional discharge, crest stage, 1956-60 11 Etonia Creek near Florahome, Fla. 172 Daily stage and discharge, 1949-51 12 Glen Springs near Gainesville, Fla. ........ Occasional discharge, 1942-60 18 Governors Creek at State Road 10 near Green Cove
Springs, Fla. 10.5 Occasional discharge, 1050 14 Green Cove Springs at Green Cove Springs, Fla. ........ Occasional discharge, 1020-60 15 Greens Creek near Penney Farms, Fla. 14.0 Periodic discharge, peak stags, 1957-60 16 Hatchet Creek near Gainesville, Fla. 57 Occasional discharge, peak stage 1948-60 17 Hellbronn Springs 6 mi, N.W. of Starke, Fla. ....... Occasional discharge, 1946-60
18 Hogtown Creek near Gainesville, Fla. 15.6 Occasional discharge, peak stage, 1958-60 19 Kingsley Lake ati Camp Blanding, Fla. 2.54 Depth, stage, 1945, 1947-60 20 Lake Butler at Lake Butler, Fla. ,4 Stage, 1957-60 21 Lake Geneva at Keystone Heights, Fla. 2.73 Depth, stage, 1957-60




22 Lake Grandin near Interlachen, Fla., .55 Stage, 1957-60 28 Lake Johnson near Keystone Heights, Fla. .74 Stage, 1945-60 24 Lake Sampson near Starke, Fla. 8.24 Stage, 1957-60 25 Little Hatchet Creek near Gainesville, Fl. 10.9 Occasional discharge, 1947, 1956 26 Little Orange Creek near Orange Springs,, Fla. 78.9 Periodic discharge, 1947-52; occasional discharge, 1956 27 Loch Lommond near Keystone Heights, Fla. ........ Depth, stage, 1959-60 28 'Lochloosa Creek at Grove Park, Fla. 84.7 Occasional discharge, 1947, 1956; periodic discharge, 1957-60 29 Lochloosa Creek near Hawthorne, Fla. 48.8 Periodic discharge, 1947-52o 80 Lochloosa Lake at Lochloosa, Fla. *10.8 Stage, 1942-52, 1956-60 81 Lochloosa Lake Outlet near Lochloosa, Fla. .... Daily stage and discharge, 1946-55 0 32 Magnesia Springs near Hawthorne, Fla. ..... Occasional discharge, 1941-60 88 Magnolia Lake near Keystone Heights, Fla. .81 Depth, stage, 1958-60 84 Magnolia Lake Outlet near Keystone Heights, Fla. 14.8 Occasional discharge, 1956-60 85 Newnans Lake near Gainesville, Fla. 8.2 Stage, 1945-52, 1957-60 86 New River near Lake Butler, Fla. 212 Daily stage and discharge, 1950-60 37 New River near Raiford, Fla. 98.8 Occasional discharge, 1957-60 O 88 North Fork Black Creek above Boggy Branch 84.1 Occasional discharge, 1958-60 89 North Fork Black Creek near Highlands, Fla. 48.9 Daily stage and discharge, 1957-60 40 North Fork Black Greek near Middleburg, Fla. 174 Daily stage and discharge, 1931-60 41 North Fork Black Creek at State Road 16, Fla. 9,7 Occasional discharge, 1956 42 Olustee Creek at Providence, Fla. 150 Daily stage and discharge, 1957-60 48 Orange Greek at Orange Springs, Fla. 481 Daily stage and discharge, 1942-52, 1955-60 44 Orange Lake at Orange Lake, Fla. *26.7 Stage, 1945-60 45 Orange Lake Outlet near Citra, Fla. .... Daily stage and discharge, 1946-55 46 Ortega Creek near Jacksonville, Fla. 27.8 Occasional discharge, 1956-60 47 Pebble Lake near Keystone Heights, Fla. .01 Stage, 1945-50, 1952-58, 1954-60




site airena
N' Nae and location (, ill.) Type and period of recuird
48 l'Poe Springs near fligh Springs, Flia. ..... Occasional discharge, 1020-60 49 Prairie Creek at State lRoad 20 near (Jaineasville, l'Il. Ill Oceasulonail discharge, 1047, 1948, 1)5(6 50 River Styx near Micanopy, Fla. ........ Occasional dischurge, 1)5(1-58 51 Sampson River at Sampson, Fla. (17,8 Occasional discharge, 1057-10 52 Sand Hill Lake near Keystone Heights, Fla. 1.05 Depth, stage. 1957-60 53 Santa Fe Lake near Keystone Heights, Fla. 8.05 Stage, 11)57-60 54 Santa Fe River near Fort White, Fla. 1,080 Daily stage and discharge, 1927-20, 1032-600 55 Santa Fe River near Graham, Fla. 135 Dally stage and discharge, 1057.60 56 Santa Fe River near High Springs, Fla. 950 Daily stage and discharge, 1931-60 57 Santa Fe River at O'leno State Park, Fla. ........ Occasional discharge, 1961 58 Santa Fe River at State Road 235 at Brooker, Fla. 245 Occasional discharge, 10560 59 Santa Fe River at State Road 241 near Worthington, Fla. 670 Occasional discharge, 1956 60 Santa Fe River at U. S. Highway 301 near
Hampton, Fla. 115 Occasional discharge, 1956
61 Santa Fe River at Worthington, Fla, 630 Daily stage and discharge, 1981-60 62 South Fork Black Creek near Camp Blanding, Fla, 34.8 Daily stage and discharge, 1957-60 68 South Fork Black Creek near Penney Farms, Fla. 184 Daily stage and discharge, 19839-60 614 Swift Creek near Lake Butler, Fla. 27 Daily stage and discharge, 1957-60 65 Wadesboro Spring near Orange Park, Fla. ........ Occasional discharge, 1946.60 66 Water Oak Creek near Starke, Fla. 20.7 Occasional discharge. 1957-60 67 Whitmore Lake at Camp Blanding. Fla. ........ Depth, 1960 68 Worthington Springs at Worthington, Fla. ........ Occasional discharge, 1946-60 69 Yellow Water Creek at Duval-Clay Line, Fla. 61,2 Occasional discharge, 1956 70 Yellow Water Creek near Maxville, Fla. 25.7 Periodic discharge, crest stages, 1957-60
*Area of lake surface




REPORT OF INVESTIGATIONS No. 35 35
The extent to which this relationship affects a surface-water body depends on the rate of exchange. Each body of water has individual behavior characteristics. Rainfall is the only factor common to all water bodies that contributes to these characteristics.
Most surface-water problems can be attributed to the uneven distribution of rainfall. Floods and droughts occur in unpredictable cycles that follow very closely periods of high and low rainfall. At present (1961) there is no practical method of modifying or controlling rainfall. Therefore, problems associated with floods and droughts have to be dealt with by a system of lake and stream controls.
Three useful figures expressing streamflow are: figures of average flow, minimum flow, and maximum flow. The average flow of a stream is an indication of its normal flow and also serves as a guide in determining the quantity of water that is available over a long period of time from a system having dams and storage reservoirs.
Minimum flow is the limiting factor in the ultimate use of a stream not having dams and storage reservoirs. Information on maximum flows is important not only in planning the use of a stream but also in determining the use of land adjoining the flood plain and in the design of river appurtenances such as bridges. Magnitudes, durations, and frequencies of low flows and high flows are useful in planning the full use of a stream. If a damaging flood or drought is of short duration and occurs at infrequent intervals, it might be economically feasible to withstand the resultant damage.
Data collected at a stream-gaging station or sampling site are for a point on the stream and represent a composite of conditions in the basin above that point. Data at any other point can be estimated on the basis of station records. Table 3 gives the locations of gaging stations and types of surface-water data collected within the four counties. Topography and geology are also important factors governing the behavior of a water body. By applying hydrologic principles to these types of data, characteristics of the water resources of an area can be determined. This section of the report will answer many questions of this nature on the surface-water resources of Alachua, Bradford, Clay, and Union counties.
The average streamflow from the four counties is approximately 1,150 mgd, excluding the flow of the St. Johns River. The average streamflow from Union and Bradford counties and the northern half of Alachua County which leaves the area by way of the Santa




36 FLORIDA GEOLOGICAL SURVEY
Fe River is about 710 mgd. On the average, about 97 mgd flow from southeastern Alachua County through Orange Creek. The average flow from Clay County is about 342 mgd through Black Creek and small streams draining into St. Johns River from the eastern edge of the county. The flow chart in figure 12 shows the average flow of major streams in the area. Average yearly streamflows have been as little as one-third the average flows for the periods of record and as much as 21/2 times the average flows for the p ridds of record.
The St. Johns River is the largest source of surface water within the four counties. It flows north along the eastern boundary of Clay County and drains about 7,000 square miles upstream from Green Cove Springs. At that point its average flow is about 4,500 mgd. The river is large enough to harbor a Navy base at Green Cove Springs.
The average runoff from the area is about 12 inches per year, which is less than one-fourth the average rainfall. The average yearly rainfall is 52 inches. The portion of rainfall not accounted
"N>
N
-V
Figure 12. Flow chart showing average flow of streams in Alachua, Bradford, Clay, and Union counties, Florida.




REPORT OF INVESTIGATIONS NO. 35 37
for as surface runoff is taken up by evaporation, transpiration, and ground-water outflow.
An area of about 300 square miles in southwestern Alachua County has no surface outflow. The few small streams in that area terminate in sinkholes. Most of the rainfall on that area leaves as underground flow.
There are more than 50 lakes in the four counties that exceed 0.02 square mile in size, the largest of which is 25.7 square miles in size. The combined surface area of all these lakes is about 90 square miles or more than 4 percent of the total landai~ea. These lakes range in elevation from 57 feet above sea level for the lowest to 176 feet above sea level for the highest. The ranges of fluctuation in stage of these lakes are quite varied. Some of the lakes have only minor seasonal fluctuations in stage, as little as 3.5 feet, and others have varied in stage as much as 32 feet. The greatest known lake depth is 85 feet.
ST. JOHNS RIVER
The St. Johns River flows northward 250 miles from its origin in Indian River County to Jacksonville, then eastward for 25 miles to the Atlantic. It is the largest and longest river wholly within the state, and it is the third largest in the state in terms of average flow. Its drainage area is 8,000 square miles.
The slope of the river is exceedingly mild. The maximum fall during floods is only 27 feet throughout the total length of 275 miles. The river flow is affected by ocean tides as far upstream as Lake George, 120 miles from the mouth, and even farther during periods of low river stages and high tides. The normal tide range at Jacksonville is about 2.0 feet and is only slightly less at Green Cove Springs in Clay County, 50 miles from the mouth of the river.
The St. Johns River forms the eastern boundary of Clay County. The river in this vicinity is the collecting channel for all surface flow from Clay County and is from 1 to 3 miles wide.
The flow of the St. Johns River at Green Cove Springs is estimated to be 4,500 mgd. At DeLand, 85 miles farther upstream, the average flow is 2,000 mgd. Although not a common occurrence, a reverse flow-that is, flow in an upstream direction-at the rate of 1,000 mgd has been measured at DeLand. The flow at Jacksonville reverses direction with each change of tide.




38 FLORIDA GEOLOGICAL SURVEY
BLACK CREEK BASIN
Black Creek, a tributary to the St. Johns River, has a drainage area of 474 square miles. About 400 of the 598 square miles composing Clay County are drained by Black Creek. The only major part of the basin lying outside the county is the upper 74 square miles of Yellow Water Creek, a tributary from the north. The basin is about 16 miles wide and 30 miles long, the long axis lying in a north-south direction. The basin is outlined in figure 13. The
BLACK CREEK BASIN
r
1/
I 46
N
=" / ". ..M DDLEBURG mass
IV- -)' f-- -- .65
Figure 13. Drainage map of the Black Creek basin showing data-collection
sites.
I j '~N MIDOLEBUAG _____BOW~
GREEN COVE '
WAM I SPRINGS
ra e r t., S. n u b e oare 3
Figure 13. Drainage map of the Black Creek basin showing data-collection sites.




REPORT OF INVESTIGATIONS NO. 35 39
two major tributaries in the basin, South Fork Black Creek and North Fork Black Creek, join at the town of Middleburg to form Black Creek. The stream then flows eastward and enters the St. Johns River about 3 miles north of Green Cove Springs.
South Fork Black Creek heads in three small lakes in the Camp Blanding Military Reservation which are Stevens Lake, Whitmore Lake, and Varnes Lake. The major tributaries to the South Fork are Ates Creek, Greens Creek, and Bull Creek.
North Fork Black Creek heads in Kingsley Lake, flows northward for about 14 miles where it turns sharply to the southeast. The larger tributaries enter from the west and north; the major tributary is Yellow Water Creek that heads in a high, swampy section of Duval County to the north.
The topography of the basin is hilly with the highest elevation about 250 feet above msl near Kingsley Lake on the western drainage divide and the lowest is less than 5 feet above msl at the St. Johns River. Stream channels have slopes of from 5 to 30 feet per mile except in the lower reaches where the elevations are near sea level. Figure 14 shows channel-bottom profiles of streams in the Black Creek basin. Runoff within the basin varies from area to area. Topography and geology cause these variations. The average rainfall is equal for all areas within the basin. Average runoff in inches per year from areas within the basin is given in figure 15. Some of these figures were computed from short-term records and can be used only as a guide for computing runoff from ungaged areas. Runoff in inches is defined as the depth to which an area would be covered if all the water draining from it were distributed evenly over its surface. The term is used for comparing runoff to rainfall. On the average, the basin reseives 52 inches of rainfall per year. A plot of the annual rainfall at Glen St. Marys against the annual runoff for North Fork Black Creek at Middleburg is shown in figure 16. This plot is only an indication of the rainfall-runoff relation. Much of the scattering of points in this illutration is caused by variations in the amount of antecedent rainfall conditions and by uneven geographic distribution of rainfall. More runoff will result from a rain that falls on an area that is wet from a previous rain than from one that is not.
There are two areas within the basin that have extremely low runoff, the headwaters of Yellow Water Creek and the headwaters of North Fork Black Creek. Yellow Water Creek heads a high, flat, swampy area. Rainon that area stands on the ground surface for long periods and evaporation, transpiration, and seepage take




,4o .. .-- ..- -- go ...... -- -- '0 -J -.... .... -- .... - -- -- -- 880
140 go GO -11g-o0 - - - 0- - - -- 0
to O -0 t 4 ..
u8 0
I8
It0 to- -t IG-O-40 ~ -- --0 4, 4 6
-. -----... I .,
Fl
HN0 4 oM M I
- 1 Cs i -kCebi 30 z14
IIto
-- '" S i 0.. ----' 0
0 s 4 1 to
I L
0 40 .~e~U so--4
04 1 4 4 a
.0e-Dl he ,i e .' o i.E .C 0 M& noe,*~, Apegi
0 a 4 a A 0 I 14 Is Is o 20 2 24 t6 35 SO 3 34 36 35 40 42 44 46 43
CHANNEL OISTAHOC FROM MOUTH, IN MILES
Figure 14. Channel-bottom profiles of streams in the Black Creek basin,




REPORT OF INVESTIGATIONS NO. 35 41
II
5 / \
II I
1% C1
7-\
0 1
Figure 15. Average runoff in inches per year from areas within the Black Creek basin.
a heavy toll of water, which accounts for the low runoff of only
- /
5 inches per year.
The headwater area of North Fork Black Creek, from which
j .1 CF n ~
00 5' 1 .15LES
Figure 15. Average runoff in inches'per year from areas within the Black Creek basin.
a heavy toll of water, which accounts for the low runoff of only
5 inches per year.
The headwater area of North Fork Black Creek, from which the runoff is 7 inches per year as shown in figure 16, covers 9.7 square miles. About one-fourth (2.54 sq. mi.) of the area is occupied by Kingsley Lake. A large part of the potential runoff from this area evaporates from the lake surface.




42 FLORIDA GEOLOGICAL SURVEY
90
En
80
U,
E**
700
o**
z
w
-J
.ee
70
En
6 0 Uf)
. *@
o 60
2
z 0
** 50 U
z 0
40
z
z
30
0 10 20 30 40
ANNUAL RUNOFF, IN INCHES
(NORTH FORK BLACK CREEK AT MIDDLEBURG)
Figure 16. Rainfall-runoff relation.




REPORT OF INVESTIGATIONS No. 35 43
Runoff from the South Fork is slightly higher than that from the North Fork except during extremely wet years. The average runoff from the South Fork is about 16.0 inches per year and from the North Fork, about 13.7 inches per year. In 1955, the driest year since records began in 1932, runoff from South Fork was 5.4 inches and from North Fork, 3.9 inches. In 1948, an extremely wet year, the South Fork runoff was 30.6 inches and the North Fork runoff was 34.4 inches.
Yearly average runoff from the entire basin has varied from 4.6 inches in 1955 to 33 inches in 1948. The average runoff from the basin is estimated to be 14.8 inches per year, which is 28 percent of the average rainfall of 52 inches. The remaining 37.2 inches of rainfall is taken up by evaporation, transpiration, and seepage.
The average flow from the basin is 515 cfs (cubic feet per second) (333 mgd), which is equivalent to 1.08 cfs per square mile of drainage area. The South Fork contributes 225 cfs, or 1.17 cfs per square mile, and the North Fork contributes 200 cfs, or 1.01 cfs per square mile. An average flow of about 90 cfs is contributed by small tributaries below the confluence of North Fork and South Fork.
Flow-duration curves for four stations in the Black Creek basin are shown in figure 17. These curves were developed using periods of records for the Penney Farms, Highland, and Camp Blanding stations, which were extended to cover the period of the Middleburg record, 1932-60. The flow-duration curves show the percent of time a specified discharge has been equaled or exceeded during the period of record. For example, in figure 18 the mean daily flow of North Fork Black Creek near Middleburg equaled or exceeded 6.8 cfs for 99 percent of the time during the period 1932-60 (10,596 days) or, on the average, less than 6.8 cfs occurred 1 percent of the time, or once in 106 days. The flowduration curves do not give any information on the continuous length of time that a specified discharge occurred.
The curves given in figures 18 and 19 show the discharge available without storage for the Penney Farms and Middleburg stations, respectively. The upper curves in these illustrations show the maximum number of consecutive days and months during which the discharge was less than a given amount, and the lower curves show the lowest average discharge for the period indicated. For example, at the Middleburg station, 10 consecutive days was the longest period that the discharge was 5.5 cfs or less, and the




44 FLORIDA GEOLOGICAL SURVEY
o0,00 oO DRAINAGE AREA GAGING STATION SO. MI.
L SOUTH FORK BLACK CREEK
NEAR PENNEY FARMS, FLA. 134 ,00o -- 2. NORTH FORK BLACK CREEK
- 3. SOTH FORK BLACK CREEK NEAR CAMP LANDING, FLA. 34.8 3,000 --... 4. NORTH FORK BLACK CREEK 30 NEAR HIGHLAND, FLA. 48.9
2.000
' oo
50
.000 _, _-.__,_ l-4. I _a _0
ZO
__ __ i i ___ __t
I I _______ __..___C O5 0.2 1 2 5 10 20 30 40 50 60 70 80 90 95 9899 99.5 99.9 9199 PERCENT OF TIME DISCHARGE EQUALED OR EXCEEDED THAT SHOWN
Figure 17. Flow-duration curves for streams in the Black Creek basin.




REPORT OF INVESTIGATIONS No. 35 45
300 I FI I iT I
o200
too
80
60
60- Maximum period .2 50
.0 of deficient flow 40
S30
20 v-,Lowest average flow for indicated
a -period
S10 I I I I i lil
S 2 3 4 5 6 7 8 10 20 I 2 3 4 5 6 89 12 V )kV-I
Consecutive days Consecutive months
Figure 18. Discharge available without storage for South Fork Black Creek near Penney Farms, Florida (1939-60). 200 I I I I I I
100
80
u 60
40 Maximum period
CL of deficient flow
20
10
o 8
6
4- Lowest average
flow for indicated
period
2 I 1 I I l I I 1 l I l l 1 1
1 2 3 4 6 8 10 20, 1 2 3 4 6 9 12,
Consecutive days Consecutive months
Figure 19. Discharge available without storage for North Fork Black Creek near Middleburg, Florida (1932-60).




46 FLORIDA GEOLOGICAL SURVEY
lowest average discharge for a 10-day period was 4.6 cfs. These curves can be used advantageously for determining the adequacy of a stream for a use when a continuous flow is required.
The seasonal variation of streamflow in the Black Creek basin follows the variation of rainfall. High streamflow occurs sporadically in the summer months, June through August, as a result of heavy, local thundershowers. More general rainfall, lasting for longer periods, occur in September and October and is accompanied by high streamflow.
Although there has been some flood damage in the basin, there is no record of any extremely-destructive floods. However, flood damage in the past has been light because the land adjacent to streams was sparsely settled and not because of an absence of floods. Figure 20 shows four flood hydrographs for floods caused by heavy rains on May 20 and 21, 1959. The relative magnitude of floods will vary from area to area within the basin during a 3O I" I ' t'
\~a __-- 'A __ ______ ____ ___nem Pg,,.y Fams, Fla
,JGao --- ........
I
NW~h Folk 5Och Cw"k
r.* ic afflb Fla
s sI s so. sa- UK sAs Ga. 12ft sp1
20 21 22 23 24 25
MAY 1959
Figure 20. Hydrographs of floods during May 20-25, 1959, in the Black Creek basin.




REPORT OF INVESTIGATIONS NO. 35 47
heavy rainstorm. The flood in May 1959 inundated several county bridges and washed out road embankments along the South. Fork Black Creek where the flooding was most severe. From figure 21, which shows flood-frequency curves adapted from a report by R. W. Pride (1958), U. S. Geological Survey, a peak discharge of 2,000 cfs at the gaging station on South Fork Black Creek near Camp Blanding (drainage area, 34.8 square miles) is shown to be about a 3-year flood; that is, it will occur on the average once in 3 years. And, the peak discharge of 1,760 cfs on North Fork Black Creek near Highland (drainage area, 48.9 square miles) was less than a mean annual flood. A flood of this magnitude could be expected to occur at the Highland station at a frequency of less than 1 year.
Data have been collected on two of the four lakes in the basin (Whitmore Lake and Kingsley Lake). Whitmore Lake was sounded by a sonic depth recorder on May 11, 1960. From this sounding the depth-contour map, figure 22, was derived. The maximum depth found in this lake was 20 feet, with the exception of a small
O 15,000
z
0
o
z/' __ - ._ ,Lii --- -
10,000 0
8,000
" 6,000 O oL 5,000 -/- 0 / 00
S4,000 PO2,000 -0 4 10
0 -00
9
U,
1,000 1 -.
20 30 40 50 60 80 100 200
DRAINAGE AREA, IN SQUARE MILES Figure 21. Flood-frequency curves for the Black Creek basin.




48 FLORIDA GEOLOGICAL SURVEY R. 23 E.
'0 ~
120
101
I1
l / 2
1,, /
- ( .,,,/
XIS
10 ,/-I
- WHITMORE LAKE
( Cloy County)
S00 0 500 1000 1500 feet
Il I l T I I I I
15 Date of survey: May II, 1960 14
Contour interval: 10 feet
Data source: U.S. Geological Survey R. 23E.
Figure 22. Depth contours of Whitmore Lake.




REPORT OF INVESTIGATIONS NO. 35 49
-J
77
Z
S174
0
'W' 175
J174 r Fgr ECN 0 3
100 90 80 70 60 50 40 30 20 t0 PERCENT OF TIME
Figure 23. Stage-duration curve for Kingsley Lake (1947-60).
hole near the north shore which was made by dredging. Based on interpretations of the records from the sonic depth recorder and visual observations of the shoreline, the lake bottom is composed of sand overlain by a layer of silt and organic material.
Stage records have been collected on Kingsley Lake since
1945. The total range in stage since 1945 is 3.5 feet, which is exceptionally small for a Florida lake. The surface outlet readily conveys excess flood waters from the lake to North Fork Black Creek, which prevents extremely high lake stages. The surrounding shallow ground water readily replenishes the lake, which prevents extremely low lake stages. The combination of replenishment and removal of excess accounts for the favorable balance between gain and loss of water and for the exceptionally small range in stage. A stage-duration curve for Kingsley Lake is given in
figure 23.
Kingsley Lake, which is 85 feet deep, is possibly the deepest
lake in northern Florida (fig. 24). The lake is circular and the bottom slopes uniformly from the shoreline at about 1 foot per 50 feet to the depth of 20 feet, then slopes more gradually to a depth of about 30 feet, beyond which the slope increases to the maximum depth of 85 feet. The bottom is formed of fine sand, but rock
possibly is exposed in the deepest hole.
The Black Creek basin is well dissected by stream channels
which carry copious quantities of water. Topography and streamflow lend themselves well to the construction of small dams and reservoirs which would be ample for recreation and conservation which would help to equalize the uneven distribution of streamflow.




50 FLORIDA GEOLOGICAL SURVEY
e.... W3 ft 6beW m mN 16 15
- I'
17 /
I 1 1 / 1
11 I I
20 I
2122 23
KINGSLEY LAKE 1
ma.t Cf W CasN 15s
Cne mee 1se s0 28 27
..- .- .- -+ - ,- _- -- -+ -I It "urge: tUl 1issue al S or R.23E.
Figure 24. Depth contours of Kingsley Lake.
SANTA FE RIVER BASIN
The Santa Fe River basin covers an area of 1,440 square miles. Flow from the basin reaches the Gulf of Mexico by way of the Suwannee River. The Santa Fe River starts in Santa Fe Lake and flows generally westward, picking up flow from the tributaries, Sampson River, New River, and Olustee Creek, before the river disappears into a sinkhole at O'Ieno State Park, 5 miles north of High Springs. The river emerges abruptly from the ground after being underground for a distance of 3 miles. The entire northern boundaries of Alachua and Gilchrist counties are formed by the Santa Fe River. The basin is shown in figure 25.
The hydrology of the basin is very complex. The average runoff from the basin is about 22 inches per year. However, average runoff from subareas varies from 6 to 85 inches. Figure 26 shows the wide variation in runoff. On the average the basin receives 52 inches of rainfall per year. The ratio of runoff to rainfall varies by areas from about 1/10 to more than 11/2, which is an extreme variation within an area of 1,440 square miles. Topography and geology are among the causes of the unusual runoff conditions in this basin.
Major changes in streamflow characteristics occur in the vicinity of O'leno State Park. Above this point surface streams are




SANTA FE RIVER BASIN
--"( -, ' ; ',,, N.,,-.,.---,-. .. !\"4
IWI
-(, tS I
WI-0
LAIIE
0,j' r
/I ~t 2'> S \G ..... l-o P[Ill
01
Figure 25. Drainage map of the Santa Fe River basin showing data-collection sites.




, OJ
31 85
7 ) -... ..--I
.' 1
0 0 10 I MIL
Figure 26. Average runoff in inches per year from areas within the Santa
Fe River basin.




REPORT OF INVESTIGATIONS No. 35 53
prevalent throughout Union and Bradford counties and the northern part of Alachua County. The headwater tributaries along the northern boundaries of Union and Bradford counties (Olustee Creek, Swift Creek, and New River) are in a flat, swampy area. There are several lakes in these two counties that are connected to the system of streams by surface channels.
Below O'leno State Park there is a noticeable absence of surface streams. The stream channel has been cut into porous limestones. Sinkholes are prevalent and springs are numerous throughout this area. From the point where the river emerges from the ground downstream to the confluence with the Suwannee River, springs are visible along the channel, usually flowing from circular pools in the banks of the river. The large pickup in streamflow in this vicinity comes from springs. The lower half of the basin is covered with a relatively thin mantle of sands overlying porous limestone. Rain on this area seeps directly into the ground or is carried by short surface channels to sinkholes.
Flow characteristics above and below O'leno State Park are shown by the hydrographs in figure 27. The flow of Santa Fe River at Worthington is indicative of the hydrologic conditions above the park and the flow of Santa Fe River near Fort White is indicative of the hydrologic conditions in the lower basin. The Worthington station measures flow from the upper 630 square miles of the basin wherein surface streams receive a high rate of direct runoff, respond rapidly to rainfall, and recede rapidly to a low base flow. Streamflow at the Fort White station does not respond to rainfall as quickly, stays up for longer periods after rains, and has a much higher base flow. A comparison of extreme
tI6OO- _____ __i
200 I ..OO FI RIVE I I
2200 K 1__ ___OCT. NOV DEC JAN FEB MAR APR MAY JUNE JFLY AUG SEPT WATER YEAR 1958
Figure 27. Flow hydrographs for the Santa Fe River.




54 FLORIDA GEOLOGICAL SURVEY
flows of the two stations will also point up the difference in streamflow characteristics. At the Worthington station the average flow is 424 cfs, the maximum is 17,500 cfs, and the minimum is 0.5 cfs. At the Fort White station the average flow is 1,576 cfs, the maximum is 12,300 cfs, and the minimum is 609 cfs.
An average flow of 650 cfs enters the ground at O'leno State Park. This flow comes from four streams: 130 cfs, or 20 percent, from Olustee Creek; 240 cfs, or 37 percent, from New River; 100 cfs, or 15 percent, from Sampson River; and 180 cfs, or 28 percent, from the main stem and smaller tributaries.
Flow measurements made February 24, 1961, above and below the subterranean reach of channel showed a pickup in flow of 211 cfs in that 3-mile section; a flow of 574 cfs entered the ground and 785 cfs emerged from the ground. On the same day there was a pickup in flow of 160 cfs between the lower end of the subterranean reach and the High Springs gaging station on U. S. Highway 27, a channel distance of 5.5 miles; and between the High Springs and Fort White gaging stations, a channel distance of 7 miles, the pickup was 750 cfs.
Flow-duration curves for seven stations in the Santa Fe River basin are given in figure 28. Three of these stations, Santa Fe River near Fort White, near High Springs, and at Worthington, have records extending as far back as 1932; records for New River near Lake Butler extend back to 1951; the other stations: Santa Fe River near Graham, Olustee Creek near Providence, and Swift Creek near Lake Butler, have only 3 years of records, 195860. For the purpose of developing these flow-duration curves, records for all the short-term stations were extended to cover the period 1932-60. Although these flow-duration curves are not frequency curves, they can be used, with fair reliability, to predict the percent of time that a given discharge will be equaled or exceeded in the future.
Lakes within this basin are a major part of the water resources. There are eight lakes with surface areas of 0.4 square mile (250 acres) or larger. The largest is Santa Fe Lake with a surface area of 8.05 square miles. Other lakes in the basin are Lake Altho, Hampton Lake, Lake Sampson, Lake Rowell, Lake Crosby, Lake Butler, and Swift Creek Pond. All these lakes are tributary lakes. Records of stage have been collected on Santa Fe Lake, Lake Sampson, and Lake Butler. Stage hydrographs for these lakes are shown in figure 29. Lake Altho and Santa Fe Lake are connected and probably exhibit similar stage characteristics. Lake Rowell,




REPORT OF INVESTIGATIONS NO. 35 55
LRAINGE AREA
OWIR G STAT O SO-. MR
- ~SL SAA FE VER NEAR FOR sMRs. FLA. 1SO
- V 4 TER FLA 0
- SANTA FE RVER HEAR HA O. FLA NE5
- USEE RK RA FORSoREO E, FLA. SO
- 7. EOOFT W REE NEAR Z000LARE BUTLER. FA. 21t CRA A&P FLA. 13 MK BULE. LA 27
5.00 :I] N ikI I I
3POO
1,000
O J K
oo
S202
goo
DD
30
I
0.0 o 0 05 1 3 0 2 o 3 o 4 o 50 7 so a9 Rsw ". R it EROF O RGE EQUALED OR EXCEEDED TMT RafA
Figure 28. Flow-duration curves for streams in the Santa Fe River basin.




56 FLORIDA GEOLOGICAL SURVEY
144
42 -SAWTA FE LAXE
LAKE SAMPSON
-134'
132
30LAK BUTLER
I I I 1 t i I I I I I I i I l l l I I I I I I I I
1957 1958 1959 1960
Figure 29. Stage graphs of Santa Fe Lake, Lake Sampson, and Lake Butler.
Lake Crosby, and Lake Sampson are connected and exhibit similar stage characteristics. Lake Sampson loses water not only through its surface outlet but also through a drainage well on the western shore of the lake.
Surface-water supplies within the Santa Fe River basin are one of the area's major natural resources. -Bradford and Union counties are well dissected by stream channels that carry copious quantities of water. The high base flow in the lower reaches of the basin is unparalled in the State. This is evidenced by the fact that the area of 130 square miles west of High Springs has a runoff of 85 inches per year, or more than 11/ times the average rainfall.
ORANGE CREEK BASIN
The Orange Creek basin covers about 515 square miles situated in three counties: Alachua, Marion, and 'Putnam. Three large lakes (Orange Lake, Lochloosa Lake, and Newnans Lake) and their tributaries and connecting channels form the drainage system of the upper two-thirds of the basin which lies in Alachua County. A large part of the streamflow in the upper part of the basin is relegated to lake storage. The basin is shown in figure 30.
Hatchet Creek, a tributary to Newnans Lake, is the headwaters of the basin. Flow from Newnans Lake reaches Orange Lake by




REPORT OF INVESTIGATIONS No. 35 57
ORANGE CREEK BASIN
nnt P i C, th let cn G/en 8 GAI ESVILLE C, Sprin7g
ivaw x io cO
Surae ou tha f Cree k a riutry t O .N
waaRvr.Drn peid"o-oml-tgs Lcloa aei
CPb a
/
Figure 30. Drainage map of Orange Creek basin showing data-collection sites.
connects Prai ri e Creels, thee outlet channel from Newnans Lake, and River Styx, the inflow channel to Orange Lake. Orange Lake and Lochloosa Lake which are connected by Cross Creek both have surface outlets that form Orange Creek, a tributary to the Oklawaha River. During periods of normal stages, Lochloosa Lake is from 1/, to 3/4 foot higher than Orange Lake. The combined drainage area of the two lakes above their outlets is 323 square miles.
There have been extended periods of no flow from Orange and




58 FLORIDA GEOLOGICAL SURVEY
Lochloosa Lakes. Flow from Lochloosa Lake outlet ceased in May 1954. Flow from Orange Lake outlet ceased in May 1955 when the lake-surface elevation was about 55.0 feet. The levels of these lakes remained below the elevations of their outlets until 1957. There has been flow continuously throughout the period of record (194252; 1955-60) at the gaging station on Orange Creek at Orange Springs. The minimum flow there was 2.0 cfs for several days in May and June 1956. Discharge-duration curves for Orange Creek, Camps Canal, Orange Lake outlet, and Lochloosa Lake outlet are given in figure 31. The basin slopes from an elevation of 190 feet above sea level in the headwaters of Lochloosa Creek, a tributary to Lochloosa Lake, to an elevation of about 30 feet near the mouth of Orange Creek. Newnans Lake is about 9 feet higher than Orange Lake and Lochloosa Lake is from 1/2 to 3/4 foot higher than Orange Lake. The fall in water surface from Orange Lake to the gaging station on Orange Creek at Orange Springs is about 30 feet.
Average runoff from all areas within the basin is about 5 inches per year with exception of Little Orange Creek, a tributary entering below Orange Springs, from which the average runoff is about
8 inches per year.
Rainfall on the basin averages 52 inches per year. Five inches runs off as surface flow. The remainder is taken up by evaporation, transpiration, and seepage. Open lakes surfaces, from which there is maximum evaporation, cover about 10 percent of the basin. Flat, swampy areas, with luxuriant growths of vegetation, are numerous. Rain on these areas runs off very slowly, allowing evaporation and transpiration to take a heavy toll.
The elevation of the piezometric surface, that is, the pressure surface of artesian ground water, is higher than ground level in the northern three-fourths of the basin and lower than ground level in the southern part of the basin. The presence of flowing springs, such as Magnesia Springs north of Lochloosa Lake, Glen Springs at Gainesville, and of several flowing wells along the northeastern shore of Lochloosa Lake, attest to this fact. However, south of Orange Lake this condition is reversed. A sinkhole on the southwest shore of Orange Lake, at the town of Orange Lake, has been known to take water from the lake for extended periods.
Water leaving Orange Lake through the sinkhole, coupled with a statewide drought in 1954-57, caused the lake to be reduced from a normal surface area of 25.7 square miles to one of about 5 square miles. All lakes in the State were lowered to some extent by this extreme drought which was the most severe and widespread in the history of the State. However, Orange Lake was losing water




REPORT OF INVESTIGATIONS No. 35 59
,000
RANGE CREEK AT ORANGE SPRINGS, FLA.
Record used: Oct. 1942-Sept 1952 Oct. 1955-SeI. 1960
CAMPS CANAL NEAR ROCHELLE, FLA.
ecord used: Oct. 1957-Sept. 1960
13 to
LOLOSA LAKE OTLE ORANGE LAKE OUTLET NEAR LOCHLOOSA- FLA. AT ORANGE LAKE, FLA. Record used: Oct. 1946-p, 1955 Record used: Oct 1946-SApt 1955
1.0
0.1
001 05 0.2 a5 1 2 5 to 2 0 4 80 90 95 98 9 9 5 99.9 99.9 PERCENT OF TIME DISCHARGE EQUALED OR EXCEEDED THAT SHOWN Figure 31. Flow-duration curves for streams in the Orange Creek basin.




60 FLORIDA GEOLOGICAL SURVEY
into this sinkhole at a rate of 12 mgd on November 21, 1957, which accounted for some of the lowering of Orange Lake.
Data for Newnans Lake, Orange Lake, and Lochloosa Lake, are given in figures 32, 33, 34, and 35. The stage-duration curves in figure 32 show the total percent of time that a stage was equaled or exceeded during the period of record. The upper unshaded portion of the graphs in figures 33, 34, and 35 represents the highest 25 percent of recorded stages. The lower unshaded portion represents the lowest 25 percent of recorded- stages. The middle shaded portion represents the range of the middle 50 percent of recorded stages. These values are indicative of excessive, deficient, and normal lake stages.
ETONIA CREEK BASIN
Etonia Creek, a tributary to Rice Creek, has a drainage area of about 230 square miles. Rice Creek flows into the St. Johns River north of Palatka. The upper 150 square miles of the basin contain some 100 lakes. The largest of these is Lake Geneva which has an area of 2.73 square miles. These lakes are situated in the southwestern corner of Clay County and the northwestern corner of Putnam County. Many of these lakes have no surface outlets. Some are connected by surface channels to Etonia Creek. The basin is shown in figure 36.
Data have been collected on 11 lakes in this basin. The highest lake, Blue Pond, is at an elevation of 174 feet above sea level. Lake Grandin, at an elevation of 81 feet above sea level, is possibly the lowest. Eight of these lakes have been sounded: Blue Pond, Sand Hill Lake, Magnolia Lake, Crystal Lake, Brooklyn Lake, Keystone Lake, Lake Geneva, and Loch Lommond. All lakes sounded have maximum depths ranging from 25 feet for the shallowest to 47 feet for the deepest. Maps showing the depth contours of these lakes are given in figures 37 through 44.
Some lakes in this area have a wide range of stage. The severe drought of 1954-57 caused Brooklyn Lake at Keystone Heights to be lowered 20 feet. Pebble Lake, a small lake in Gold Head Branch State Park, had a 32-foot range of stage during the period from 1948 to 1956. However, some lakes in the area have less than a 5-foot range of stage. Stage graphs of nine lakes are given in figure 45. The basic cause of all stage fluctuations is variations in rainfall. However, on the average, all the basin receives the same amount of rainfall, 52 inches per year. The reasons that some lakes




REPORT OF INVESTIGATIONS No. 35 61
Ti
70
69
6B
66
NEWNANS LAKE Period of Record: Oct. 1946-Dec. 1952 Aug. 1957-Dec. 1960 65
64
6!
II
03
62
S61
tOO 90 60 70 60 50 40 30 20 Io 0 PERCENTT OF TIME Figure 32. Stage-duration curves for Newnans Lake, Orange Lake, and Lohloosa Lke.
Period of Record: July 1942-Dec. 1952 ra \ Oct. 1956--Dec. 1960
L60
50
50
ORANGE LAKE Period of Record: Jart 1943-Dec. 1960
SG
54
53
500 9D 0 70 6 0 40 30 20 10 0 'PERCENT OF TIME
Figure 32. Stage-durat ion curves for Newnans Lake, Orange Lake, and Lochloosa Lake.




62 FLORIDA GEOLOGICAL SURVEY
73V
664
71..
.. .. EXCESSIV
67 - F- -
66 ___---,_-_I. DEFICIENT
-lower 25 percent
JAN. FEB. MAR. APR MAY JUN JUL. AUG. SEP. OCT. NOV DEC.
Figure 33. State graphs for Newnans Lake.
60 613
EXCESSIVE I
I'I I I i I o. ~ K : I':,,
NORMAL
Smimdddle 50 percent :'
4 7
6 DEFICIENT
- 10 lwr 25 percent
m 52
50
JAN FEB. MAR. APR. MAY JUN. JUL. AUG. SEP. OCT. NOV. DEC,
Figure 34. Stage graphs for Orange Lake.




REPORT OF INVESTIGATIONs No. 35 63
63
EXCESSIVE
upper 25 percent
olwer 25 percent
5 3
JAN FEB. MAR. APR MAY JUN JUL AUG. SEP OCT NOV DEC.
Figure 35. Stage graphs for Lochloosa Lake.
vary more than others are differences in topography and geologic formations. Topography dictates which lakes are connected by surface channels. Lakes in this basin are situated among high sandhills that are from 130 to 210 feet above sea level. These hills are as much as 70 feet above the adjacent lake surfaces. The character, composition, thickness, structure, and extent of the underlying geologic formations, and their hydrologic properties, are controlling factors in the movement of water into and out of the lake. Sands and clayey sands underlie the basin to a depth of as much as 90 feet below the surface. Most lakes are believed to be floored in these materials. The sands overlie thick, relatively impervious clays and limestones.
Data have been collected on the six highest lakes that form the headwaters of Etonia Creek: Blue Pond, Sand Hill Lake, Magnolia Lake, Brooklyn Lake, Keystone Lake, and Lake Geneva. These lakes are in Clay County near the town of Keystone Heights. A profile of these lakes is given in figure 46.
During the statewide drought of 1954-57 all lakes in this area receded to all-time low stages. Low stages affected the utility of Brooklyn Lake possibly more than any other lake in this immediate area. However, in 1958 the drought was broken by above-normal rains and by 1959 Brooklyn Lake was filled to overflow capacity.




64 FLORIDA GEOLOGICAL SURVEY
ETONIA CREEK BASIN s
& Leete efst-olcio ie;nme
=0I Pic
I 1, ,,.)
Lvl of .... ,,t.; 5,., N
refrs e site member, table 3
Figure 36. Drainage map of the Etonia Creek basin showing data-collection sites.
A water budget for Brooklyn Lake for the period August 1957 to October 1960 was computed by Clark, Musgrove, Menke, and Cagle (1963). This water budget showed that 22,000 acre-feet of water entered Brooklyn Lake during that period as surface flow through the channel from Magnolia Lake and that 8,000 acre-feet of rain fell directly on the lake surface. Factors accounting for the losses of water from the lake are seepage, 11,000 acre-feet; evaporation, 7,000 acre-feet; and surface flow, 2,000 acre-feet. During this period, the amount of water stored in the lake increased 10,000 acre-feet. A schematic diagram of this water budget is given in figure 47. The report by Clark, Musgrove, Menke, and Cagle (1963) furnishes more detailed information on Brooklyn Lake and surrounding lakes.
Many lakes in this area are landlocked and depend entirely on rainfall directly on the surface of the lake and seepage from ground to maintain their supply of water. Lake elevations are generally lower to the south and southeast as the land elevations of the basin become lower. However, the relative elevations of the lakes vary




REPORT OF INVESTIGATIONS No. 35 65
R. 23 E.
I 17
+ -Elevation: 1738 ft. above mean too level
19
II 20
BLUE POND "
(Claoy County) so0 0 s0 to00 Is0 feet
Date of survey: Nov. 29, 1960
Contour Interval: 10 feet
I Data source: U.S. Geological Survey R.23E.
Figure 37. Depth contours of Blue Pond.
locally. On January 27, 1961, the elevation of Hutchinson Lake, a small landlocked lake immediately south of Lake Geneva, was 106.4 feet above sea level-0.8 foot higher than Lake Geneva.
Runoff from this basin is extremely low. Based on 21 months of streamflow records collected at Florahome, the estimated average runoff from a drainage area of 172 square miles is 4 inches per year. Runoff is possibly higher in the lower part of the basin. Seepage to the deep ground water, evaporation from lake surfaces, and transpiration take most of the rain that falls on the upper part of the basin.
QUALITY OF SURFACE WATERS
INTRODUCTION
A discussion of streamflow and lake levels in Alachua, Bradford, Clay, and Union counties has been presented. In this section the chemical quality of water in streams and lakes in those counties is




ft 23 E.
levelloen: 138.1 Ift above mean s level
\. 00 ----,-w29 -1 27 to 28
so
+
a t ~o
32 33 34
SAND HILL LAKEI
(clay county)
1000 0 1000 2000 3000 feet
Date of survey: Nov. 28, 1960 Contour Interval: 10 feet t-.-..
Data source: U. S. Geological Surveydam
0
R. 23 E.
Figure 38. Depth contours of Sand Hill Lake.




R.23E.
Elevation: 14.7 ft. above mean sea le Isvel
o I
0 0l
5 1 450 Np 4s 00oo
9i
,I I
Date of survey: Nov. 28, 1980 MAGNOLIA LAKE P
-(C:loy County) q ./-
-I9 Dote of survey: Nov. 28, .1980 Contour interval: O10 feet Data source: u.S. Geological Survey R. 23E.
Figure 89. Depth contours of Magnolia Lake.




68 ,FLORIDA GEOLOGICAL SURVEY
R22E R23E
0/
636 31
g 25 1O
f ii1
-)
I I
150,
12 1
CRYSTAL LAKE
(Clay and Bradford Counties)
500 0 500 1000 1500 feet
Date of survey: May 10, 1960
'I'/
Contour interval: 10 feet
Data source: u S. Geological Survey R.22E R.23 E.
Figure 40. Depth contours of Crystal Lake.
I ,
',] -/ I 'Jo /
CRYSTAL LAKE
C lay and Bradford Counties)
500 0 500 IOO0 1500 feet
0 ate of survey: May I0, 1960
*Contour interval: 10 feet
1 Data source: U. S. Geological Survey R22E.. R 23E.
Figure 40. Depth contours of Crystal Lake.




R 2C R 23E
IElevation: 116.9 ft above mean sea level
12 7 9
I---+ I- _13 1
-BROOKLYN LAKE
(Cly and Bradford Counties) --- "".. . .' "" 00 0 00 000 feet 1 1 Date of survey: April 25, 1960 e- -. 2I2 Contour interval: 10 feet"
100
00
I ~Data source: U. S. Geological .Survey
%ac
I I I I... Date of survey: April 25, 1960 19 202
CotuIneva 0fe Data source: U. S. Gol ogical S urvey
R 22E. R 23E.
Figure 41. Depth contours of Brooklyn Lake.




70 FLORIDA GEOLOGICAL SURVEY R.23E.
Elevation: 108.6 feet above mean sea level
I f
( 1
1 19 KEYSTONE LAKE (Clay County)
200 0 200 400 600 feet
1 1 1 1 1I\
Date of survey: April 26, 1960
Contour interval: 10 feet
Data source: U. S. Geological Survey R.23E.
Figure 42. Depth contours of Keystone Lake.




R, 22E. R 23E.
1 I
sElevation: 102.7 ft. above mean sea level 24 19 \$ 20. 21
4
(+
30
-' *Y )i (I 0
25 28
120-,
.I 1_ 29
36, \
, I ,\ 2._,- ,, /
4' tC 1 ....,. /2- /
36 )V
LAKE GENEVA 31 33 Clay and Bradford Counties) ooo1000 0 ooo1000 2000 oo3000 feeti
........ 1 I I
Date of survey: April 26,27, 1960 32
Contour Interval: 10 feet
R 2 RData source: U. S. Geological Survey RF 22E, R,23E.c
Figure 43. Depth contours of Lake Geneva.




72 FLORIDA GEOLOGICAL SURVEY
R. 23 E.
I
8 9
+ ,o* I.o -.
Elevation: 95.4 feet above mean sea level --. .
17 de Ol
0
/ s I
I
I /
I.
- tO
to / tO /
* 0 00
%
16
LOCH LOMMOND (Clay County)
o00 0 tOo 200 300 400
Date of survey: May 10, 1960
Contour interval k 10 feet
Data source: U.S. Geological Survey R. 23 E.
Figure 44. Depth contours of Loch Lommond.




REPORT OF INVESTIGATIONS No. 35 73
Blue Pond 170
135
Sand Hill Lake- 130
I2 GMagnolia Lakea 120 a115
SBrooklyn Lake
10
1 Pebble Lake
90
80 00
I r fI I Il l I l I I I i l i I I l i ti l l I .i i i t a i i l l 1 i I i t
1957 195 1959 1960
Figure 45. Stage graphs of nine lakes near Keystone Heights, Florida.




74 FLORIDA GEOLOGICAL SURVEY PLAN <
PROFILE
Figure 46. Profile of lakes near Keystone Heights, Florida.
twLo,
22,000 A5140
WATER BUDGET
Figure 47. Water budget of Brooklyn Lake for the period October 1957 to September 1960.




REPORT OF INVESTIGATIONS No. 35 75
described. Just as the quantity of surface waters is variable, so is the quality. Both nature and man contribute to the changes in the concentration of matter dissolved in the waters of the area. Through natural actions, minerals in the crust of the earth affect the chemical content of the waters with which they come in contact. Man's use of water and land affects both the chemical and the sanitary quality. This report is concerned only with the chemical and physical quality and contains no information on sanitary aspects and suitability for use when such use is related to bacteriological quality.
EXPLANATION OF TERMS
Concentration is a ratio or proportion. It can be expressed in many different ways-parts per million, equivalents per million, grains per gallon, etc. The use of parts per million for expressing the results of water analyses has been so frequent that it has become conventional; however, this does not imply superiority of this ratio over other ratios for expressing quality of water. Conversion from one unit to any other unit is possible with the proper conversion factor. Because parts per million is used in this report as a means of expressing analytical results, an example of its magnitude is given. Water having a concentration of 1 ppm means that 1 million pounds of such water contains 1 pound of material dissolved in 999,999 pounds of water.
The color of water is compared to that of colored discs which have been calibrated to correspond to the platinum-cobalt scale of Hazen. The unit of color is that produced by 1 milligram of platinum per liter.
Residue on evaporation at 1800C is the concentration of substances dissolved in water that remain in a solid state at 180'C. The residue on evaporation at 180oC includes organic matter and mineral matter whenever both are present. Hardness of water is the property of water attributable to the presence of calcium and magnesium and is expressed as equivalent calcium carbonate. Mineral matter is the concentration of dissolved inorganic earth materials. The term organic matter refers to an estimate of the concentration of dissolved organic matter. The concentration is calculated by subtracting the mineral matter from the residue on evaporation at 1800C. The organic matter which is leached from vegetation characteristically colors natural waters. Whenever organic matter is absent, residue on evaporation at 180'C and mineral matter become synonymous.




76 FLORIDA GEOLOGICAL SURVEY
WATER TEMPERATURE
The temperature of surface water generally varies with air temperature, but it is sometimes influenced by ground-water inflow and industrial activities, especially during low-flow periods. When streams and lakes receive large quantities of ground-water inflow during low-flow periods, the water temperatures tend to be higher than air temperatures during winter months and lower than air temperatures during summer months. Surface water temperatures usually are increased after the water has been used for such purposes as cooling and air conditioning. Large streams and lakes usually have small diurnal variations in water temperatures, whereas small streams may have a daily range of several degrees and may follow closely the changes in air temperatures. Large quantities of water on the earth's surface tend to moderate the air temperature.
The observed water temperatures of streams and lakes investigated in Alachua, Bradford, Clay, and Union counties generally were above 450F in the winter months and less than 850F in the summer months. The observed daily water temperatures of the Santa Fe River near High Springs, which receives large quantities of ground-water inflow, ranged from 600 to 800F from October 1959 to September 1960. This water would be desirable for cooling and air conditioning. The daily water temperature of the Santa Fe River at Worthington, which is mostly all surface runoff, ranked from 410 to 84oF. from July 1957 to September 1960. Table 4 shows the maximums, minimums, and average observed
TABLE 4. Maximum, Minimum, and Average of Observed Daily Water
Temperatures of Streams in Alachua, Bradford, Clay and Union Counties, Florida
Fahrenheit
Stream Max. Min. Average
1. New River near Lake Butler,
Aug. 1957-Sept. 1958 850 390 700
2. North Fork Black Creek near Highland,
Oct. 1958-Sept. 1959 800 400 640
3. Santa Fe River near High Springs.
Oct. 1959-Sept. 1960 800 600 720
4. Santa Fe River at Worthington,
Sept. 1957-Sept. 19601 840 400 660
5. North Fork Black Creek near
Penney Farms, Oct. 1958-Sept. 1959 810 500 690
IContinuous record.




REPORT OF INVESTIGATIONS NO. 35 77
daily water temperatures of several streams in Alachua, Bradford, Clay, and Union counties.
FACTORS AFFECTING. CHEMICAL QUALITY
Rain as it falls to earth contains little or no dissolved matter. The mineral matter is usually limited to dissolved gases, notably nitrogen, oxygen, and carbon dioxide. In coastal areas, sodium chloride may be deposited by rainfall and windblown spray. The solvent action of water is greatly increased by the presence of carbon dioxide, absorbed from the atmosphere and from the soil, which enables it to break down nearly all minerals and form new compounds. The amount and type of mineral matter taken into solution by water depends, among other things, upon the availability of carbon dioxide for the weathering process, the nature of the minerals present, and the length of time the water is in contact with the minerals.
As a stream flows from the higher to the lower regions of its drainage basin, it receives the inflow of many tributaries and a large amount of ground-water seepage. Solution of materials from the streambed is aided by scouring of the bed, reaeration at the surface, and the photosynthetic activity of aquatic growth. Differences in the geology of various regions, variations in topographic features, and climatic conditions will affect the chemical character of a surface stream at various points along its reach. Human activities such as diversions, impoundments, and the disposal of agricultural, industrial, and domestic wastes greatly affect water quality in some areas.
Industrial and population expansion will play a dominant part in an ever-increasing demand on the water resources of the area. Increased use of water can logically be expected to affect the chemical quality of surface water as it is used and reused by industry, agriculture, and domestic service. Therefore the quality of water in streams can vary greatly due to many manmade and natural factors.
The chemical-quality data are considered to be representative of the water quality of the streams during the period of study.
To describe the general water quality and the water-quality variability of streams, the average, maximum, and minimum values of chemical constituents and physical qualities were determined for the period of July 1957 to September 1960. Table 5 is a tabulation of the average, maximum, and minimum values for the period of study.




TAliI, 5. Average, Maximum, Minimum Values Observed for Sublstances Dissolved in Streams and ILakes
Chemical analyses In parts per million, July 19657 to September 1960 except as otherwise stated Hardness 0
Sas CaCOl
SANTA FE LAKE NEAR MELROSE,-Semi-annual
Average 78 1.6 0.08 2.8 1.,2 7.8 0.4 4 4.2 12 0.1I 2 4 8 1 2 57 2 Maximum 88 6.0 .00 8.0 1.7 7.8 .I 0 88 4 8 2 1 0 8 6 45 I
0 15 88 54 ] ] 8 0 0
Minimum 60 .0 .06 1.4 ,.60.8 .1 2 1.0 12 .0 0 28 883 59 5.3 10 LITTLE SANTA FE LAKE NEAR MELROSE-Semi-annual
Average 70 2.6 0. 82.8 1.2 7.8 0.4 10 2 12 0,1 0.813 8 4 12 14 B 62 5.0 26 Maximum 88 6.05 0 8.0 1.7 7.8 .4 25 7.6 12 .2 1.0 88 52 33 2 10 92 6.0 45
Minimum 54 .4 2.0 1.0 6.0 .1 4 .0 11 .0 .0 25 42 15 9 5 56 5.4 50
HAMPTON LAKE AT HAMPTON BEACH-Semi-annual
Average 68 1.8 .15 2.8 1.3 5.6 .3 2 7.4 9.6 .1 .2 30 50 22 11 9 60 5.1 27
Maximum 88 2.7 .26 8.6 1.6 6.4 .6 4 12 11 .2 .4 87 58 26 13 12 72 5.5 45 Minimum 57 1.0 .05 1.4 1.0 4.3 '.0 1 1.6 8.0 .0 .0 19 37 18 9 6 46 4.9 10
SANTA FE RIVER AT GRAHAM-0-8 week intervals
IIl
Average 8 8.3 1.9 6.2 .4 9 2.5 9.8 .2 .4 82 93 61 16 9 60 5.4 275 Maximum 8. .7 12 4.6 7.5 .8 44 8.8 16 .5 .7 7 188, 99 49 14 120 6.4 500 Minimum .8 .1 1.2 .5 2.0 .0 0 .4 8.5 .1 .1 13 44 22 7 0 80 4.4 180
Minimum 54 8 1. 2.0 .0 4 31 .0 .0 21.1 44 2 0 4 5 .4 s80




SAMPSON LAKE AT SAMPSON C.TY NEAR STARKE-Semi-annual
Average 76 2.8 0.19 7.8 1.8 9.8 1.0 11 15 8.5 0.2 0.2 0.0 61 90 31 26 16 112 6.2 93
Maximum 90 6.2 .21 9.6 3.6 15 1.6 20 24 11 .3 .5 .0 97 122 60 89 29 174 6. 20 Minimum 58 .7 .16 6.0 .5 2.2 .7 6 2.0 6.0 .1 .0 .0 37 68 16 19 8 74 5.9 15
SAMPSON RIVER AT GRAHAM-Semi-annual
Average 64 3.1 .24 7.6 2.6 10 .7 18 22 .6 .1 64 88 24 115 6.4 78 6 31 a 2 a 3ol 124 so 48 22 176 7.3 150
Maximum 80 8.8 .29 12 4:4 16 1.2 1 8 1 3 .1 10 1 J 12 4 3 4 23 50 Minimum 49 2.5 .20 4.2 .9 5.4 .1 2 4.8 6.0 1 .0 28 67 9 14 5 63 5.0 5
HATCHET CREEK NEAR CONFLUENCE OF SANTA FE RIVER NEAR GRAHAM--Semi-annual
Average 66 44. 8 .9 1.5 3.6 .3 13 1.8 7. 1 .2 .1 30 59 8 16 5 57 5. 154
Maximum 78 9.2 .42 13 4.5 4.7 .9 55 8.5 9.5 3 70 76 56 51 8 115 6.9 280 Minimum 54 1.8 .25 .4 .4 2.0 .0 0 .4 2.5 .1 .0 8 42 21 2 2 29 4.5 80
ROCKY CREEK NEAR LaCROSS-Semi-annual
Average 65 7.1 .82 7.4 2.8 5.6 1.5 22 0.0 12 .4 .0 54 86 32 30 12 90 6.3 101 aximu 74 9.6 1.6 10 5.0 8.7 2.4 43 9.0 18 .4 .1 80 111 52 44 18 126 7.3 130 Minimum 55 8.4 .31 2.8 .9 2.9 .1 4 2.8 5.5 .2 .0 22 49 11 10 5 41 5.5 45
ALLIGATOR CREEK NEAR LAWTEY OFF STATE ROADS 16 AND 225-Semi-annual
Average 70 4.0 0.17 18 2.0 5.0 0.9 48 .0 5.5 .4 .3 8 70 11 40 2 106 6.4 0 Maximum 86 5.0 .28 25 .5 7.0 1.8 95 4.0 6.5 .7 .4 101 103 2 77 0 11 7.6 10 Minimum 55 2.9 .06 1.2 .4 3.1 .0 2 2.0 4.5 .2 .2 16 36 20 4 3 30 5.8 90
WATER OAK CREEK AT STATE ROAD 25 NEAR STARKE-Semi-annual
Average 68 9.4 .22 5.8 2.8 5.3 .7 25 2.0 8.8 .1 .1 4 68 21 25 4 75 6.2 97
Maximum 82 18 .23 10 7.2 0.2 1.2 62 2.8 14 .2 2 94 110 25 54 6 143 7.0 110 Minimum 56 2.8 .21 2.0 .2 2.8 .1 4 .8 3.8 .1 .0 15 86 16 6 2 31 5.6 90




TABLE 5, (CONTINUED).
Hardnean
au CaCOI
0 s 0
LAKE BUTLER AT LAKE BUTLER-Semi-annual
Average 76 2.0 .18 2.6 1.2 5.4 0.5 5 4.0 9.6 0.2 0.0 0.1 28 59 82 12 7 57 5.7 55
Maximum 94 4.8 .24 8.2 1.9 7.8 .8 7 7.2 12 .2 .2 .8 89 72 87 10 11 72 6.1 70
Minimum 00 .7 .09 2.2 .5 8.5 .1 2 .8 6.0 .0 .0 .0 19 41 22 8 2 40 5.2 40
BUTLER CREEK NEAR LAKE BUTLER-Semi-annual
Average 61 2.9 .25 4.6 1.6 8.9 .2 12 2.9 8.1 .2 .4 .1 81 04 62 18 8 so 5.2 812
Maximum 76 8.8 .80 11 4.8 6.1 .7 40 8.0 10 .8 1.0 .2 65 146 81 45 12 104 6.6 500 Minimum 55 1.9 .17 1.6 .5 2.0 .0 0 .4 4.8 .1 .1 .0 16 65 47 7 6 88 4.7 180
NEW RIVER NEAR LAKE BUTLER
Average 70 7.2 8.8 8.38 6.4 0.7 88 4.2 9.9 .8 1.5 60 104 42 86 8 99 6.8 187 Maximum 85 1 80 10 15 2.8 114 11 20 .5 7.7 159 189 78 106 10 278 7.6 460 Minlinum 89 2.6 8.6 .2 2.0 .0 6 .4 8.8 .2 .0 21 64 13 18 8 88 5.8 90
SANTA FE RIVER AT WORTHINGTON-daily
Average 66 7.8 6.4 2.6 6.5 .4 21 7.0 9.8 .2 51 98 42 26 10 84 6.5 187 Maximum 84 21 18 7.5 18 1.8 64 22 62 .5 1.7 107 187 98 76 20 204 7.4 860 Minimum 40 1.9 8.2 .9 8.8 .0 0 .4 1.0 .0 .0 22 57 7 12 0 88 8.6 60
]Daily from July 1957 to September 1958, C-8 week intervals October 1958 to September 1960.




SWIFT CREEK NEAR PROVIDENCF--Semi-annual
average 64 5.6 0.86 8.2 2.0 4.2 0.2 7 2.2 8.5 0.2 0.1 0.4 80 79 49 16 10 51 5.6 198
Maximum 78 8.7 .87 4.0 8.4 6.0 .4 10 8.5 18 .8 1 .9 40 10 70 24 16 70 6.0 250 Minimum 55 8.0 .88 1.4 .9 2.5 .0 2 .8 8.8 .2 .0 .0 16 58 87 7 6 80 4.9 160
OLUSTEE CREEK NEAR PROVIDENCE-6-8 Week intervals
Average 68 5.1 .51 8.2 1.5 8.6 .8 8 1.7 7.7 .8 .5 29 84 55 14 8 48 5.5 254
Maximum 80 11 1.5 5.6 8.8 5.7 .7 20 4.0 11 .4 1.8 44 108 80 26 14 71 6.6 440 Minimum 50 1.2 .28 1.8 .2 2.0 .0 2 .0 8.5 .2 .0 16 49 81 7 2 29 4.9 120
SANTA FE RIVER AT HIGH SPRINGS2
Average 69 11 0.80 89 5.7 7.8 0.6 100 86 12 .8 .4 157 198 86 128 42 268 7.2 117 Maximum 80 20 .56 66 0 10 1.0 168 69 16 .4 1.8 260 299 62 206 70 482 8.8 280 Minimum 60 8.9 .11 6.0 1.0 8.8 .0 16 4.8 8.0 .0 .0 82 62 0 19 6 57 6.4 5,
NEWNANS LAKE NEAR GAINESVILLE-Semi-annual
Average 71 1.7 .88 4.0 1.8 5.4 .6 11 2.3 7.9 .2 1.0 0 29 64 87 15i 7 61 5.9 80
Maximum 88 8.0 .65 5.6 1.7 9.0 1.0 21 8.2 14 .8 4.4 .1 45 76 41 21 9 86 0.8 110
Minimum 55 .1 .14 8.2 .9 8.8 .0 4 1.2 2.5 .2 .0 .0 21 53 81 12 4 49 5.8 50
CAMPS CANAL NEAR ROCHELLE-Semi-annual
Average 69 1.9 .88 8.8 1.0 4.6 .2 8 2.5 8.2 .2 1.6 .2 28 52 19 18 7 55 5.7 85
Maximum 84 2.6 .66 4.4 1.1 5.2 .5 10 4.8 10 .2 4.5 .5 82 64 88 15 9 68 5.9 110
Minimum 55 1.1 .08 8.2 .7 8.9 .0 4 .8 5.8 .1 .0 .0 24 29 5 12 4 48 5.5 60
LOCHLOOSA CREEK AT GROVE PARK-Semi-annual
Average 67 6.4 .28 8.6 1.0 5.1 .4 9 1.5 8.5 .2 .2 .4 82 74 42 17 9 58 5.7 177
Maximum 88 11 .40 4.4 2.7 7.1 .9 14 2.4 12 .8 .7 47 02 45 22 12 78 6.1 220 Minimum 58 2.2 .07 2.0 1.0 8.8 .0 4 .4 5.0 .2 .1 .0 17 60 '89 9 6 40 6.4 150
Daily October 1959 to September 1960, 6-8 week intervals July 1957 to September 1959.




TABLE 5, (CONTINUED),.
Hardness
Sas CaCO3,
LAKE LOCHLOOSA NEAR LOCHLOOSA-Semi-annual
Average 70 17 12 2. 0.5 37 7.0 12 0.2 0.6 0. 6 77 21 40 l9 112 6.7 45
2.8 TO 1 16V t4o
Maximum 85 5.7 .56 15 .8 7.8 1.0 50 12 16 1.0 1.1 84 91 0 51 12 142 6.8 75 Minimum 59 .0 .06 8.0 1.7 5.8 .1 20 3.2 10 .2 .0 .0 44 49 5 29 5 88 6.6 15
ORANGE LAKE AT HEAGEY'S FISHING CAMP-Semi-annualI
Average 60 1.4 .18 6.9 1.8 5.4 .0 20 2.0 8.8 .2 .4 37 57 20 28 6 71 6.4 52
Maximum 88 2.0 .16 7.6 1.7 6.8 .0 20 2.4 10 .3 .8 89 67 28 24 7 79 0.5 65 Minimum 58 .7 .10 6.0 1.1 4.8 .1 20 1.2 7.5 .2 .2 84 46 8 22 6 65 6.4 45
ORANGE LAKE NEAR BOARDMAN-Semi-annual
Average 78 8.8 .20 a.3 1.6 4.6 .4 20 1.0 8.4 .2 .8 87 58 28 22 6 71 6.4 62
Maximum 88 4.8 .28 6.8 1.9 4.7 .8 21 8.0 10 .8 1.3 42 66 80 25 8 88 6.5 80 Minimum 59 2.8 .16 6.0 1.2 4.6 .1 18 .8 7.0 .1 .2 88 49 16 20 4 61 6.8 50
CRYSTAL LAKE NEAR KEYSTONE HEIGHTS-Semi.annual
Average 72 1.7 .04 2. .5 8.1 .5 8 2.4 4.5 .0 .1 .0 19 21 8 8 2 88 6.6 6
Maximum 488 4.4 .05 4.0 .7 8.8 1.0 18 8.5 5.5 .1 .2 .0 26 81 7 11 8 41 7.7 15
Minimum 61 .0 .02 1.4 .2 2.7 .0 8 1.6 3.5 .0 .0 .0 15 16 1 5 0 27 5.7 2




SAND HILL LAKE NEAR KEYSTONE HEIGHTS-Semi-annual
Average 74 2.5 0.9 0.9 0.5 8.2 0.1 8 2.0 5.0 0.1 0.1 0.0 17 22 6 4 2 28 5.4 10
Maximum 87 4.0 .23 1.4 .7 8.6 .4 4 8.5 5.8 .1 .2 .0 20 26 11 6 4 87 5.7 88
Minimum 55 1.3 .01 .4 .4 2.8 .0 1 .8 4.2 .0 .0 .0 14 16 2 4 0 24 4.8 2
MAGNOLIA LAKE NEAR KEYSTONE HEIGHTS-Semi-annual
Average 67 1.8 .05 1.0 .8 2.8 .1 8 2.4 4.6 .0 .1 .0 14 20 6 4 1 26 5.6 11
Maximum 88 1.9 .07 1.2 .6 2.9 .2 4 2.8 5.0 .1 .5 .0 15 28 14 4 2 28 6.1 20
Minimum 56 .8 .02 .8 .1 2.6 .0 2 1.8 4.0 .0 .0 .0 13 15 2 4 0 24 5.1 8
LAKE BROOKLYN NEAR KEYSTONE HEIGHTS-Semi-annual
Average 75 .0 .08 1.8 .7 3.6 .2 8 4.1 5.8 .0 .1 .0 18 28 5 6 4 85 5.5 4
Maximum 88 1.4 .05 1.6 1.2 4.4 .4 4 5.5 7.0 .1 .2 .1 21 84 18 9 8 41 5.7 10
Minimum 60 .2 .02 1.0 .2 2.6 .0 1 2.5 4.8 .0 .0 .0 14 19 1 4 2 26 5.1 2
LAKE GENEVA NEAR KEYSTONE HEIGHTS-Semi-annual
Average 70 .9 .01 1.5 1.1 6.1 .6 2 5.8 9.8 .1 .1 26 81 5 8 6 54 5.4 4
Maximum 88 2.6 .02 2.0 1.8 6.4r 1.0 4 6.8 10 .1 .2 28 84 8 8 7 s 5.6 10 Minimum 60 .0 .00 .8 .7 5.6 .0 1 8.0 8.5 .0 .0 26 26 2 8 4 52 5.1 0
JOHNSON LAKE AT GOLD HEAD BRANCH STATE PARK NEAR KEYSTONE HEIGHTS-Semi-annual
Average 71 8.1 0.05 0.7 0.8 2.8 .1 8 2.5 3.7 .0 .1 .1 14 17 4 3 1 22 5.5 15
Maximum 84 8.8 .05 1.2 .5 2.4 .4 4 8.2- 4.0 .1 .1 2 20 20 6 4 8 24 5.9, 80
Minimum 59 2.4 .04 .4 .2 2.0 .0 2 .0 8.2 .0 .0 .0 11, 14 1 2 0 20 5.2 5
PEBBLE LAKE NEAR KEYSTONE HEIGHTS-Semi-annual
Average 72 2.1 .08 .8 .8 2.5 .2 3 1.6 8.7 .1 .1 .2 18 14 2 4 1 22 5.5 4
Maximum 85 4.7 .05 1.0 .5 8.4 .5 4 2.8 4.0 .1 .4 .4 18 21 8 4 2 24 5. 10
Minimum 61 1.0 .01 .8 .1 2.0 .0 2 .8 3.5 .0 .0 .0 10 10 0 8 0 19 5.2 0




TABLit 5, (CONTINUED).
Hardness
0 as 0800, 0
00
HALL LAKE NEAR KEYSTONE HEIGHTS-Semi-annual
Average 71 0.0 .02 2.0 1,8 7.4 6.4 1 18 18 0.1 0.1 0.0 80 45 12 18 12 80 4.0 4 Maximum 81 1.1 .04 2.4 2,1 8.4 .0 2 10 14 .1 .2 .1 47 02 25 14 .18 89 5.8 10 Minimum 59 .0 .01 1.0 1.6 0.1 .0 0 11 12 .1 .0 .0 85 87 8 11 10 74 4.7 0
SMITH LAKE NEAR KEYSTONE IIEIGHTS-Semi-annual
Average 72 .8 .08 2.0 2.1 11 2 15 18 .1 .1 .0 52 04 12 16 15 108 5.2 5 Maximum 88 1.4 .04 8.6. 2.4 14 1.4 8 20 22 .2 .4 .1 68 74 14 19 18 128 5.0 10 Minimum 59 .0 .01 2.0 1.9 9.1 .0 1 8.8 14 .0 .0 .0 47 01 11 14 12 94 4.9, 0
LAKE GRANDIN NEAR INTERLACHEN-Semi-annual
Average 78 0.7 .08 2.0 1.2 5.9 0.1 5 5.5 0.7 .0 .1 .0 28 85 7 10 5 54 5,6 7
Maximum 80 1.5 .12 2.2 1.8 6.2 .8 6 04 10 .1 .2 .1 28 89 12 10 6 57 5.7 10 Minimum 60 .0 .05 1.8 1.0 5.5 .0 4 4.0 9.5 .0 .1 .0 27 82 4 10 8 51 5.5 5
KINGSLEY LAKE NEAR CAMP BLANDING-Semi-annual
'Average 78 1.1 .02 2.7 .9 5.8 .4 7 4.9 8.7 .1 .0 28 80 8 11 4 51 .8 6
Maximum 2 1.9 .08 8.4 1.0 0.2 .6 8 5.6 10 .1 .1 82 7 7 12 5 57 0.8 8 Minimum 56 .8 .01 2.2 .7 4.7 .2 4 2.0 8.0 .0 .0 20 22 2 10 8 8 5.9 5
.0 .inmu 20 2 16 e .




NORTH FORK BLACK CREEK NEAR HIGHLAND
Ae68 6.8, 0.85 12 1.9 16 0.5 5 54 7.6 0.2 0.4 102 180 28 88 88 178 5.8 94 Maximum 80 88 .54 82 6.1 72 1.9 '6 85 2 .4 8.6 816 886 62 102 492 6. 280 Minimum 82 .8 .20 2.4 .0 4.2 .0 0 4.0 8.8 .0 .0 26 54 0 8 0 40 4.4 5
YELLOW WATER BRANCH NEAR MAXVILLE-Semi-annual
Average 68 9.7 .82 9.4 2.1 8.9 1.9 84 8.9 14 .1 .4 .8 67 88 18 82 4 108 6.5 58
Maximum 76 15 .58 15 8.5 12 4.9 56 8.0 18 .2 1.7 1.1 96 114 29 50 6 154 7.1 110 Minimum 56 2.8 .21 1.6 .2 2.6 .0 8 1.2 4.5 .1 .0 .0 14 85 2 5 2 26 5.5 10
NORTH FORK BLACK CREEK NEAR MIDDLEBURG-6-8 week intervals
Average 62 7.1 .87 8.6 1.8 9.8 0.5 18 28 8.4 .2 .5 66 100 84 29 18 108 6.1 175
Maximum 75 11 .68 28 8.9 20 1.9 25 96 12 .4 1.7 170 184 66 86 68 279 6.8 1,000 Minimum 48 1.1 .16 .8 .0 8.2 .0 1 .8 8.5 .1 .1 20 59 9 8 6 88 4.7 8
ATES CREEK NEAR PENNEY FARMS-Semi-annual
Average 64 5.9 .82 1.9 .6 4.4 .1 8 1.7 7. .2 .2 .6 24 50 25 7 5 40 5.2 158
Maximum 76 7.9 .40 2.4 1.1 5.9 .4 5 82 10 .8 .4 1.0 81 74 45 9 55 5.6 220 Minimum 52 2.9 .24 .8 2.7 .0 1 .5 4.5 .1 .1 .4 14 80 8 4 2 27 4.7. .80
GREEN'S CREEK NEAR PENNEY FARMS-Semi-annual
Average 68 7.9 .28 4.9 .7 5.6 .1 18 1.0610 .1 .1 .1 87 60 25 15 4 60 0.1 82
Maximum 74 11 .27 9.2 1.6 7.0 .4 27 1.8 14 .2 .4 2 48 78 26 26 6 80 6.8 110 Minimum 49 2.6 .17 1.6 .0 8.0 .0 0 .4 4.2 .1 .0 .0 12 86 24 4 2 81 4.7 60
BULL CREEK NEAR MIDDLEBURG--Semi-annual
Average 61 6.4 .28 4.8 1.5 8.8 .4 15 8.8 6.8 .2 .0 .8 85 57 26 17 4 52 6.8 126
Maximum 74 7.8 .25 7.6 2.2 '4.6 1.0 81 5.0 9.0 .2 .1 .5 49 64 85 28 7 70 7.0 200
Minimum 51 8.1 .21 1.6 .6 2.0 .0 2 1.6 4.0 .2 .0 .2 18 58 21 6 2 80' 5.1 70
nSeri-annual July 1967 to September 1958, Daily October 1958 to September 19509, 6.8 week intervals October 1959 to September 1960.




TABLE 5, (CONTINuED),
Hardnesse C.
as CaCO 0
0 64
SOUTH FORK BLACK CREEK NEAR PENNEY FARMS
Averge 60 6.4 0.80 8.8 0.9 4.8 0.8 11 2.7 7.4 0.2 0.2 81 58 27 18 4 51 6.1 185
Maximum 82 18 .84 84 8.2 7.2 .7 90 22 12 .4 8.4 127 156 I57 98 80 228 7.5 860 Minimum 50 1.4 .17 1.0 .1 1.8 .0 4 .0 8.0 .0 .0 12 28 8 8 0 18 5.8 10
DEEP CREEK NEAR RODMAN-Semi-annual
Average 64 10 .17 15 4.9 8.4 .6 64 8.0 6.5 .2 .0 .2 75 91 16 58 6 124 7.2 98 Maximum 74 17 .24 19 6.2 8.8 1.6 87 6.0 6.5 .8 .1 .8 90 104 89 78 10 154 7.6 190 Minimum 57 4.5 .11 6.2 2.1 8.1 .1 20 .8 4.5 .1 .0 .0 82 71 4 24 2 56 6.7 85
SOUTH FORK BLACK CREEK NEAR CAMP BLANDING S. R. 21
8/18/59 56 2.9 .14 5.8 .9 4.4 .0 12 8.6 7.0 .2 .0 81 46 15 18 8 62 6.5 50
CLARKS CREEK NEAR GREEN COVE SPRINGS
6. 3.o o 87 60 65 a 8 g 0o 73 1 14o: 9
9/80/58 11 11 .7 6.2 35 2.2 9.0 .2 .0 .2 58 - 80 2 87 7.1 80
4Daily October 1958 to September 1959, 6-8 week intervals July 1957 to September 1958 and October 1959 to September 1960.




PETERS CREEK NEAR PENNEY FARMS
9/80/58 8.8 6.0 .6 4.8 .20 0.5 7.5 .2 .0 .8 89 18 1 58 6.8 40
BOGGY BRANCH NEAR CAMP BLANDING
12/17/57 6.6 .18 2.8 1.5 4.2 .0 7 8.5 9.0 .1 .1 .8 81 64 88 18 8 49 6. 120
8/18/58 62 5.1 .08 2.6 1.0 5.4 .5 8 2.5 9.0 .2 .8 28 71 48 10 8 58 5.0 180
NORTH FORK BLACK CREEK UPSTREAM FROM CONFLUENCE OF BOGGY BRANCH 12/17 /57 10 .10 18 4.7 20 .4 0 118 8.5 .2 .7 .0 172 190 18 52 52 288 4.4 80 8/18/58 8.0 .24 14 2.4 s .8 2 105 8.2 .1 .7 .. 176 198 22 45 44 808 5.0 20




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PAGE 1

STATE OF FLORIDA STATE BOARD OF CONSERVATION DIVISION OF GEOLOGY FLORIDA GEOLOGICAL SURVEY Robert O. Vernon, Director REPORT OF INVESTIGATIONS NO. 35 WATER RESOURCES OF ALACHUA, BRADFORD, CLAY, AND UNION COUNTIES, FLORIDA By WILLIAM E. CLARK, RUFUS H. MUSGROVE, CLARENCE G. MENKE, AND JOSEPH W. CAGLE, JR. Prepared by the UNITED STATES GEOLOGICAL SURVEY in cooperation with the FLORIDA GEOLOGICAL SURVEY TALLAHASSEE Tallahassee 1964

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'4oQ, Y /'A .zý AGRI. CULTRJ FLORIDA STATE BOW!td OF CONSERVATION FARRIS BRYANT Governor TOM ADAMS RICHARD ERVIN Secretary of State Attorney General J. EDWIN LARSON RAY E. GREEN Treasurer Comptroller THOMAS D. BAILEY DOYLE CONNER Superintendent of Public Instruction Commissioner of Agriculture W. RANDOLPH HODGES Director ii

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LETTER OF TRANSMITTAL §Jioria geoloqijcal Survey Callakassee October 10, 1963 Honorable Farris Bryant, Chairman Florida State Board of Conservation Tallahassee, Florida Dear Governor Bryant: The Division of Geology is publishing as Florida Geological Survey Report of Investigations No. 35, a comprehensive report on the water resources of Alachua, Bradford, Clay, and Union counties, Florida, which was prepared by William E. Clark, R. H. Musgrove, Clarence G. Menke and Joseph W. Cagle, Jr., as part of a cooperative program with this department. These counties include one of the high pressure areas hn the artesian system of Florida, and the study permits, for the first time, when combined with studies being made in St. Johns, Flagler, and Putnam counties to the east, the observation of important portions of the ground-water cycle, ranging from recharge under water table conditions through recharge to the artesian system, movements toward the coast and discharge along the coast. It also permits the observation of changes in the distribution of pressures of such a system with the use of water along the coastal areas. We are pleased to publish this timely information. Respectfully yours, Robert O. Vernon Director and State Geologist 111

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Completed manuscript received May 9, 1963 Published for the Florida Geological Survey By The E. O. Painter Printing Company DeLand, Florida Tallahassee 1964 iv

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CONTENTS Abstract ___ 1 Introduction -_________ 4 1Purpose and scope. --._--___ _ 4 Previous investigations 6 ,Methods of investigation ______ _7 Description of area _---__________ 9 Topography _----( Geology ___ 11 Eocene Series --___ 12 Oligocene Series ________ 20 Miocene Series _____ 21 Miocene to Pleistocene (?) Series __ 23 Pleistocene Series __ ____ 24. Pleistocene and Recent Series _____ _ _ 26 Structure ____ ____ 27 Climate _______ _ 28 Temperature __~_-___28 Rainfall _ 30 Surface water c___ St. Johns River -__-.____ ___ 37 Black Creek basin _ __ _____ 38 Santa Fe River basin _____50 Orange Creek basin -_ 56 Etonia Creek basin ___ 60 Quality of surface waters_______ 65 Introduction 65 Explanation of terms ____ 75 Water temperature ___ 76 Factors affecting chemical quality __ 77 Santa Fe River basin ____ 88 Black Creek basin ____----_____ 93 North Fork Black Creek _____93 South Fork Black Creek 95 Etonia Creek basin _____ 99 Orange Creek basin ____. -_ 99 Ground water __-___ __ _ 102 Limitations of -yield_ __ ____103 Upper aquifers _-__ -110 Water-table aquifer 110 Configuration of water table _ 112 Recharge and discharge 113 Fluctuation of the water table -113 Wells __ 115 Secondary artesian aquifers __115 Piezometric surfaces __115 Fluctuation of the piezometric surfaces 117 Movement ____ __ 118 -V

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Wells 118 Floridan aquifer 120 Hydraulic properties _ __ 120 Piezometric surface -_ 122 Recharge ) Discharge __ 126 Discussion of Floridan aquifer by counties _ _ 127 Alachua County __--_ 127 Fluctuation of piezometric surface ___--127 Area of artesian flow _ _127 Analysis of pumping test ___127 Specific capacities of wells _ __ 131 Bradford County 134 Fluctuation of piezometric surface _ 134 Specific capacities of wells __ 134 Clay County 134 Fluctuation of piezometric surface 134 Area of artesian flow _ _ 134 Specific capacities of wells __ ____ 134 Union County --_ --_-_ 137 Fluctuation of piezometric surface ______ 137 Specific capacities of wells _____ _ 137 Quality of ground water -----__ _____ 138 Factors affecting chemical quality 139 Water-table aquifer 139 Secondary artesian aquifer 145 Floridan aquifer -__________ 147 Variability of water quality ___ 148 Ground-water temperature _____ __ 151 Water use -__ ________152 Relation of water quality to water use 152 Domestic use and public supplies ___ 153 Agricultural use _____ 155 Industrial use ____ ____ 157 Surface water -_________________159 Ground water _______________160 Summary _______ 162 References __ _______ 166 ILLUSTRATIONS Figure Page 1 Florida showing the locations of Alachua, Bradford, Clay, and Union counties --__ _ _ 5 2 Alachua, Bradford, Clay, and Union counties, Florida, showing the location of wells --___ facing 8 3 Explanation of well-numbering system _ _ 9 4 Generalized geologic map of Alachua, Bradford, Clay, and Union counties, Florida showing the approximate elevation of the top of the Ocala Group and the locations of geologic sections __ Facing 12 vi

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5 West-east geologic section in Alachua, Bradford, and Clay counties, Florida, along line A-A' in figure 4 __ 13 6 West-east geologic section in Alachua, Bradford, and Clay counties, Florida, along line B-B' in figure 4 ___ -14 7 Southwest-northwest geologic section in Alachua and Union counties, Florida, along line C-C' in figure 4 15 8 South-north geologic section in Alachua, Bradford, and Union counties, Florida, along line D-D' in figure 4 __ __ 16 9 South-north geologic section in Alachua, Clay, and Bradford counties, Florida along line E-E' in figure 4 17 10 Monthly mean temperatures 1912-1960,-at Gainesville, Florida 29 11 Rainfall at Gainesville, Florida, for the period 1900-60 30 12 Flow chart showing average flow of streams in Alachua, Bradford, Clay, and Union counties, Florida ___ ---_----_-------------____ 36 13 Drainage map of the Black Creek basin showing data collection sites _ __ ____ 38 14 Channel-bottom profiles of streams in the Black Creek basin _ 40 15 Average runoff in inches per year from areas within the Black Creek basin ---____..._______-__-_.-__...---. 41 16 Rainfall-runoff relation 42 17 Flow-duration curves for streams in the Black Creek basin _ 44 18 Discharge available without storage for South Fork Black Creek near Penney Farms, -Florida (1939-60) --__-_------______.. 45 19 Discharge available without storage for North Fork Black Creek near Middleburg, Florida (1932-60) 45 20 Hydrographs of floods during May 20-25, 1959, in the Black Creek basin _____------_ ____ 46 21 Flood frequency curves for the Black Creek basin 47 22 Depth contours of Whitmore Lake 48 23 Stage duration curve for Kingsley Lake (1947-60) 49 24 Depth contours of Kingsley Lake _____ 50 25 Drainage map of the Santa Fe River basin showing data collection sites 51 26 Average runoff in inches per year from areas within the Santa Fe River basin 52 27 Flow hydrographs for the Santa Fe River _ 53 28 Flow-duration curves for streams in the Santa Fe River basin __ 55 29 Stage graphs of Santa Fe Lake, Lake Sampson, and Lake Butler 56 30 Drainage map of the Orange Creek basin showing data collection sites _--. -57 31 Flow-duration curves for streams in the Orange Creek basin _ 59 32 Stage-duration curves for Newnans Lake, Orange Lake, and Lochloosa Lake _____ 61 33 Stage graphs for Newnans Lake _____ 62 34 Stage graphs for Orange Lake 62. 35 Stage graphs for Lochloosa Lake 63 36 Drainage map of the Etonia Creek basin showing data collection sites ____ ----4 64 37 Depth contours of Blue Pond _ 65 38 Depth contours of Sand Hill Lake ---66 39 Depth contours of Magnolia Lake .-._-_-___-.....---__ ___ 67 vii

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40 Depth contours of Crystal Lake _-___-__ --68 41 Depth contours of Brooklyn Lake ----69 42 Depth contours of Keystone Lake _ --------70 43 Depth contours of Lake Geneva------------71 44 Depth contours of Loch Lommond ____ 72 45 Stage graphs of nine lakes near Keystone Heights, Florida _ 73 46 Profile of lakes near Keystone Heights, Florida 74 47 Water budget of Brooklyn Lake for the period October 1957 to September 1960 __ _ 74 48 Residue on evaporation at 1800C, hardness, and organic matter in relation to specific conductance, Santa Fe River at Graham, Florida, July 1957 to September 1960 -_---. .....-..--89 49 Specific conductance in relation to flow, Santa Fe River at Graham, Florida July 1957 to September 1960 -____ 90 50 Cumulative frequency curve of specific conductance of selected streams (periodic samples) ___ _ 91 51 Cumulative frequency curve of residue of selected streams (periodic samples) ______--------92 52 Cumulative frequency curve of some of selected streams (periodic samples) --.---_---.-__--.. -_--_----_ 93 53 Cumulative frequency curve of color of selected streams (periodic samples) __--___ ____---_94 54 Residue on evaporation at 1800C, hardness, and organic matter in relation to specific conductance, New River near Lake Butler, Florida, July 1957 to September 1960 ____---95 55 Specific conductance in relation to flow, New River near Lake Butler, Florida, July 1957 to September 1960 _ --_____ 96 56 Cumulative frequency curves of selected characteristics of water from New River near Lake Butler, Florida, October 1957 to September 1958 _____ __ ____ .__....._ .. 97 57 Residue on evaporation at 1800C, hardness, and organic matter in relation to specific conductance, Santa Fe River at Worthington, Florida, July 1957 to September 1960 --_-98 58 Specific conductance in relation to flow, Santa Fe River at Worthington, Florida, July 1957 to September 1960 99 59 Cumulative frequency curves of selected characteristics of water from Santa Fe River at Worthington, Florida, October 1957 to September 1958 -100 60 Residue on evaporation at 1800C, hardness, and organic matter in relation to specific conductance, Olustee Creek near Providence, Florida, July 1957 to September 1960 _ 101 61 Specific conductance in relation to flow, Olustee Creek near Providence, Florida, July 1957 to September 1960 -----101 62 Residue on evaporation at 1800C, hardness, and organic matter in relation to specific conductance, Santa Fe River at High Springs, Florida, July 1957 to September 1960 ____ 102 63 Specific conductance in relation to flow, Santa Fe River at High Springs, Florida, July 1957 to September 1960 103 64 Cumulative frequency curves of selected characteristics of water from Santa Fe River near High Springs, Florida, October 1958 to September 1959 _____________ 104 viii

PAGE 9

65 Residue on evaporation at 1800C, hardness, and organic matter in relation to specific conductance, North Fork Black Creek near Highland, Florida, July 1957 to September 1960 -.._.-------------105 66 Residue on evaporation at 180-°C, hardness, and organic matter in relation to specific conductance, North Fork Black Creek near Middleburg, Florida, July 1957 to September 1960 106 67 Specific conductance in relation to flow, North Fork Black Creek near Highland, Florida, July 1957 to September 1960 __ -107 68 Specific conductance in relation to flow, North Fork Black Creek near Middleburg, Florida, July 1957 to September 1960 __------107 69 Cumulative frequency curves of selected characteristics of water from North Fork Black Creek near Highland, Florida, October 1958 to September 1959 _ 108 70 Residue on evaporation at 1800C, hardness, and organic matter in relation to specific conductance, South Fork Black Creek near Penney Farms, Florida, July 1957 to September 1960 ___ 109 71 Specific conductance in relation to flow, South Fork Black Creek near Penney Farms, Florida, July 1957 to September 1960 ._ 110 72 Cumulative frequency curves of selected characteristics of water from South Fork Black Creek near Penney Farms, Florida, October 1958 to September 1959 _____--_111 73 Generalized geologic section from Archer to Orange Park, Florida showing aquifers and the movement of water 112 74 Alachua, Bradford, Clay, and Union counties, Florida showing generalized contours on the water table in the water-table aquifer .. ---_ ---__-__--.-------------___ -_--_ Facing 112 75 Hydrographs of wells 946-226-1, 000-232-1, 956-208-1, and 946-202-3 _._____114 76 Geologic sections showing typical water levels in wells tapping different aquifers -__ --___ _______ ___ 116 77 Hydrograph of well 946-206-1 near Waldo, Florida 117 78 Alachua, Bradford, Clay, and Union counties, Florida showing contours on the top of the Floridan aquifer 121 79 Semilog plot of residual drawdown versus the ratio of the time since pumping started to the time since pumping stopped, showing solution for coefficient of transmissibility -___122 80 Alachua, Bradford, Clay, and Union counties, Florida showing contours on the piezometric surface of the Floridan aquifer in June 1960 __ Facing 124 81 Hydrographs of wells 927-203-1, 929-213-1, 932-231-1, 936-236-1, 941-222-2, and 946-226-2 in Alachua County, Florida 128 82 Hydrographs of wells 948-231-2 and 949-236-2, in Alachua County, Florida ________ 129 83 Southeastern Alachua County, Florida showing the approximate area of artesian flow in June 1960 __ --130 84 Graph showing theoretical drawdowns in the vicinity of a well pumping 1,000,000 gpd for selected periods 131 85 Clay County, Florida showing the decline of the piezometric surface in eastern Clay County from June 1934 to June 1960 __ 136 86 Hydrographs of wells 959-140-1, 002-142-1, 006-149-1, and 003-151-1 in Clay County, Florida --_____-_ _ ----137 ix

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87 Clay County, Florida showing the approximate area in which wells tapping the Floridan aquifer will flow, June 1960 __ _ 138 88 Hydrograph of well 007-222-1 in Union County, Florida and a graph of monthly rainfall at High -Springs, Florida 142 89 Dissolved solids and hardness of water from the water-table aquifer ______ 144 90 Dissolved solids and hardness of water from the secondary artesian aquifers _______ 146 91 Dissolved solids and hardness of water from the Floridan aquifer _ 149 92 Alachua, Bradford, Clay, and Union counties, Florida showing. centers of concentrated pumping and estimated use of ground water in 1960 _ 161 TABLES Table Page 1 Geologic formations penetrated by water wells in Alachua, Bradford, Clay, and Union counties, Florida ___ -18 2 Departure from average rainfall, in inches, at Gainesville, Florida 31 3 Locations of gaging stations, types of surface-water data collected, and periods of records _----___.. ..__ ____ _ 32 4 Maximum, minimum, and average of observed daily water temperatures of streams in Alachua, Bradford, Clay, and Union counties, Florida ___76 5 Average, maximum, and minimum values observed for substances dissolved in streams and lakes _____ _..._ .78 6 Specific capacities of wells tapping secondary artesian aquifers -9 119 7 Specific capacities of wells tapping the Floridan aquifer in Alachua County, Florida _132 8 Specific capacities of wells tapping the Floridan aquifer in Bradford County, Florida ____ 135 9 Specific capacities of wells tapping the Floridan aquifer in Clay County, Florida -_ 140 10 Specific capacities of wells tapping the Floridan aquifer in Union County, Florida _143 11 Chemical quality of water tests commonly made for purposes indicated ______ 152 12 Water-quality characteristics and their effects _____ 154 13 Suggested water-quality tolerances ___ _ 158 14 Suggested water-quality tolerance for boiler feed water 159 x-

PAGE 11

PREFACE This report was prepared by the Water Resources Division of the U. S. Geological Survey in cooperation with the Florida Geological Survey. The investigation was under the general supervision of M. I. Rorabaugh, district engineer, Ground Water Branch; A. 0. Patterson, district engineer, Surface Water Branch; and J. W. Geurin, district chemist, succeeded by K. A. MacKichan, district engineer, Quality of Water Branch, of the U. S. Geological Survey. The writers wish to express their appreciation to the citizens of Alachua, Bradford, Clay, and Union Counties for supplying data and permitting the sampling and measuring of their wells and to the well drillers for furnishing well cuttings, water-level data, and other helpful information. Thanks are due the U. S. Soil Conservation Service for its assistance in drilling a number of shallow test wells and to Dr. E. C. Pirkle, of the University of Florida, who furnished valuable geologic information. xi

PAGE 12

I C i; L o i; iP r~i 1~ il i jr: I;; ; ; .~ M a r-

PAGE 13

WATER RESOURCES OF ALACHUA, BRADFORD, CLAY, AND UNION COUNTIES, FLORIDA By William E. Clark, Rufus H. Musgrove, Clarence G. Menke, and Joseph W. Cagle, Jr. ABSTRACT Alachua, Bradford, Clay, and Union counties are within the topographic division of Florida known as the Central Highlands, except eastern Clay County which is a part of the Coastal Lowlands. The most striking topographic features are: Trail Ridge, which extends through the area in a north-south direction; high swampy plains in the northwestern part of the area; rolling, sloping, lands that are well dissected by stream channels in the eastern part of the area; and lower, slightly rolling plains in southwestern Alachua County, which are devoid of stream channels but which are dotted with sinks and limerock pits. The area is underlain by a series of limestones and dolomites to depths of several thousand feet. The upper several hundred feet of these beds include the Lake City Limestone and Avon Park Limestone of Eocene age. The Ocala Group, the uppermost Eocene unit, is exposed in southern and western Alachua County, but its top is about 250 feet below sea level in eastern Clay County. In the extreme southwestern corner of Alachua County the Ocala Group is covered by about 35 feet of sands and clays of the Alachua Formation of Miocene to Pleistocene age, but in other parts of the area it is overlain by as much as 250 feet of relatively impervious beds of clay, sandy clay, and limestone of the Hawthorn Formation of Miocene age and by deposits of late Miocene age. In southwestern Clay County and southeastern Bradford County the Miocene deposits are beneath about 90 feet of sand and clayey sand that comprise the unnamed coarse clastics of Pleistocene age. Elsewhere within the area, the Miocene deposits are overlain by a series of higher terrace deposits of Pleistocene age and by a series of lower terrace deposits of Pleistocene and Recent age. The higher terraces are made up of the older Pleistocene terrace de-

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2 FLORIDA GEOLOGICAL SURVEY posits which form most of the land surface in Bradford and Union counties and extensive areas in Alachua and Clay counties. The thickness of the older Pleistocene terrace deposits generally is 40 feet or less, but in some places it is as much as 130 feet. Pleistocene and Recent sand, clay, and marl deposits cover older beds to depths ranging generally up to 60 feet in Clay County. The principal structure of the area is the Ocala uplift, whose crest transverses southwestern Alachua County. The regional dip of formations on the flank of the uplift is east-northeast at an average rate of about 6 feet per mile. The average annual temperature at Gainesville is 700F. Only rarely does the temperature reach 100°F and only occasionally does it drop into the teens. In fact, 280 frost-free days per year can be expected. Uneven distribution of rainfall causes most of the water problems in the area. On the average, the area receives 52 inches of rainfall per year. However, there have been considerable variations from the average which have caused both floods and droughts. Minor seasonal floods are a common occurrence. The greatest floods of record occurred in 1948-49. For the 6-year period ending in 1949 the excess rainfall at Gainesville was 45.87 inches. The most severe drought of record occurred during 1954-57. Rainfall at Gainesville was deficient by 22.66 inches during 195456. Many of the streams reached their lowest flow of record and several lakes lost most of their water during 1954-57. Orange Lake in southern Alachua County was reduced to one-fifth of its normal size, and Brooklyn Lake at Keystone Heights was reduced to one-half of its normal size. The average streamflow from the four counties is approximately 1,150 mgd (million gallons per day) and leaves the area through four stream basins that originate within the area (Black Creek, Santa Fe River, Orange Creek, and Etonia Creek). In addition, the St. Johns River, the largest and longest river wholly within Florida, flows northward along the eastern boundary of Clay County and has an average flow of about 4,500 mgd at Green Cove Springs. Average runoff from the four counties is about 12 inches per year but varies considerably from area to area. Average yearly runoff from the Black Creek basin is 14.8 inches; from the Santa Fe River basin, 22 inches; from the Orange Creek basin, 5 inches; and from Etonia Creek basin, less than 5 inches. An intervening segment of the Santa Fe River drainage area west of High Springs

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REPORT OF INVESTIGATIONS NO. 35 3 has an average runoff of 85 inches per year, which is possibly the highest runoff from any area in Florida. There are more than 50 lakes in the four counties that exceed 0.02 square mile in size, the largest of which is 25.7 square miles in size. The combined area of all these lakes is about 90 square miles. The elevations above sea level of the lakes range from 57 feet for the lowest to 176 feet for the highest. Stages of some lakes have fluctuated as much as 20 feet; others have fluctuated only 3.5 feet. Soundings have been made in 9 lakes, the deepest of which, Kingsley Lake, has a depth of 85 feet. The depths of most of the lakes are in the range from 20 to 40 feet. Concentration of substances dissolved in surface water ranged from 10 to 299 ppm (parts per million). All surface water, except in the Etonia Creek basin in southwestern Clay County, is colored. The color intensity ranged from 0 to 1,000 platinum-cobalt scale units. Except for the New River near Lake Butler and Santa Fe River at High Springs, the surface water is characteristically soft. Generally, the hardness (as calcium carbonate) is less than 50 ppm. The two major sources of ground-water supplies in these counties are the upper aquifers and the Floridan aquifer. The upper aquifers are above the Floridan aquifer except where they are absent in southern and western Alachua County. The upper aquifers are composed of a water-table aquifer and secondary artesian aquifers. The water-table aquifer consists mostly of shallow sand or clayey sand of Miocene, Pleistocene, and Pleistocene and Recent age. These sands, which are recharged locally by rainfall, yield water to domestic wells. The secondary artesian aquifers, which are sandwiched between the water-table aquifer and the Floridan aquifer, consist chiefly of limestone layers of the Hawthorn Formation or Choctawhatchee Formation. Probably more wells in these four counties withdraw water from secondary artesian aquifers than from any other aquifer. These aquifers supply sufficient water for domestic and livestock purposes. The source of the largest supplies of ground water is the Floridan aquifer, which consists mostly of limestones of Eocene and Oligocene age. In the area west of a line running through Gainesville in a southeast-northwest direction, water in the Floridan aquifer is under water-table conditions; and in the area east of this line the water is under artesian conditions. The piezometric surface of the Floridan aquifer is. high near the junction of the Alachua, Bradford, Clay, and Union county lines, indicating a

PAGE 16

4 FLORIDA GEOLOGICAL SURVEY recharge area. The rate of recharge in this area is estimated to Sbe at least 1.8 inches of water per year. In southern and western Alachua County where the Floridan aquifer is exposed, at least 10 inches of water per year percolates to the Floridan aquifer. The principal area of artesian flow from the Floridan aquifer includes most of northeastern Clay County and the low areas along the St. Johns River, Black Creek, and Little Black Creek. Although about 10 billion gallons of ground water were used in the four counties in 1960, it is a relatively undeveloped resource. Hundreds of millions of gallons of additional ground water a year probably can be developed at almost any place in the four counties if the development is based on sound scientific principles and adequate hydrologic data. Concentration of substances dissolved in ground water ranged from 14 to 687 ppm. Except for the water in the water-table aquifer, the ground water is characteristically moderately hard to hard. Often the hardness is greater than 100 ppm. Except for localized flat and swampy areas, the color intensity of the ground water is generally 10 or less. Iron in concentrations greater than 0.30 ppm occurs in both surface waters and ground waters. The occurrence of iron in excess of 0.30 ppm is less prevalent in water from the secondary artesian aquifers and from the Floridan aquifer than from the water-table aquifer. INTRODUCTION PURPOSE AND SCOPE Water is a valuable natural resource in Alachua, Bradford, Clay, and Union counties (fig. 1) but had been given little thought by local residents before the severe drought of 1954-57. The drought focused the attention of localofficials upon the usable water-supply limitations and the need for information concerning the water resources in the area. This attention was stimulated by the distressingly low water level of Brooklyn Lake near Keystone Heights. Local officials presented the problem to the State Legislature. The Legislature provided funds to the Florida Geological Survey for a water-resources investigation. With these funds from the Florida Geological Survey and matching funds from the Federal Government, a cooperative agreement was reached between the Florida Geological Survey and the U. S. Geological Survey to f_

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REPORT OF INVESTIGATIONS NO. 35 5 87' 86" 85* 84* 834S Ti 4 '" a i -.> >G--. «, soi <, "7o,,, ,, I29 , ' 27* o / o 00 4
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6 FLORIDA GEOLOGICAL SURVEY conduct the water-resources study. This report is to document the results of the study for public use. The investigation was designed to obtain data fundamental to solving water problems of the area. These data are to be published by the Florida Geological Survey in an Information Circular entitled "Water-Resources Data of Alachua, Bradford, Clay, and Union Counties, Florida." Special attention was directed toward the causes of the fluctuations of Brooklyn Lake during the investigation, and the results of this part of the investigation are published by the Florida Geological Survey in Report of Investigation 33, entitled "Hydrology of Brooklyn Lake Near Keystone Heights, Florida." High and low lake stages, floods, low streamflow, chemical content of waters, low artesian pressures, decreased well yields, and water temperatures are problems. Questions most frequently asked about water and water supplies are: (1) Where is a supply located? (2) How much is available? (3) What are the fluctuations of this supply? (4) What causes the fluctuations of a supply? and (5) What are the chemical and physical characteristics of the supply? All these questions are best answered by data on streamflow, lake and stream stages, areas and depths of lakes, drainage areas, wells, geology, ground-water levels, rainfall, and the physical and chemical character of water. These measurements should be made over a long period of time, to include both high-water and low-water conditions. PREVIOUS INVESTIGATIONS Records of streamflow have been collected by the U. S. Geological Survey at various points in the area since 1927. These records were published annually in a series of water-supply papers, and a summary of these records through 1950 is published in Water-Supply Paper 1304. The results of a low-flow study of streams during April and May 1956 were given in a report by Pride (1961). Pride (1958) reported on the frequency of floods in this area. Black and Brown (1951) gave information about the chemical quality of water in the area and other parts of Florida. A series of water-supply papers contain measurements of artesian pressure in several wells in northeastern Clay County. Ground-water resources and geology of the four counties were mentioned in a report by Matson and Sanford (1913). Artesian water supply, well descriptions, measurements of water levels in wells, and chemical analyses of water from wells were reported

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REPORT OF INVESTIGATIONS No. 35 7 by Sellards and Gunter (1913). Stringfield (1936) reported well locations and well descriptions, and prepared a piezometric map of the principal artesian aquifer of the Florida Peninsula. Ferguson, and others (1947) discussed some of the larger springs of Florida. A report by Cooper and others (1953) includes a general discussion of the water resources of these four counties. White (1958) relates water resources to landforms of the peninsula and makes brief references to Alachua County. The most comprehensive geological reports are those of Cooke and Mossom (1929) and Cooke (1945), both entitled "Geology of Florida," which describe the formations that crop out in the four counties and give details of their occurrence. A geological map of the surface formations accompanies each of these reports. Vernon (1951) has drawn structural maps that include Alachua, Bradford, Clay, and Union counties. A geological map by Vernon (1951), revised from the earlier map by Cooke (1945), shows the outcrop of the surface formations. Pirkle (1956) has contributed papers on the geology and physiography of Alachua County. A report by Puri (1957), describes the Ocala Group and its fossils at several quarry exposures in Alachua County and shows subsurface sections that extend across parts of the four-county area. Puri and Vernon (1959) give detailed descriptions of geologic sections and show panel diagrams of the subsurface geology in the counties. METHODS OF INVESTIGATION The surface-water investigation consisted of collecting stage records on lakes and streams; measuring the flow of streams; sounding lakes with a sonic depth recorder; and determining the limits of drainage areas. Field mapping of the surface occurrence of the geologic formations was made by using rock outcrops in roadcuts, streams, and channels; exposures in quarries and sinks; and the application of such geologic aids as vegetation, topography, and surface drainage features. The interpretation of the subsurface geology is based on a microscopic examination of the character, composition, and fossils of drill cuttings from approximately 70 wells and from studies of numerous drillers' logs of wells. IThe following data on existing wells were collected at the time the wells were canvassed; drillers' logs, water use, yield of wells, dimensions of casings, depth of wells, depth to water, and water temperature. Water samples were also collected for chemical .analyses. Figure 2 shows the locations of wells that were

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8 FLORIDA GEOLOGICAL SURVEY inventoried. Figure 3 gives an explanation of the well-numbering system and shows how a well may be located on the map by its number. A large part of the investigation was devoted to drilling and collecting data from 84 test wells. Forty-two of the tst wells were 11 incices in diameter and 50 feet or less in depth. Only geologic samples were collected from these wells. Twenty-seven of the test wells were 2 inches in diameter and were drilled near Brooklyn Lake. Twelve of the 2-inch wells, which ranged from 28 to 67 feet in depth, were drilled to obtain water-level measurements. The remaining 2-inch wells, which ranged in depth from 77 to 449 feet, were drilled to obtain water-level measurements, water temperatures, geologic samples, and water samples. Four 6-inch wells were drilled near Brooklyn Lake to obtain geologic samples, water-level measurements, and water samples. Nine 4-inch and two 8-inch wells were drilled to obtain geologic samples, water samples, water-level measurements, and water temperatures. Some of the test wells and some of the existing wells were pumped or allowed to flow to obtain information on the yield of the wells and to obtain information concerning the hydraulic characteristics of the material that the wells penetrated. In addition, the elevations of a number of the existing wells and a number of the test wells were determined with either an engineer's level or an altimeter. Water levels and water temperatures were measured periodically in a selected number of existing wells and in most of the test wells. On a few key wells, automatic water-level recorders were installed to obtain a continuous record of the water-level fluctuations. Water samples were collected and analyzed using standard methods (Rainwater and Thatcher, 1960). Samples of water for chemical analyses were taken at streamflow-measuring stations when practical. The analyses of these samples were used to estimate the quality of water at other locations. Water samples were collected preferably from wells for which well depth, depth of casing, geologic formation of materials, and elevation of the water surface in the well were known. The analyses of these samples were used to estimate the ground-water quality. DESCRIPTION OF AREA Alachua, Bradford, Clay, and Union counties are grouped together in the northern part of peninsular Florida (fig. 1). The '. ; .

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S45 40 35' 30 ' 25 20' ' I' 05 8200o' 55' 50' 45' 40' 35 81 ' IEXPLANATION * .2 __2 --_ DUVAL._ I COUNTYInventoried well ond number -C AY CO NT --RANE Shallow test well BAKECOUNTY--BA K IB COKNTY Deep test well topping U COUNTY -the Floridan aquifer Crek I 2J T 1 I _~ I2 _ a, I [ _ , 21 1 __ _4I LGREENi I jl l 112 I i :r'7 1'·' 1 I1 I 13 e A i • Is _ '7?' ? .r \1'TT >' _2 -T. 2 A 2B _o 2] O, 82S00 _ _ _ _ _ __ .1 2-" , -KIN AA Y i s.i 1 @*2 0 2...... ... .Hih 47*2I7 j i^ pT ; Y Y : aLe roa0mI USG GS tooaoq ph.c qu adran'gles 0 I 2 4 .5 ,Omwles the location of wells. If_.[ 20 L%J3 -IJ-Isr 2 I I ar C, n, FL ho the Doa of w .0 .J~~ ScC ýNOPY .7,nt op Figue 2 Alahua Brafor, Cly, nd nioncouties Flrida shwun

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REPORT OF INVESTIGATIONS No. 35 9 Degrees of longitude wes! of Greenwich England, prime meridian 831 82° 81o 310 EXPLANATION NASSAU derived from latitude and longitude coordinates on a state-wide grid of i BAKE I-minute parallels of latitude and I/ minute meridians of longitude. The _ wells in a I-minute quadrangle ore ,., / -/ numbered consecutively in the order I 30 c inventoried. In Florida, the latitude 0\ .CLAY S -(3 and longitude prefix north and west 7-T Land the first digit of the degree Io' number are not included in the well ALACHUA number. -TNA The well-number is a composite of \.--three numbers separated by hyphens: the first number is composed of the LEVY lost digit of the degree and the two MARI L -digits of the minutes that define the latitude on the south side of the Iminute quadrangle; the second num290 ber is composed of the last digit of the degree and two digits of the 3000' minutes that define the longitude on i : : f the east side of a I-minute quad. rangle; and the third number gives the numerical order in which the well was inventoried in the I-minute quadrangle 29°45 29*28' 29+01 29030' 29027' *2 29015' 82033' 82*32' 82031' 82 30 Well number 926-230-3 \"-' l :: 29°00' 83°00' 82045' 82030' 82015' 82000' Well-number 926-230-3 was the third well inventoried in the I-minute quadrangle north of the 29026' parallel of latitude and west of the 82030' meridian of longitude. Figure 3. Explanation of well-numbering system. area is in the vicinity of latitude 29050' N., longitude 82010' W. It extends about 50 miles north-south and about 65 miles east-west. The east edge of the area is 20 miles from the Atlantic Ocean and the southwest corner is 30 miles from the Gulf of Mexico. Trade, manufacturing, mining, agricultural, and governmental operations are the main sources of income. Revenues associated with recreational activities are increasing as the potential of the area is recognized. Although no water is consumed by recreational activity, more of the lakes are being used for this purpose as the

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10 FLORIDA GEOLOGICAL SURVEY economy of the area expands. At present, the operations of municipalities, mining, and agriculture require the largest quantities of water in the area. The four counties have an area of 2,023 square miles and had a population of 103,800 in 1957. The area and the population density of the counties are: Alachua, 892 square miles, 77 persons per square mile; Clay 598 square miles, 26 persons per square mile; Bradford, 293 square miles, 41 persons per square mile; and Union, 240 square miles, 33 persons per square mile. The four counties combined have 51 persons per square mile, whereas the state as a whole has 76 persons per square mile. (The population figures are from data by the Bureau of Business and Economic Research, University of Miami, Coral Gables, Florida.) TOPOGRAPHY The area is within the topographic division of the state known as the Central Highlands, except eastern Clay County, which is in the Coastal Lowlands division (Cooke, 1945, p. 8, 10, 11). The principal topographic features of the area are: Trail Ridge, which extends through the area in a north-south direction; the high swampy plains in central, north-central, and northwestern parts of the area; the rolling, sloping lands in the eastern part of the area which are well dissected by stream channels; and the slightly rolling plain in southern and western Alachua County, which is devoid of stream channels but which is dotted with sinks and limerock pits. Train Ridge extends from the lake region in the vicinity of Keystone Heights in southwestern Clay County northward along the Bradford-Clay County line. This ridge is a series of sandhills, the highest of which (elevation 250 feet) is just south of Kingsley Lake. From the highest point, the land slopes southward and fans out into a wide area of sandhills, which is dotted with lakes, in the vicinity of Keystone Heights. Farther south, in Putnam County, the land is flat and has many shallow lakes. North of Kingsley Lake, the ridge is narrow and generally is less than a mile wide across the crest. It slopes downward slightly to about 200 feet above msl (mean sea level) at the Baker County line. East of Trail Ridge, in Clay County, the land slopes toward the St. Johns River for a distance of 20 to 25 miles. The land along the St. Johns River in this area generally is less than 10 feet above sea level. Many well-defined channels drain directly from the east

PAGE 24

REPORT OF INVESTIGATIONS NO. 35 11 side of the ridge. Some of the headwater streams of the North Fork Black Creek have channel slopes of 50 feet per mile. The west side of Trail Ridge slopes steeply, as much as 100 feet per mile, to a swampy plain. This plain extends over parts of Alachua, Bradford, and Union counties and ranges generally from 125 to 175 feet above msl. No well-defined stream channels drain the west side of the ridge; however, several streams originate in areas occupied by the swampy plain. In southern and western Alachua County the land is fairly flat but there are gently rolling hills. This area is dotted with small ponds and pits made by mining of limestone. A significant feature of this area is the absence of stream channels. GEOLOGY' Alachua, Bradford, Clay, and Union counties are underlain by several hundred feet of unconsolidated to semiconsolidated marine and nonmarine deposits of sand, clay, marl, gravel, limestone, dolomite, and dolomitic limestone. The oldest formation penetrated by water wells in the four counties is the Lake City Limestone of Eocene age. However, the Oldsmar Limestone of Eocene age, which lies below the Lake City, probably is fresh water-bearing, at least in part. The Oldsmar Limestone, at least in part, and the overlying younger formations contain fresh water, but several thousand feet of older rocks of Tertiary and Cretaceous age that lie below the Oldsmar contain highly mineralized water. Only the fresh water-bearing formations are discussed in this report. The Eocene Series comprises the Oldsmar Limestone, Lake City Limestone, Avon Park Limestone, and Ocala Group; the Oligocene Series is represented by the Suwannee Limestone; the Miocene Series comprises the Hawthorn and Choctawhatchee Formation and, in part, the Alachua Formation; the Pleistocene Series is made up of the unnamed coarse clastics, the older Pleistocene terrace deposits, and, in part, the Alachua Formation; and the Pleistocene and Recent Series is made up of the younger marine and estuarine terrace deposits. These deposits underlie a terrain that is a series of marine terraces or plains; a hill and valley, and 'The stratigraphic nomenclature used in this report conforms to the usage by Cooke (1945) with revisions by Vernon (1951) except that the Ocala Limestone is referred to as the Ocala Group. The Ocala Group, and its subdivisions as described by Puri (1953), has been adopted by the Geological Survey of Florida. The Federal Geological Survey regards the Ocala as a formation, the Ocala Limestone.

PAGE 25

12 FLORIDA GEOLOGICAL SURVEY hill and lake topography; and a limestone plain. Except for the Inglis, Williston, and Crystal River Formations that compose the Ocala Group, which is undifferentiated in this report, erosional unconformities separate each formation. A generalized geologic map (fig. 4), which is a modification of the previous geologic maps of the area by Cooke and Mossom (1929), Cooke (1945), Vernon (1951), and Purl and Vernon (1959), shows the surface occurrence of the various formations. The oldest exposed rocks are limestones of the Ocala Group, which crop out in southern and western Alachua County.The Hawthorn, Choctawhatchee, and Alachua Formations, the unnamed coarse clastics, the older Pleistocene terrace deposits, and the Pleistocene and Recent deposits are at the surface in other parts of the four-county area. Geologic sections (figs. 5, 6, 7, 8, and 9) show thickness, structure, topographic expression, and the stratigraphic position and relationship of the formations. The geologic formations penetrated by water wells in the four counties are listed in table 1, which gives a brief description of their thickness and physical character. The formations are grouped according to their geologic age and are described from oldest to youngest-that is, from the Oldsmar Limestone of Eocene age to the Pleistocene and Recent deposits. EOCENE SERIES The Oldsmar Limestone, the lowermost formation of Eocene age, lies at relatively great depths in .Alachua, Bradford, Clay, and Union counties and is not penetrated by water wells in this area. Although a few oil test wells penetrate the Oldsmar in the four counties, the data from these wells are inconclusive relative to the thickness and character of the formation. Vernon (1951, p. 87), however, describes the thickness and lithology of the Oldsmar, based on oil test wells, in Levy County which adjoins Alachua County on the southwest. Vernon states, regarding the Oldsmar, that "it is composed essentially of fragmental marine limestones, partially to completely dolomitized and containing irregular and rare lenses of chert, impregnation of gypsum and thin shale beds." The thickness of the formation in Levy County ranged from 380 to 568 feet in five test oil wells. The Oldsmar overlies the Cedar Keys Limestone of Paleocene age. The Lake City Limestone of Eocene age is the oldest formation from which supplies of fresh ground water are obtained in the area. The Lake City is nearest the surface along the crest of the Ocala uplift in southwestern Alachua County where its top was

PAGE 26

40 35" 30* 25' 20' 15 10' 05 82°00' 55' 50' 45' 40' 35' 8130' -291 DUVAL COUNTY -292 CL COUNTY .. BA K BEIt COUNTY URGI -267* % -185 CLAY COUNT Y ! ,,/ason PUTNAM COUNTY r:L5o -s0 O EXPL , ,ON Lake VWell for whic..h dril cuttiings -Z Younger marine and e-ur.e are avaioble -. terrace deposits Well for which drillers iog Is nclacble -IOder P -eistocene lerroce Ceos i Outcrop or Quarry +40 .Unnameo coarse cicahtcs -.Lmber represevis the eleveaon a feet, referred ,o rneuan se, A lachua Formaoion ---40-. Contour represents the elevoation Choctowhotcnee Formatton of the top of the Ocolo Group, r. feet referred to meane Honorn Form on teve Dashed where inferred. tnarn i Farmotl Contour inler-ýol 40 feet. A E VVOcacl Group L YLine of geologic section NThe oreas shown as ine outcop of the Choctownoicnee Formchon The cove -0 Occlo Group, Hawthorn Forrination, Alochua sediments range in thickness from 0 to MARION COUNTY Formaton, oni the unnamed coarse clashetics 15 feet Dashed line ndicates inferrea AICOUNY yT a cre covered by a veneer of sediments thoT DOosition of formatonOal boundores OU are mostly loose sands and are, for the most Mtod fied from maps oy Vernon 1951 and port, older Ple-stocene terrace ceposlts PurS and Vernon 1959 Both ofter deposits b~onket Me outcroO of the B -.. S tograoPrinc quadrangles and F -DC epoartmernt maps Figure 4. Generalized geologic map of Alachua, Bradford, Clay and Union counties, Florida, showing the approximate elevation of the Ocala Group and the location of geologic sections.

PAGE 27

A A SPLEISTOCENE AND RECENT DEPOSITS I210 B °b 1 • , 100 -F ATI N ORMAION S C I T I E S T K _600. F 0 ROL M AS T 0 N I--J w C T -000 O 2 4 6 a 10milM CA.' Figure 5. West-east geologic section in Alachua, Bradford, and Clay counties, Florida along line A-A' in figure 4.

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OLDER PLEISTOCENE PLF, TOCEE AND TERRACE DEPOSITS PLETOCENE AO I ,"Gainilllll / .\ s l 1 , C A L N -200 3 -o o -...6 " " ." 0 0 _ 1 .o a 1mies E S T 0 N E . S-600;-Figure 6. West-east geologic section in Alachua, Bradford, and Clay counties, Florida, along line B-B' in figure 4.

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G OLDER PLEISTOCENE TERRACE DEPOSITS FORMATION 200 ',,, -.PA· _ 100oHAWTHORN RK .D-,,,__i-.. OCALA GROUPWTHORN -3 oo .Y' .--.... .L I M E S T 0 N E S-4 00 L 4 .I ... .I-. CITY LLI -500 -o 2 4 A a 10mll T LI ME S TO N E ' t ' Florida along line C-C' in figure 4. _-J

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OLDOR PLEISTOCENE TERRACE DEPOSITS HAWTHORN 114 H W FM. :e .200. ; z 144 0 0 O" F 0 R MA TI 0 N -400 ____ 4 _ • ____ _ _ o u -200 ' G 0 0A V O N _ -----. 5-300 "" """ .-400 4 L n H -5"' " "-"" "" "" '" **-"" " T' 0 N IV 6 -500 ....... " , L A K E C I T Y L I M E S T 0 N ""'. -600 0 1 2 4 6 a 10miles " Figure 8. South-north geologic section in Alachua, Bradford, and Union counties, Florida along line D-D' in figure 4.

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L REPORT OF INVESTIGATIONS NO. 35 17 OLDER PLEISTOCENE TERRACE DEPOSITS UNNAMED COARSE CLASTICS SHawthorne. , / / O I l /I I1 ^ll / S1 00 oF2S~~"AWTHO~ >-FORMATION 6O C A LA G R O U P A V O N P A R K L M E ST O NE below msl, respectively. On a line from southwest to northeast S4 HAWTHORN0miles 1 -400 across the four counties-that is, from the Ocala uplift, in the direction of greatest dip of the beds-the top of the Lake City lies at about 380 to 440 feet below msl at Gainesville, at about 600 feet below msl beneath the crest of Trail Ridge at Kingsley Lake, and at about 700 feet below msl at Green Cove Springs (fig. 5, 6). The Lake City Limestone overlies older Oldsmar Limestone of Eocene age. Drill cuttings were available from only a relatively few, widely scattered wells penetrating the Lake City; therefore, the lithologic character and comppsition of the Lake City Limestone could be determined only generally. The cuttings show the formation to be composed mostly of tan, gray, and brown, hard, finely crystalline dolomite and dolomitic limestone. Included with these beds, however, are many softer layers of tan and gray, porous, fossiliferous limestone and seams of peat or lignite. The Lake City is most readily identified in drill samples with the first appearance of the Foraminifera, Dictyoconus amtericanus (Cushman). Since no water wells for which records were available were drilled through the Lake City Limestone, the thickness of the formation was not determined. The greatest penetration, 440 feet, was by well 938-221-1 at Gainesville. The Avon Park Limestone, which overlies the Lake City Limestone, is in the subsurface throughout the four counties. The stone, is in the subsurface throughout the four counties. The

PAGE 32

'TAlt 1. (U(j, ol'oic lI'olnatioHlN Jf1ionutrtoUd fly Water Wulld In Alachua, Bradford, Clay, anll Union Countie, Florida, o0 SCutlnmltuil Bystuln, Btnrl l
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REPORT OF INVESTIGATIONS NO. 35 19 Avon Park in most parts of Alachua, Bradford, and Union counties is chiefly a dark brown to tan, granular, hard, dense to porous dolomite that in places contains a few beds of cream-colored limestone. Geologic logs of representative wells in Clay County, however, show many beds of tan, gray, or cream-colored, soft to hard limestone and dolomitic limestone interlayered with the brown dolomite. Although dolomitization has altered or destroyed many of its fossils, the formation is generally fossiliferous and carries a distinctive assemblage of "cone type" Foraminifera. The Avon Park is thinnest beneath the crest and flank of the Ocala uplift in southwestern Alachua County where it is nearest the surface. At wells 936-236-1 and 938-236-3, near Newberry in southwestern Alachua County, the Avon Park has thicknesses of 100 and 110 feet, respectively. At test well 007-222-1, in Union County, the Avon Park is 143 feet thick. The Avon Park is about 210 feet thick at Gainesville and probably maintains a nearly equivalent thickness in most other parts of the four counties. The geologic sections (fig. 5, 6, 7, 8, 9) show wells (in addition to the above) that have penetrated as much as 140 feet of the formation. Limestones of the Ocala Group have been subdivided and renamed several times in recent years by different investigators. The most recent classification is that of Puri (1957) of the Florida Geological Survey, who divided the Ocala Group from oldest to youngest, into the Inglis, Williston, and Crystal River Formations. These formations are undifferentiated in this report. Limestones of the Ocala Group, the oldest exposed rocks in the area, are at the surface in southern and western Alachua County (fig. 4), but they dip beneath younger formations in other parts of Alachua County and in Bradford, Clay and Union counties. The Ocala Group unconformably overlies the Avon Park limestone. A limestone plain was formed where the Ocala Group is at the surface. In the outcrop of the Ocala Group (fig. 4), the limestone in most places is covered by a veneer of loose sands of older Pleistocene terrace deposits. In a few places, however, the outcrop of Ocala Group is covered by clayey sands and sandy clays, which are a residuum of the younger Hawthorn and Alachua Formations. The younger sediments over the limestone tend to mask irregularities in the highly eroded surface of the Ocala Group. A karst topography-which includes such features as filled and open sinks, sinkhole lakes, solution pipes, basins, and prairies-is typical of areas underlain by the Ocala Group. The upper part of the Ocala Group is mostly a soft, white to cream-colored, chalky, coquina limestone. The Ocala Group,

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20 FLORIDA GEOLOGICAL SURVEY though it is in part a coquina throughout its thickness, grades downward into alternating layers of hard and soft, tan to brown, crystalline limestone and dolomitic limestone. Younger materials consisting of sand, clay, and vertebrate fossils have filled sinks, solution pipes, and depressions in the Ocala Group. In the outcrop of the Ocala in Alachua County, sink-fill material was penetrated by well 937-223-1 to a depth of about 200 feet, which is the approximate depth to the base of the Ocala Group and by well 938-234-1 to a depth of at least 268 feet, which would be in the Avon Park Limestone. In southwestern Clay County where the Ocala Group is beneath younger sediments, well 947-202-13, apparently penetrated a deep filled sink which was caused by a collapse of limestones of Eocene age. The Ocala Group was penetrated at a depth of 420 feet, whereas, the Ocala Group would normally be penetrated at a depth of about 200 feet. Boulders and irregular masses of chert or flint are common near the top of the Ocala Group. Cavities up to 3 feet in depth are common and some cavities as much as 40 feet in depth in the limestone in western Alachua County have been reported by drillers. The Ocala Group is thinnest beneath the crest and flank of the Ocala uplift in southwestern Alachua County. At wells 936-236-1 and 938-236-3 near Newberry, the Ocala Group is 80 and 130 feet thick, respectively. In other parts of the four counties, the Ocala Group ranges in thickness from about 200 to 250 feet. In Alachua County, the Ocala Group is as much as 220 feet thick, and in Clay County the maximum thickness was logged 230 feet in well 958139-1 at Green Cove Springs, but it may be slightly thicker in the northeastern part of Clay County. The Ocala is estimated to be 230 feet thick at Starke in Bradford County, and it may be as much as 250 feet thick northwest of Starke and westward to the vicinity of well 958-217-1. At test well 007-222-1 in Union County, the Ocala was 245 feet thick and drillers' logs of wells at Raiford in eastern Union County indicate an equivalent thickness in this area. OLIGOCENE SERIES Some boulders of the Suwannee Limestone of Oligocene age were identified at the surface in western Alachua County but it was not determined if the boulders were in place. The Suwannee is in the subsurface north and northeast of Gainesville in Alachua County, in places in northwestern Alachua County, in the approximate western one-fourth of Bradford County, and in most of Union County west of Lake Butler. Available well data indicate that the

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REPORT OF INVESTIGATIONS NO. 35 21 Suwannee is absent in most other parts of these counties and that the formation is entirely absent in Clay County. The locations of wells penetrating the Suwannee that were used to prepare acontour map of the top of the Floridan aquifer are shown in figure 78. The Suwannee Limestone is a residual material, and it probably occurs only locally except in extreme northwestern Alachua County and in western Union County where it seems to be continuous in subsurface. Owing to the lithologic similarity between the Suwannee Limestone and limestones of the underlying Ocala Group, a separation of these two units is often difficult except where diagnostic fossils occur. The Suwannee is usually identified by its "cone type" foraminifers. Generally, the formation is composed of hard and soft beds of white, tan or cream-colored limestone that is dolomitic and coquinoid in part. Also, some sand and silicified layers of chert and flint are present. North and northeast of Gainesville in Alachua County the Suwannee ranges in thickness from about 30 to 50 feet, and in western Union County and southwestern Bradford County it generally ranges in thickness from 20 to 40 feet. In northwestern Alachua and extreme southern Union counties the formation probably ranges in thickness from 20 to 30 feet. MIOCENE SERIES The Hawthorn Formation, a marine deposit of Miocene age, underlies the four counties except in parts of southern and western Alachua County. The Hawthorn crops out in Alachua County in an isolated area around Micanopy and in an irregular pattern extending from Lochloosa Lake northwestward into northwestern and north-central Alachua County. The formation also crops out in southern Union County and southwestern Bradford County (fig. 4). The main body of the outcrop of the formation terminates in Alachua County along a line of low southwestward-facing hills along the edge of the plain formed by limestones of the Ocala Group. Remnants of the Hawthorn, however, have filled sinks and formed a thin mantle of sediment over the outcrop of the Ocala Group (fig. 4). Much of the outcrop of the Hawthorn Formation is in an area of relatively rugged hill and valley terrain, but in some of the area the surface is gently rolling. Most of the Hawthorn outcrop is covered by a veneer of loose sands of the older Pleistocene terrace deposits. The Hawthorn Formation overlies the Ocala Group and the Suwannee Limestone. The Hawthorn consists chiefly of thick clays and sandy clays

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22 FLORIDA GEOLOGICAL SURVEY that range in color from green to yellow and from gray to blue. Layers or lenses of sand and relatively soft white to gray limestone and sandy phosphatic limestone are interbedded with the clays. Although pebbles and grains of phosphate having a tan, amber, brown, or black color are usually -disseminated throughout the formation, the pebbles and grains of phosphate seem to be concentrated at various levels. The lower part of the Hawthorn contains beds of tan, gray, and grayish-green, dense, hard limestone and dolomitic limestone, and interlayered clays. These beds occur in approximately the eastern one-fourth of Alachua County, all of. Bradford County except the extreme southwestern part including Brooker, that part of Union County lying generally east of Lake Butler, and all of Clay County. In Alachua County, the basal limestones and clays are usually 15 to 20 feet thick; whereas in Bradford, Clay and Union counties the basal limestones are from 20 to 30 feet thick except in places in eastern Clay County where they are about 35 feet thick. The Hawthorn Formation ranges in thickness in Alachua County from a few feet where its outcrop merges with the Ocala outcrop to about 200 feet in the northeastern part of the county (sections A-A', D-D' in fig. 5, 8). The Hawthorn is as much as 160 feet thick in the vicinity of Gainesville. In most other parts of Alachua County the formation is from 60 to 120 feet thick except in the outcrop in the Micanopy area where its thickness probably does not exceed 50 feet. In Union County, west of Lake Butler, the Hawthorn is from 55 to 100 feet thick; but east of Lake Butler it apparently is thicker because 265 feet of Hawthorn was penetrated by well 004-211-3 at Raiford State Prison in extreme eastern Union_ County. In southern Bradford County, at Brooker, only 85 feet of the Hawthorn was penetrated by well 953-220-2, but in southeastern Bradford County 160 feet of Hawthorn was penetrated by test well 952-204-1. At Starke and in most of central Bradford County the formation is about 200 feet thick, but close to New River and in the northern part of Bradford County it is 225 to 250 feet thick. In Clay County along the lines of sections A-A',. B-B', and E-E' (fig. 5, 6, 9), the thickness ranges from 80 feet at well 943-202-3 in the extreme southwestern part of Clay County to 235 feet at well 958-159-1 near Kingsley Lake in west-central Clay County. In southwestern Clay County the Hawthorn, as shown by cuttings from scattered wells, has a maximum thickness of about 160 feet. Drillers logs show that the formation is as much as 250 feet thick at places in central and northeastern Clay County.

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REPORT OF INVESTIGATIONS No. 35 23 The relatively thick and impermeable Hawthorn sediments are the principal confining beds that confine water under artesian pressure in the Floridan aquifer. The Hawthorn Formation is exposed in open sinks such as the Devil's Mill Hopper near Gainesville in Alachua County and Brooks Sink near Brooker in Bradford County. In the Devil's Mill Hopper at least 115 feet of Hawthorn sediments are exposed (Cooke and Mossom 1929, p. 129). Beds of late Miocene age that crop out along the north and south forks of Black Creek in north-central Clay County (fig. 4) are referred to as the Choctawhatchee Formation in this report. The outcrop of the Choctawhatchee is covered in most places by a thin mantle of sediment of Pleistocene and Recent age. The Choctawhatchee, which overlies the Hawthorn Formation, dips beneath younger beds away from its outcrop. It is apparently continuous in the subsurface in most of Bradford County except for that part generally west and southwest of Starke and Hampton, most of Union County except south and west of test well 001-224-1, most, if not all, of Clay County, and a part of eastern Alachua County. The Choctawhatchee Formation consists mostly of yellow and cream-colored, soft, fossiliferous clay and partly indurated marl. Thin beds of sand and thin beds of limestone are interlayered with the clay and marl, and grains and pebbles of phosphate and silica are disseminated in the beds. Owing to the abundant shell (mollusks) content in some areas the name "shell marl" has been -applied to the Choctawhatchee Formation. Drill cuttings examined from representative wells show that in most areas in the four counties the shells are few in number and are only poorly preserved fragments, molds, or casts. However, the cuttings from some wells in eastern Clay County, show concentrations of well-preserved shells. The Choctawhatchee generally is 10 to 30 feet thick in the four counties. However, along geologic section A-A' (fig. 5) the formation is as much as 40 feet thick in east-central Bradford County and central Clay County. MIOCENE TO PLEISTOCENE (?) SERIES The Alachua Formation of Miocene to Pleistocene age is exposed in southwestern Alachua County where it forms low rolling sandhills over the eroded crest of the Ocala uplift (fig. 4). The formation consists, in part if not entirely, of terrestrial deposits, which in some places contain land-vertebrate fossils of various

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24 FLORIDA GEOLOGICAL SURVEY types. The Alachua, whose surface is covered in most places by a veneer of loose sands that presumably are older Pleistocene (?) terrace deposits, lies on the highly eroded surface of the Ocala Group. Sand is one of the principal components of the formation and, where the Alachua sediments are exposed in quarries, the sand is generally in the upper part of the formation. The sand is white, gray or buff except where it has been exposed and has weathered to various shades of red. Interbedded with and commonly underlying the sands are varicolored clays, sandy clays, clayey sands, and disseminated grains and pebbles of phosphate. Clays and associated vertebrate fossils of the Alachua have accumulated in many of the sinks and depressions in the underlying limestone. Siliceous limestone and flint and phosphate boulders are scattered throughout the formation. Boulders and plates of hard rock phosphate in the Alachua Formation have been quarried extensively in southwestern Alachua County. The Alachua Formation ranges in thickness from 25 to 35 feet as indicated by well logs and quarry exposures. PLEISTOCENE SERIES Clastic sediments i:_ Clay and Bradford counties that in most geologic references are placed in the Citronelle Formation of Pliocene age have recently been tentatively reclassified by the Florida Geological Survey. Puri and Vernon (1959, p. 128-129) of the Florida Geological Survey have referred to these sediments as "Unnamed coarse clastics" and have assigned them to the Pleistocene Series pending further studies by the Florida Geological Survey. These studies are expected to provide a formational name for these beds and to establish their exact stratigraphic position. The tentative nomenclature and age assigned to these beds by the Florida Geological Survey are followed in this report. The unnamed coarse clastics are exposed in southwestern Clay and southeastern Bradford counties (fig. 4). Nearly all the outcrop of the formation is covered by a veneer of sands of older Pleistocene terrace deposits. The veneer ranges in thickness from 0 to 15 feet except north of the 29050' parallel where locally it may be thicker. At the edge of the outcrop, the unnamed coarse clastics terminate abruptly or thin to extinction beneath the younger formations within a short distance. The outcrop of the deposits is in hills and lakes except where the overlying veneer of older Pleistocene terrace deposits is gently rolling. The unnamed coarse clastics overlie the Choctawhatchee Formation.

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REPORT OF INVESTIGATIONS No. 35 25 The unnamed coarse clastics are a nonfossiliferous deltaic deposit that is composed mostly of varicolored sand and clayey sand that contains quartz gravels locally. Clay or kaolin that acts as a binder is disseminated in the sands or is in thin beds. In the vicinity of Brooklyn Lake, test wells penetrated as much as 16 feet of red and yellow sandy clay in the upper part of the formation overlying the varicolored sand and clayey sand. In most of the outcrop north of Brooklyn Lake the red and yellow sediments seem to be absent and in other parts of the outcrop the sediments, where present, are chiefly clayey sands. The unnamed coarse clastics are estimated to have maximum thickness of 90 feet where the deposit underlies the higher parts of Trail Ridge, but elsewhere in its outcrop the thickness probably does not exceed 70 feet. In southwestern Clay County, the formation ranged in thickness from 22 feet at test well 945-201-2 to 67 feet at test well 948-202-4. Outside of the outcrop of the unnamed coarse clastics (fig. 4) the maximum thickness of the formation penetrated was 46 feet at test well 943-202-3. Several higher terraces, which are marine sediments that were deposited during the early interglacial stages of the Pleistocene Epoch, compose the older Pleistocene terrace deposits of this report. Cooke (1945, p. 273-281) defined these higher terraces as "Early Pleistocene Deposits" but Puri and Vernon (1959, p. 239-240) include the higher terraces with several lower (younger) terraces in the Pleistocene and Recent Series. No attempt was made to separate the higher (early) Pleistocene deposits (terraces) that are described by Cooke. The older Pleistocene terrace deposits are exposed in central and eastern Alachua County and also crop out in most of Bradford and Union counties and in western Clay County (fig. 4). The deposits overlie the Hawthorn and Choctawhatchee Formations and the unnamed coarse clastics. Older Pleistocene terrace deposits, consisting mostly of loose tan, yellow, and gray sands that range in thickness up to 15 feet, cover the older formations (except the Choctawhatchee Formation) as shown in figure 4, but the loose sands were not mapped. The older Pleistocene terrace-deposits may be divided into two lithologic units-one predominantly sand and one predominantly clay. The predominantly sand unit generally grades downward into clayey sands and is the predominant material in the nearly enclosed outcrop in central and southeastern Alachua County and eastern Bradford and western Clay counties. These sands are usually dark gray, brown, or black due to organic matter and iron-bearing compounds, but they may be tan, yellow, or various shades of gray

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26 FLORIDA GEOLOGICAL SURVEY where they have been exposed. At a few places in the vicinity of Gainesville the loose tan, yellow, and gray sands compose the entire deposit but north of Gainesville these loose sands generally are in the upper few feet of the beds above the darker colored clayey sands. In Alachua County the composite thickness of these beds ranges from about 20 to 45 feet. In eastern Bradford and western Clay counties, the sands are 80 to 100 feet thick except beneath the higher land surfaces where the maximum thickness is about 140 feet. The predominantly clay unit consists of mottled red, yellow, and gray clay and sandy clay, which is exposed in many places in Alachua, Bradford, and Union counties. It is in the upper part of a sequence of beds that is different from those already described and was the basis for mapping the older Pleistocene terrace deposits in other parts of the outcrop that are not described above. These mottled beds are mostly clay and sandy clay that range in thickness from about 5 to 12 feet. They overlie tan, cream-colored, and pink sands and clayey sands that contain layers of sandy clay and are covered by a veneer of loose tan, yellow, gray, and white sand, which is from 1 to 5 feet thick. The thickness of the composite of these sediments is generally 40 feet or less but the beds are as much as 50 feet thick in places. The sequence of beds, which includes the mottled red, yellow, and gray sediments, is interspersed with the predominant sand lithology in the outcrop in central Alachua County, but in no particular pattern. Puri and Vernon (1959, p. 128) have included a part of the older Pleistocene terrace deposits-that is, exposures at the Gainesville airport of mottled sandy clay and clayey sand-under a description of the unnamed coarse clastics. Studies currently (1961) being made by the Florida Geological Survey are expected to define more accurately the stratigraphic position and relationship of the sediments included here as the older Pleistocene terrace deposits and of the Pleistocene deposits in Florida. PLEISTOCENE AND RECENT SERIES Several lower terraces formed during the later interglacial stages of the Pleistocene Epoch are the younger marine and estuarine terrace deposits of Pleistocene and Recent age. The several lower terraces in Clay County named and referred to by Cooke (1945, p. 281-311) as "Late Pleistocene deposits" are undifferentiated in this report. The Pleistocene and Recent deposits

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REPORT OF INVESTIGATIONS NO. 35 27 are exposed over parts of western and all of eastern Clay County as a series of terraces or plains that drop successively lower eastward to the St. Johns River (fig. 4). These deposits overlie the Choctawhatchee Formation and unnamed coarse clastics and overlap the older Pleistocene terrace deposits along their contact in western Clay County. Sediments of Pleistocene and Recent age that blanket the outcrop of the Choctawhatchee Formation to depths ranging up to about 15 feet were not mapped. The Pleistocene and Recent deposits are composed chiefly of sands and clayey sands that probably contain many layers of clay, marl, and sandy clay. The sands, clays, and marls are generally dark gray, brown or black because of ferruginous minerals, disseminated organic matter, and layers of peat and muck. Beds of shell and shell marl that lie above the Choctawhatchee Formation at some places in Clay County are tentatively included as part of the Pleistocene and Recent deposits because of their stratigraphic position. Drill cuttings from s6me wells in the vicinity of Green Cove Springs in eastern Clay County indicate a concentration of shells at places in this area; but in drill cuttings from wells at Orange Park and from test well 952-147-2 south of Penney Farms, the shells are intermixed with clayey materials as a shell marl. The Pleistocene and Recent deposits average about 60 feet in thickness, but the deposits are as much as 80 feet in thickness in areas of high elevation. STRUCTURE The principal geologic structure of the area is the Ocala uplift, an anticlinal fold or arch whose crest transverses southwestern Alachua County. The folding has arched beds of Tertiary age and has brought limestones of the Ocala Group to the surface or close to the surface along the crest and flank of the uplift. The main axis of the uplift lies several miles west of Alachua County and, in general, parallels the north-south axis of the Florida Peninsula. Geologic sections A-A', B-B', C-C', D-D', and E-E' (fig. 5, 6, 7, 8, 9) extend across parts of Alachua, Bradford, Clay, and Union counties in directions generally parallel or perpendicular to the axis of the uplift. A structure contour map (fig. 4), which may be used to determine the approximate depth to the top of the Ocala Group, shows the configuration and elevation of the top of the Ocala Group. The eroded and flattened crest of the Ocala uplift lies west of the +40-foot contour (fig. 4) in southwestern Alachua County.

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28 FLORIDA GEOLOGICAL SURVEY The regional dip of the Tertiary beds on the flank of the uplift is east-northeast and averages about 6 feet per mile. Locally, however, the dip may be greater on the flanks or limbs of smaller or lesser folds on the flank of the uplift or along zones of faulting. At some places the dip of the strata decreases to form structural terraces, and where the terraces have a local dip the structure is a monocline (fig. 5). The contour map and the geologic sections show several lesser folds on the flank of the uplift that were formed probably by the same structural forces that caused the Ocala uplift. The most prominent of these lesser folds is one whose crest is in northeastern Alachua County in a triangle defined by Waldo, Melrose, and Hawthorn. The configuration of the surface of the limestone indicates that the structure is a double plunging fold that plunges to the northwest and southeast. Such buried folds or structural "highs" often have topographic expression at a land surface, forming a hill or region of relatively great relief. This fold, whose crest is at an elevation of at least 50 feet above msl, passes west and southwest for a distance of about 5 miles into a downwarp or basin-like structure whose trough is more than 130 feet lower. The northeastern flank of the fold passes into the downwarp or similar proportions in southwestern Clay County but the structure here is made more complicated by other factors. In the lake region of southwestern Clay County, as in other parts of the four counties, the structural forces that caused the folding doubtless also brought about some faulting or fracturing of the rocks. In southwestern Clay County the relatively great variation in the elevation of the top of limestones of the Ocala Group within short distances (fig. 4) is attributed in part to a slumping of the beds due to solution. The structure may also be interpreted as representing small, tight folds with steeply dipping limbs or the displacement of beds by faulting or fracturing. CLIMATE TEMPERATURE According to the records of the U. S. Weather Bureau, the average temperature at Gainesville is 70'F. Figure 10 shows, for the 49-year period 1912-60, the average of the monthly mean temperatures, the highest monthly mean temperature, and the lowest monthly mean temperature. The graph also shows the

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REPORT OF INVESTIGATIONS No. 35 29 100 90 80 so I70 60 20 S/ /EXPLANATION | 50 -E E o/ f dP maximum Eo i // --( n 40 dc b average di m u " o / r o Sminimum o '=' 30 -minimum 20 Jan Feb 1Mar Apr 11May June July Aug |Sept Oct Nov 11 Dec Figure 10. Monthly mean temperatures, 1912-60, at Gainesville, Florida. average of the daily maximum and the average of the daily minimum temperature for each month in 1960. The average of the monthly mean temperatures ranged from 58.6°F in December to 81.3°F in August. The winter temperatures are more erratic than the summer temperatures. In other words, in the winter the area has periods of balmy weather followed by short periods of freezing temperature. The difference between the average of the daily maximum and average of the daily minimum temperature in 1960 ranged from 20 to 28°F. Only rarely does the temperature reach 100°F and only occasionally does it drop into the teens. In fact, 280 frostfree days can be expected annually.

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3S FLORIDA GEOLOGICAL SURVEY RAINFALL Rainfall in the area is quite varied in both annual amounts and seasonal distribution. Figure 11 shows the variations in yearly amounts, the monthly minimums, the monthly averages, and the monthly maximums at Gainesville for the period 1900-60. The total annual rainfall at Gainesville for the period 1900-60 ranged from 32.79 to 73.30 inches. In an average year the dry season is from late October through May, the driest month being November. Monthly total rainfall varied from none in March to 19.9 inches in September. On the average the area receives over half of its annual rainfall during the 4-month period June through September. 24_ ._ „ „__ ._L___An__ N-T 22 about double that of May. The rainy season at times extends into October, but the latter part of October is usually dry. The area's rainfall occurs as two general types (1) summer rainfall which is mostly shower and thundershower activity; and (2) winter and early spring rainfall which is more the widespread general type associated with frontal activity. Most of the rain in the summer is in the form of local showers and thundershowers. It is not uncommon for 100 thundershowers per year to occur in the area. Although these thundershowers are usually of short duration, relatively large amounts of rain fall. Rainfalls in excess of 6 inches have been observed during a 6-hour period. Because most of the summer showers are local, large differences in monthly and annual totals occur during the same periods at

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REPORT OF INVESTIGATIONS NO. 35 31 different points in the area. To a large extent, however, these differences are minimized when a comparison of long-term averages is made; the maximum difference in the long-term average at three stations-Raiford, Federal Point, and Gainesville-is less than 3 inches. The average annual rainfall in the area is 52.0 inches. Extreme variations in annual rainfall totals can occur in consecutive years-the year 1953 ranks among the wettest since 1900, while 1954 ranks among the driest of record. (Dry periods are defined as those having below average rainfall and wet periods as those having above average rainfall.) Periods of several wet years or several dry years also can occur in succession. The period of 1944-49 is the wettest of record in the area, and 1954-56 is the driest. Table 2 shows the total departure from average rainfall for several periods of extreme rainfall conditions at Gainesville. TABLE 2. Departure from Average Rainfall, in Inches, At Gainesville, Florida. Period Dry periods Wet periods 1906-11 (6 years) -44.01 1914-18 (5 years) -33.72 1928-30 (3 years) +18.24 1931-34 (4 years) -25.20 1944-49 (6 years) +45.87 1954-56 (3 years) -22.66 SURFACE WATER Surface water is defined as water that can be seen on the surface of the ground, such as that in lakes, streams, canals, springs and that stored temporarily in other land depressions. In many instances surface water and ground water are closely related. Many surface-water bodies receive large quantities of water from the ground; fdr example, springs have direct connections with groundwater reservoirs. Streams and lakes can either gain or lose water by way of the ground. The relation of surface water and ground water is sometimes intricate. A lake can gain water from the water-table aquifer at certain stages and lose water to the watertable aquifer at other stages; or, gain water from the water-table aquifer and at the same time lose water directly to the deeper ground-water aquifer, if a lake bottom is penetrated by a sinkhole.

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TAIIa 3, Location Of Gaging Stations, Types of Surface Water Data Collected And PvriodM of Records, Se Drainage No, Name and location (sr, mi.) Type and period of record 1 Ates Creek near Penney Farms, Fla. 40.8 Periodic discharge, crest stages, 1057-60 2 Blue Pond near Keystone Heights, Fla. * .81 Depth, stage, 1058.60 3 Brooklyn Lake at Keystone Heulhts, Fla. * 1.00 Depth, stage, 1057-00 4 Brooklyn Lake outlet at Keystone Heights, Fla. 17.4 Occasional discharge, 1050-00 5 Bull Creek near Middleburg, Fla. 20.4 Occasional discharge, crest stages, 1057-00 6 Butler Creek near Lake Butler, Fla. 8 Occasional discharge, crest stages, 1067-00 7 Camps Canal near Rochelle, Fla. 115 Periodic discharge, 1048-52; daily stage and discharge, 1957-60 8 Clarkes Creek near Green Cove Springs, Fla. 8.8 Occasional discharge, crest stages, 1057-60 9 Cross Creek near Island Grove, Fla. ........ Occasional discharge, 1042-47 10 Deep Creek near Rodman, Fla. 54.3 Occasional discharge, crest stage, 1956-00 11 Etonia Creek near Florahome, Fla. 172 Daily stage and discharge, 1940-61 12 Glen Springs near Gainesville, Fla. ........ Occasional discharge, 1942-60 18 Governors Creek at State Road 10 near Green Cove Springs, Fla. 10.5 Occasional discharge, 1050 14 Green Cove Springs at Green Cove Springs, Fla. ........ Occasional discharge, 1020-60 15 Greens Creek near Penney Farms, Fla. 14.0 Periodic discharge, peak stags, 1057-60 16 Hatchet Creek near Gainesville, Fla. 57 Occasional discharge, peak stage 1948-60 17 Heilbronn Springs 6 mi, N.W. of Starke, Fla. ....... Occasional discharge, 1946-60 18 Hogtown Creek near Gainesville, Fla. , 15.6 Occasional discharge, peak stage, 1958-60 19 Kingsley Lake at Camp Blanding, Fla. * 2.54 Depth, stage, 1945, 1947-60 20 Lake Butler at Lake Butler, Fla. * .4 Stage, 1957-60 21 Lake Geneva at Keystone Heights, Fla. * 2.73 Depth, stage, 1957-60

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22 Lake Grandin near Interlachen, Fla., * .55 Stage, 1957-60 28 Lake Johnson near Keystone Heights, Fla. * .74 Stage, 1945-60 24 Lake Sampson near Starke, Fla. * 8.24 Stage, 1957-60 25 Little Hatchet Creek near Gainesville, FlA. 10.9 Occasional discharge, 1947, 1956 26 Little Orange Creek near Orange Springs,, Fla. 78.9 Periodic discharge, 1947-52; occasional discharge, 1956 27 Loch Lommond near Keystone Heights, Fla. ....... Depth, stage, 1959-60 28 'Lochloosa Creek at Grove Park, Fla. 84.7 Occasional discharge, 1947, 1956; periodic discharge, 1957-60 29 Lochloosa Creek near Hawthorne, Fla. 48.8 Periodic discharge, 1947-52 80 Lochloosa Lake at Lochloosa, Fla. *10.3 Stage, 1942-52, 1956-60 81 Lochloosa Lake Outlet near Lochloosa, Fla. -... Daily stage and discharge, 1946-55 32 Magnesia Springs near Hawthorne, Fla. ..... Occasional discharge, 1941-60 , 88 Magnolia Lake near Keystone Heights, Fla. * .81 Depth, stage, 1958-60 84 Magnolia Lake Outlet near Keystone Heights, Fla. 14.8 Occasional discharge, 1956-60 85 Newnans Lake near Gainesville, Fla. * 8.2 Stage, 1945-52, 1957-60 86 New River near Lake Butler, Fla. 212 Daily stage and discharge, 1950-60 37 New River near Raiford, Fla. 98.8 Occasional discharge, 1957-60 . 88 North Fork Black Creek above Boggy Branch 84.1 Occasional discharge, 1958-60 89 North Fork Black Creek near Highlands, Fla. 48.9 Daily stage and discharge, 1957-60 40 North Fork Black Creek near Middleburg, Fla. 174 Daily stage and discharge, 1931-60 41 North Fork Black Creek at State Road 16, Fla. 9.7 Occasional discharge, 1956 42 Olustee Creek at Providence, Fla. 150 Daily stage and discharge, 1957-60 48 Orange Creek at Orange Springs, Fla. 481 Daily stage and discharge, 1942-52, 1955-60 44 Orange Lake at Orange Lake, Fla. *26.7 Stage, 1945-60 45 Orange Lake Outlet near Citra, Fla. ..... Daily stage and discharge, 1946-55 46 Ortega Creek near Jacksonville, Fla. 27.8 Occasional discharge, 1956-60 47 Pebble Lake near Keystone Heights, Fla. * .01 Stage, 1945-60, 1952-58, 1954-60 ________________________________ _____________ ______________________* 0CA

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TABI(i i, (CONTINLU i), . lte Dreoait No, Nuae in lation , ,n ll.) 'ype arndl period of recirdl 48 P'o Springs near Hfigh Springs, 'li. ........ Oc) siorali discharge, 102U-O10 40 PraIrie Creek at State itoad 20 near (alinesville, ,'lu. Ill Occualoinal discharge, 1)47, 194H, 1(56(1 50 River Styx near Micanopy, Fla, ........ Occasional dlsuhurge, 11)5(-58 51 Sampson River at Sanpson, Fla. (17,8 Occasional discharge, 1057-10 52 Sand Hill Lake near Keystone Helhts, Fla. * 1.05 Depth, stage. 1957-60 53 Santa Fe Lake near Keystone Heights, Fla. * 8.05 Stage, 1)57-60 54 Santa Fe River near Fort White, Fla. 1,080 Daily stage and discharge, 1027-20, 1032-00 55 Santa Fe River near Graham, Fla. 135 Dally stage and discharge, 1057.60 56 Santa Fe River near High Springs, Fla. 950 Daily stage and discharge, 1931-60 57 Santa Fe River at O'leno State Park, Fla. ........ Occasional discharge, 1061 58 Santa Fe River at State Road 235 at Brooker, Fla. 245 Occasional discharge, 1056 60 Santa Fe River at State Road 241 near Worthington, Fla. 670 Occasional discharge, 1056 60 Santa Fe River at U. S. Highway 301 near Hampton, Fla. 115 Occasional discharge, 1956 61 Santa Fe River at Worthington, Fla, 630 Daily stage and discharge, 1931-60 62 South Fork Black Creek near Camp Blanding, Fla. 34.8 Daily stage and discharge, 1957-60 68 South Fork Black Creek near Penney Farms, Fla. 134 Daily stage and discharge, 1930-60 64 Swift Creek near Lake Butler, Fla. 27 Daily stage and discharge, 1957-60 65 Wadesboro Spring near Orange Park, Fla. ........ Occasional discharge, 1946-60 66 Water Oak Creek near Starke, Fla. 20.7 Occasional discharge, 1967-60 67 Whitmore Lake at Camp Blanding, Fla. ........ Depth, 1960 68 Worthington Springs at Worthington, Fla. ........ Occasional discharge, 1946-60 69 Yellow Water Creek at Duval-Clay Line, Fla. 61,2 Occasional discharge, 1956 70 Yellow Water Creek near Maxville, Fla. 25.7 Periodic discharge, crest stages, 1957-60 *Area of lake surface

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REPORT OF INVESTIGATIONS NO. 35 35 The extent to which this relationship affects a surface-water body depends on the rate of exchange. Each body of water has individual behavior characteristics. Rainfall is the only factor common to all water bodies that contributes to these characteristics. Most surface-water problems can be attributed to the uneven distribution of rainfall. Floods and droughts occur in unpredictable cycles that follow very closely periods of high and low rainfall. At present (1961) there is no practical method of modifying or controlling rainfall. Therefore, problems associated with floods and droughts have to be dealt with by a system of lake and stream controls. Three useful figures expressing streamflow are: figures of average flow, minimum flow, and maximum flow. The average flow of a stream is an indication of its normal flow and also serves as a guide in determining the quantity of water that is available over a long period of time from a system having dams and storage reservoirs. Minimum flow is the limiting factor in the ultimate use of a stream not having dams and storage reservoirs. Information on maximum flows is important not only in planning the use of a stream but also in determining the use of land adjoining the flood plain and in the design of river appurtenances such as bridges. Magnitudes, durations, and frequencies of low flows and high flows are useful in planning the full use of a stream. If a damaging flood or drought is of short duration and occurs at infrequent intervals, it might be economically feasible to withstand the resultant damage. Data collected at a stream-gaging station or sampling site are for a point on the stream and represent a composite of conditions in the basin above that point. Data at any other point can be estimated on the basis of station records. Table 3 gives the locations of gaging stations and types of surface-water data collected within the four counties. Topography and geology are also important factors governing the behavior of a water body. By applying hydrologic principles to these types of data, characteristics of the water resources of an area can be determined. This section of the report will answer many questions of this nature on the surface-water resources of Alachua, Bradford, Clay, and Union counties. The average streamflow from the four counties is approximately 1,150 mgd, excluding the flow of the St. Johns River. The average streamflow from Union and Bradford counties and the northern half of Alachua County which leaves the area by way of the Santa

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36 FLORIDA GEOLOGICAL SURVEY Fe River is about 710 mgd. On the average, about 97 mgd flow from southeastern Alachua County through Orange Creek. The average flow from Clay County is about 342 mgd through Black Creek and small streams draining into St. Johns River from the eastern edge of the county. The flow chart in figure 12 shows the average flow of major streams in the area. Average yearly streamflows have been as little as one-third the average flows for the periods of record and as much as 21/2 times the average flows for the pridds of record. The St. Johns River is the largest source of surface water within the four counties. It flows north along the eastern boundary of Clay County and drains about 7,000 square miles upstream from Green Cove Springs. At that point its average flow is about 4,500 mgd. The river is large enough to harbor a Navy base at Green Cove Springs. The average runoff from the area is about 12 inches per year, which is less than one-fourth the average rainfall. The average yearly rainfall is 52 inches. The portion of rainfall not accounted "N> rp.Figure 12. Flow chart showing average flow of streams in Alachua, Bradford, Clay, and Union counties, Florida.

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REPORT OF INVESTIGATIONS NO. 35 37 for as surface runoff is taken up by evaporation, transpiration, and ground-water outflow. An area of about 300 square miles in southwestern Alachua County has no surface outflow. The few small streams in that area terminate in sinkholes. Most of the rainfall on that area leaves as underground flow. There are more than 50 lakes in the four counties that exceed 0.02 square mile in size, the largest of which is 25.7 square miles in size. The combined surface area of all these lakes is about 90 square miles or more than 4 percent of the total land area. These lakes range in elevation from 57 feet above sea level for the lowest to 176 feet above sea level for the highest. The ranges of fluctuation in stage of these lakes are quite varied. Some of the lakes have only minor seasonal fluctuations in stage, as little as 3.5 feet, and others have varied in stage as much as 32 feet. The greatest known lake depth is 85 feet. ST. JOHNS RIVER The St. Johns River flows northward 250 miles from its origin in Indian River County to Jacksonville, then eastward for 25 miles to the Atlantic. It is the largest and longest river wholly within the state, and it is the third largest in the state in terms of average flow. Its drainage area is 8,000 square miles. The slope of the river is exceedingly mild. The maximum fall during floods is only 27 feet throughout the total length of 275 miles. The river flow is affected by ocean tides as far upstream as Lake George, 120 miles from the mouth, and even farther during periods of low river stages and high tides. The normal tide range at Jacksonville is about 2.0 feet and is only slightly less at Green Cove Springs in Clay County, 50 miles from the mouth of the river. The St. Johns River forms the eastern boundary of Clay County. The river in this vicinity is the collecting channel for all surface flow from Clay County and is from 1 to 3 miles wide. The flow of the St. Johns River at Green Cove Springs is estimated to be 4,500 mgd. At DeLand, 85 miles farther upstream, the average flow is 2,000 mgd. Although not a common occurrence, a reverse flow-that is, flow in an upstream direction-at the rate of 1,000 mgd has been measured at DeLand. The flow at Jacksonville reverses direction with each change of tide.

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38 FLORIDA GEOLOGICAL SURVEY BLACK CREEK BASIN Black Creek, a tributary to the St. Johns River, has a drainage area of 474 square miles. About 400 of the 598 square miles composing Clay County are drained by Black Creek. The only major part of the basin lying outside the county is the upper 74 square miles of Yellow Water Creek, a tributary from the north. The basin is about 16 miles wide and 30 miles long, the long axis lying in a north-south direction. The basin is outlined in figure 13. The r ---BLACK CREEK BASIN 1 / N= " \ / .-*^ -~ ' .< " ^ M IO O L E B U R G9 -"f S -f --41'63 1 \W SPRINGS '^N _ / A--.SPRINGS Figure 13. Drainage map of the Black Creek basin showing data-collection sites.

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REPORT OF INVESTIGATIONS NO. 35 39 two major tributaries in the basin, South Fork Black Creek and North Fork Black Creek, join at the town of Middleburg to form Black Creek. The stream then flows eastward and enters the St. Johns River about 3 miles north of Green Cove Springs. South Fork Black Creek heads in three small lakes in the Camp Blanding Military Reservation which are Stevens Lake, Whitmore Lake, and Varnes Lake. The major tributaries to the South Fork are Ates Creek, Greens Creek, and Bull Creek. North Fork Black Creek heads in Kingsley Lake, flows northward for about 14 miles where it turns sharply to the southeast. The larger tributaries enter from the west and north; the major tributary is Yellow Water Creek that heads in a high, swampy section of Duval County to the north. The topography of the basin is hilly with the highest elevation about 250 feet above msl near Kingsley Lake on the western drainage divide and the lowest is less than 5 feet above msl at the St. Johns River. Stream channels have slopes of from 5 to 30 feet per mile except in the lower reaches where the elevations are near sea level. Figure 14 shows channel-bottom profiles of streams in the Black Creek basin. Runoff within the basin varies from area to area. Topography and geology cause these variations. The average rainfall is equal for all areas within the basin. Average runoff in inches per year from areas within the basin is given in figure 15. Some of these figures were computed from short-term records and can be used only as a guide for computing runoff from ungaged areas. Runoff in inches is defined as the depth to which an area would be covered if all the water draining from it were distributed evenly over its surface. The term is used for comparing runoff to rainfall. On the average, the basin reseives 52 inches of rainfall per year. A plot of the annual rainfall at Glen St. Marys a'gainst the annual runoff for North Fork Black Creek at Middleburg is shown in figure 16. This plot is only an indication of the rainfall-runoff relation. Much of the scattering of points in this illutration is caused by variations in the amount of antecedent rainfall conditions and by uneven geographic distribution of rainfall. More runoff will result from a rain that falls on an area that is wet from a previous rain than from one that is not. There are two areas within the basin that have extremely low runoff, the headwaters of Yellow Water Creek and the headwaters of North Fork Black Creek. Yellow Water Creek heads a high, flat, swampy area. Rainon that area stands on the ground surface for long periods and evaporation, transpiration, and seepage take

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140-----· ---l1 -°---..-.. -...--------. ---"o 0o ------o-------40 ---.---------oo S-------------/--------------------o --------------------------------I----o 10-I---,0 -------------o 0 --i-----------III /, I 4 10 1 I IS 3 30 4 3 3 40 4 44 4 4 0. o 4 1 -t go ------7, I1 Figure 14. Channel-bottom profiles of streams in the Blak Creek basin. o ---.. ... -0 I __ v/' -----1, 40 " .0-ea----------i---~---------«»„ o-i----i-V l I I .«o-------------l---i--l---C-l--I--___________-------------'s 0 a 4 0 a 10 1I 14 16 I I tI 24 20 Sl O 30 I 34 I36 38 40 4E 44 46 48 CHANNEL OISTANOE PROM MOUTH, IN MILII Figure 14. Channel-bottom profiles of streams in the Black Creek basin.

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REPORT OF INVESTIGATIONS NO. 35 41 5 \\ I,, I I 25 I I -16 \ I \ /^ I -711 20' 0M15 I 5 8 Figure 15. Average runoff in inches per year from areas within the Black Creek basin. a heavy toll of water, which accounts for the low runoff of only 5 inches per year. The headwater area of North Fork Black Creek, from which the runoff is 7 inches per year as shown in figure 16, covers 9.7 square miles. About one-fourth (2.54 sq. mi.) of the area is occupied by Kingsley Lake. A large part of the potential runoff from this area evaporates from the lake surface.

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42 FLORIDA GEOLOGICAL SURVEY 90 En >80 1 En z w -j 800 w 60 o60 z z 50 z 40 -30 0 10 20 30 40 ANNUAL RUNOFF, IN INCHES (NORTH FORK BLACK CREEK AT MIDDLEBURG) Figure 16. Rainfall-runoff relation.

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REPORT OF INVESTIGATIONS No. 35 43 Runoff from the South Fork is slightly higher than that from the North Fork except during extremely wet years. The average runoff from the South Fork is about 16.0 inches per year and from the North Fork, about 13.7 inches per year. In 1955, the driest year since records began in 1932, runoff from South Fork was 5.4 inches and from North Fork, 3.9 inches. In 1948, an extremely wet year, the South Fork runoff was 30.6 inches and the North Fork runoff was 34.4 inches. Yearly average runoff from the entire basin has varied from 4.6 inches in 1955 to 33 inches in 1948. The average runoff from the basin is estimated to be 14.8 inches per year, which is 28 percent of the average rainfall of 52 inches. The remaining 37.2 inches of rainfall is taken up by evaporation, transpiration, and seepage. The average flow from the basin is 515 cfs (cubic feet per second) (333 mgd), which is equivalent to 1.08 cfs per square mile of drainage area. The South Fork contributes 225 cfs, or 1.17 cfs per square mile, and the North Fork contributes 200 cfs, or 1.01 cfs per square mile. An average flow of about 90 cfs is contributed by small tributaries below the confluence of North Fork and South Fork. Flow-duration curves for four stations in the Black Creek basin are shown in figure 17. These curves were developed using periods of records for the Penney Farms, Highland, and Camp Blanding stations, which were extended to cover the period of the Middleburg record, 1932-60. The flow-duration curves show the percent of time a specified discharge has been equaled or exceeded during the period of record. For example, in figure 18 the mean daily flow of North Fork Black Creek near Middleburg equaled or exceeded 6.8 cfs for 99 percent of the time during the period 1932-60 (10,596 days) or, on the average, less than 6.8 cfs occurred 1 percent of the time, or once in 106 days. The flowduration curves do not give any information on the continuous length of time that a specified discharge occurred. The curves given in figures 18 and 19 show the discharge available without storage for the Penney Farms and Middleburg stations, respectively. The upper curves in these illustrations show the maximum number of consecutive days and months during which the discharge was less than a given amount, and the lower curves show the lowest average discharge for the period indicated. For example, at the Middleburg station, 10 consecutive days was the longest period that the discharge was 5.5 cfs or less, and the

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44 FLORIDA GEOLOGICAL SURVEY 10 000 DRAINA GE AREA GAGING STATION SO. MI. L SOUTH FORK BLACK CREEK NEAR PENNEY FARMS, FLA. 134 000i NEAR MIDOLEBURG, FLA. I74 SNEAR CAMP BLANDING, FLA. 34.8 3,000 -..----4. NORTH FORK BLACK CREEK 3 ! NEAR HIGHLAND, FLA. 48.9 2.000 S tooo i 50 .000 ___j r I 2 5 0 2 |0 0 5 00----9 9' ZO _ ._ ____ I .___ I i __ St \ -T I I to ' * s ------, !; 001 005 0.2 05 1 2 5 10 20 30 40 50 60 70 80 90 95 9899 99.5 99.9 99.99 PERCENT OF TIME DISCHARGE EQUALED OR EXCEEDED THAT SHOWN Figure 17. Flow-duration curves for streams in the Black Creek basin.

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REPORT OF INVESTIGATIONS No. 35 45 300I TI I l 1FT i i i I 1 300 200 Itoo 80 560Maximum period .50 of deficient flow 40 30 flow for indicated -period 10I I I 1 l i S 2 3 4 5 6 7 8 10 20 1 2 3 4 5 6 89 12 Consecutive days Consecutive months Figure 18. Discharge available without storage for South Fork Black Creek near Penney Farms, Florida (1939-60). 200 I I I I 100 80 8 60 40 Maximum period L of deficient flow 20 10 o 8 6 4 -Lowest overage flow for indicated period 2 I 1 I I l I I I 1 1 I 1 1 1 1 .1 2 3 4 6 8 10 20, 1 2 3 4 6 9 12 Consecutive days Consecutive months Figure 19. Discharge available without storage for North Fork Black Creek near Middleburg, Florida (1932-60).

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46 FLORIDA GEOLOGICAL SURVEY lowest average discharge for a 10-day period was 4.6 cfs. These curves can be used advantageously for determining the adequacy of a stream for a use when a continuous flow is required. The seasonal variation of streamflow in the Black Creek basin follows the variation of rainfall. High streamflow occurs sporadically in the summer months, June through August, as a result of heavy, local thundershowers. More general rainfall, lasting for longer periods, occur in September and October and is accompanied by high streamflow. Although there has been some flood damage in the basin, there is no record of any extremely-destructive floods. However, flood damage in the past has been light because the land adjacent to streams was sparsely settled and not because of an absence of floods. Figure 20 shows four flood hydrographs for floods caused by heavy rains on May 20 and 21, 1959. The relative magnitude of floods will vary from area to area within the basin during a Soo\ -Fol BcI 3 4» e,„„_o so Ga.U _ -t G ___.-__ --_-_-,ao ---V --_...__.. . I --i e., --1. -1 -V ----~---t -'------f i ~~ 20 21 22 23 24 25 MAY 1959 Figure 20. Hydrographs of floods during May 20-25, 1959, in the Black Creek basin.

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REPORT OF INVESTIGATIONS NO. 35 47 heavy rainstorm. The flood in May 1959 inundated several county bridges and washed out road embankments along the South Fork Black Creek where the flooding was most severe. From figure 21, which shows flood-frequency curves adapted from a report by R. W. Pride (1958), U. S. Geological Survey, a peak discharge of 2,000 cfs at the gaging station on South Fork Black Creek near Camp Blanding (drainage area, 34.8 square miles) is shown to be about a 3-year flood; that is, it will occur on the average once in 3 years. And, the peak discharge of 1,760 cfs on North Fork Black Creek near Highland (drainage area, 48.9 square miles) was less than a mean annual flood. A flood of this magnitude could be expected to occur at the Highland station at a frequency of less than 1 year. Data have been collected on two of the four lakes in the basin (Whitmore Lake and Kingsley Lake). Whitmore Lake was sounded by a sonic depth recorder on May 11, 1960. From this sounding the depth-contour map, figure 22, was derived. The maximum depth found in this lake was 20 feet, with the exception of a small o 15,000 o_ ii --------------_-S10,000 8,000 -" 6,000 ----, 5,000 ----S4,000 -o _ .0 ___ ---~ o'-__ ___ ^---^ -----3000 --------0 S3,000 U,000 S2,000 ----0 -0 03 ------------J 1,000 ----------20 30 40 50 60 80 100 200 DRAINAGE AREA, IN SQUARE MILES Figure 21. Flood-frequency curves for the Black Creek basin.

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48 FLORIDA GEOLOGICAL SURVEY R. 23 E. 120 Il I X I " 0 WHITMORE LAKE ( Clay County) " 00 0 500 1000 1500 feet I "I I I *I ( l Cony 15 Date of survey: May II, 1960 14 Contour interval: 10 feet Data source: U. S. Geological Survey R. 23E. Figure 22. Depth contours of Whitmore Lake.

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REPORT OF INVESTIGATIONS NO. 35 49 _j -JJ U0 S174 ' 175 J174-r -Figure-------T-40-30-S100 90 80 70 60 50 40 30 20 10 0 PERCENT OF TIME Figure 23. Stage-duration curve for Kingsley Lake (1947-60). hole near the north shore which was made by dredging. Based on interpretations of the records from the sonic depth recorder and visual observations of the shoreline, the lake bottom is composed of sand overlain by a layer of silt and organic material. Stage records have been collected on Kingsley Lake since 1945. The total range in stage since 1945 is 3.5 feet, which is exceptionally small for a Florida lake. The surface outlet readily conveys excess flood waters from the lake to North Fork Black Creek, which prevents extremely high lake stages. The surrounding shallow ground water readily replenishes the lake, which prevents extremely low lake stages. The combination of replenishment and removal of excess accounts for the favorable balance between gain and loss of water and for the exceptionally small range in stage. A stage-duration curve for Kingsley Lake is given in figure 23. Kingsley Lake, which is 85 feet deep, is possibly the deepest lake in northern Florida (fig. 24). The lake is circular and the bottom slopes uniformly from the shoreline at about 1 foot per 50 feet to the depth of 20 feet, then slopes more gradually to a depth of about 30 feet, beyond which the slope increases to the maximum depth of 85 feet. The bottom is formed of fine sand, but rock possibly is exposed in the deepest hole. The Black Creek basin is well dissected by stream channels which carry copious quantities of water. Topography and streamflow lend themselves well to the construction of small dams and reservoirs which would be ample for recreation and conservation which would help to equalize the uneven distribution of streamflow.

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50 FLORIDA GEOLOGICAL SURVEY 0.800 W3 ft e ..n N mO 916 N 15 17 / I "/ + I Io 20\ 1 S22 23 KINGSLEY LAKE 1 / a e ses as"e s-am lo w 00 ma. -of Wm S SN* .1s~ Ciankmr 10e 000 28 1 27 .. ..--+-,-\---+ . II Date "urge: U .L " p11al 1 srr r R.23E. Figure 24. Depth contours of Kingsley Lake. SANTA FE RIVER BASIN The Santa Fe River basin covers an area of 1,440 square miles. Flow from the basin reaches the Gulf of Mexico by way of the Suwannee River. The Santa Fe River starts in Santa Fe Lake and flows generally westward, picking up flow from the tributaries, Sampson River, New River, and Olustee Creek, before the river disappears into a sinkhole at O'Ieno State Park, 5 miles north of High Springs. The river emerges abruptly from the ground after being underground for a distance of 3 miles. The entire northern boundaries of Alachua and Gilchrist counties are formed by the Santa Fe River. The basin is shown in figure 25. The hydrology of the basin is very complex. The average runoff from the basin is about 22 inches per year. However, average runoff from subareas varies from 6 to 85 inches. Figure 26 shows the wide variation in runoff. On the average the basin receives 52 inches of rainfall per year. The ratio of runoff to rainfall varies by areas from about 1/10 to more than 11/2, which is an extreme variation within an area of 1,440 square miles. Topography and geology are among the causes of the unusual runoff conditions in this basin. Major changes in streamflow characteristics occur in the vicinity of Oleno State Park. Above this point surface streams are

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SANTA FE RIVER BASIN N-I -' 4 I, .,,: , .... \S !\ "i BULER \,,. ol Fu 5 D g oj theana e R vebai n d -oe site ' i? Sr a Figure 25. Drainage map of the Santa Fe River basin showing data-collection sites. Cn

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--._ ------------7 -" -ff S85 ' ., l-. /19 " / ', ", , -, 0 5 10 I.5 MILlS Figure 26. Average runoff in inches per year from areas within the Santa Fe River basin.

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REPORT OF INVESTIGATIONS No. 35 53 prevalent throughout Union and Bradford counties and the northern part of Alachua County. The headwater tributaries along the northern boundaries of Union and Bradford counties (Olustee Creek, Swift Creek, and New River) are in a flat, swampy area. There are several lakes in these two counties that are connected to the system of streams by surface channels. Below O'leno State Park there is a noticeable absence of surface streams. The stream channel has been cut into porous limestones. Sinkholes are prevalent and springs are numerous throughout this area. From the point where the river emerges from the ground downstream to the confluence with the Suwannee River, springs are visible along the channel, usually flowing from circular pools in the banks of the river. The large pickup in streamflow in this vicinity comes from springs. The lower half of the basin is covered with a relatively thin mantle of sands overlying porous limestone. Rain on this area seeps directly into the ground or is carried by short surface channels to sinkholes. Flow characteristics above and below O'leno State Park are shown by the hydrographs in figure 27. The flow of Santa Fe River at Worthington is indicative of the hydrologic conditions above the park and the flow of Santa Fe River near Fort White is indicative of the hydrologic conditions in the lower basin. The Worthington station measures flow from the upper 630 square miles of the basin wherein surface streams receive a high rate of direct runoff, respond rapidly to rainfall, and recede rapidly to a low base flow. Streamflow at the Fort White station does not respond to rainfall as quickly, stays up for longer periods after rains, and has a much higher base flow. A comparison of extreme O .SAT. FIE RIVER OCT. NOV DEC JAN FEB MAR. APR MAY JUNE JFLY AUG SEPT NWATER YAR HITE Fir 27. Flow hydrorahs for the Santa Fe River. 200 F---t1---t---t~~--WATER YEAR 1958 Figure 27. Flow hydrographs for the Santa Fe River.

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54 FLORIDA GEOLOGICAL SURVEY flows of the two stations will also point up the difference in streamflow characteristics. At the Worthington station the average flow is 424 cfs, the maximum is 17,500 cfs, and the minimum is 0.5 cfs. At the Fort White station the average flow is 1,576 cfs, the maximum is 12,300 cfs, and the minimum is 609 cfs. An average flow of 650 cfs enters the ground at O'leno State Park. This flow comes from four streams: 130 cfs, or 20 percent, from Olustee Creek; 240 cfs, or 37 percent, from New River; 100 cfs, or 15 percent, from Sampson River; and 180 cfs, or 28 percent, from the main stem and smaller tributaries. Flow measurements made February 24, 1961, above and below the subterranean reach of channel showed a pickup in flow of 211 cfs in that 3-mile section; a flow of 574 cfs entered the ground and 785 cfs emerged from the ground. On the same day there was a pickup in flow of 160 cfs between the lower end of the subterranean reach and the High Springs gaging station on U. S. Highway 27, a channel distance of 5.5 miles; and between the High Springs and Fort White gaging stations, a channel distance of 7 miles, the pickup was 750 cfs. Flow-duration curves for seven stations in the Santa Fe River basin are given in figure 28. Three of these stations, Santa Fe River near Fort White, near High Springs, and at Worthington, have records extending as far back as 1932; records for New River near Lake Butler extend back to 1951; the other stations: Santa Fe River near Graham, Olustee Creek near Providence, and Swift Creek near Lake Butler, have only 3 years of records, 195860. For the purpose of developing these flow-duration curves, records for all the short-term stations were extended to cover the period 1932-60. Although these flow-duration curves are not frequency curves, they can be used, with fair reliability, to predict the percent of time that a given discharge will be equaled or exceeded in the future. Lakes within this basin are a major part of the water resources. There are eight lakes with surface areas of 0.4 square mile (250 acres) or larger. The largest is Santa Fe Lake with a surface area of 8.05 square miles. Other lakes in the basin are Lake Altho, Hampton Lake, Lake Sampson, Lake Rowell, Lake Crosby, Lake Butler, and Swift Creek Pond. All these lakes are tributary lakes. Records of stage have been collected on Santa Fe Lake, Lake Sampson, and Lake Butler. Stage hydrographs for these lakes are shown in figure 29. Lake Altho and Santa Fe Lake are connected and probably exhibit similar stage characteristics. Lake Rowell,

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REPORT OF INVESTIGATIONS NO. 35 55 1. SAA E RER AR FOnTEm. LA 1,00 --2 SANTA FE mER NEAR -HGH SPROS. FLA. 950 SINGTOr, FLA. 0 ----.S A EW RIVER NEAR 2t0 --LA RLER. FA. tt2 -.SANTA FE OER NEAR GRAAAA. FLA. 135 -.OLUSTEE CREEK NEAR I.0o00oo MOVENCE, A ISFLAO -SFT CREER NEAR zpoo 1'000 \ I I io~ooo IPI lii 0401 005 02 -1 2 1 It 20 3o 0 0 SO RO 70 0 so 90so 9 9 9 s ERCENT OF TOMr DISCARGE EU amsO EOm tChOe SmOWN Figure 28. Flow-duration curves for streams in the Santa Fe River basin.

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56 FLORIDA GEOLOGICAL SURVEY 144 I '___SAWTA FE LAXE W 140 -30 LAKE SAMPSON S I LAKE I I I 1957 1958 1959 1960 Figure 29. Stage graphs of Santa Fe Lake, Lake Sampson, and Lake Butler. Lake Crosby, and Lake Sampson are connected and exhibit similar stage characteristics. Lake Sampson loses water not only through its surface outlet but also through a drainage well on the western shore of the lake. Surface-water supplies within the Santa Fe River basin are one of the area's major natural resources. -Bradford and Union counties are well dissected by stream channels that carry copious quantities of water. The high base flow in the lower reaches of the basin is unparalled in the State. This is evidenced by the fact that the area of 130 square miles west of High Springs has a runoff of 85 inches per year, or more than 11/2 times the average rainfall. ORANGE CREEK BASIN The Orange Creek basin covers about 515 square miles situated in three counties: Alachua, Marion, and 'Putnam. Three large lakes (Orange Lake, Lochloosa Lake, and Newnans Lake) and their tributaries and connecting channels form the drainage system of the upper two-thirds of the basin which lies in Alachua County. A large part of the streamflow in the upper part of the basin is relegated to lake storage. The basin is shown in figure 30. Hatchet Creek, a tributary to Newnans Lake, is the headwaters of the basin. Flow from Newnans Lake reaches Orange Lake by

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REPORT OF INVESTIGATIONS NO. 35 57 r" .ORANGE CREEK BASIN Glen 30. DGA in ESViLLE ea o ar e k ____ -t__ , -_ -C (-. s.enk f0.i Figure 30. Dtainage map of Orange Creek basin showing data-collection sites. way of Prairie Creek, Camps Canal, and River Styx. Camps Canal connects Prairie Creek, the outlet channel from Newnans Lake, and River Styx, the inflow channel to Orange Lake. Orange Lake and Lochloosa Lake which are connected by Cross'Creek both have surface outlets that form Orange Creek, a tributary to the Oklawaha River. During periods of normal stages, Lochloosa Lake is from 1/2 to 3/ foot higher than Orange Lake. The combined drainage area of the two lakes above their outlets is 323 square miles. There have been extended periods of no flow from Orange and

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58 FLORIDA GEOLOGICAL SURVEY Lochloosa Lakes. Flow from Lochloosa Lake outlet ceased in May 1954. Flow from Orange Lake outlet ceased in May 1955 when the lake-surface elevation was about 55.0 feet. The levels of these lakes remained below the elevations of their outlets until 1957. There has been flow continuously throughout the period of record (194252; 1955-60) at the gaging station on Orange Creek at Orange Springs. The minimum flow there was 2.0 cfs for several days in May and June 1956. Discharge-duration curves for Orange Creek, Camps Canal, Orange Lake outlet, and Lochloosa Lake outlet are given in figure 31. The basin slopes from an elevation of 190 feet above sea level in the headwaters of Lochloosa Creek, a tributary to Lochloosa Lake, to an elevation of about 30 feet near the mouth of Orange Creek. Newnans Lake is about 9 feet higher than Orange Lake and Lochloosa Lake is from /2 to 3/4 foot higher than Orange Lake. The fall in water surface from Orange Lake to the gaging station on Orange Creek at Orange Springs is about 30 feet. Average runoff from all areas within the basin is about 5 inches per year with exception of Little Orange Creek, a tributary entering below Orange Springs, from which the average runoff is about 8 inches per year. Rainfall on the basin averages 52 inches per year. Five inches runs off as surface flow. The remainder is taken up by evaporation, transpiration, and seepage. Open lakes surfaces, from which there is maximum evaporation, cover about 10 percent of the basin. Flat, swampy areas, with luxuriant growths of vegetation, are numerous. Rain on these areas runs off very slowly, allowing evaporation and transpiration to take a heavy toll. The elevation of the piezometric surface, that is, the pressure surface of artesian ground water, is higher than ground level in the northern three-fourths of the basin and lower than ground level in the southern part of the basin. The presence of flowing springs, such as Magnesia Springs north of Lochloosa Lake, Glen Springs at Gainesville, and of several flowing wells along the northeastern shore of Lochloosa Lake, attest to this fact. However, south of Orange Lake this condition is reversed. A sinkhole on the southwest shore of Orange Lake, at the town of Orange Lake, has been known to take water from the lake for extended periods. Water leaving Orange Lake through the sinkhole, coupled with a statewide drought in 1954-57, caused the lake to be reduced from a normal surface area of 25.7 square miles to one of about 5 square miles. All lakes in the State were lowered to some extent by this extreme drought which was the most severe and widespread in the history of the State. However, Orange Lake was losing water

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REPORT OF INVESTIGATIONS No. 35 59 2.0oo ----------------------1,000 ----^ -----------------------1,000 -SORNGE CREEK AT ORANGE SPRINGS, FLA. SRcord used: Oct. 1942-Se*l 1952 Oct. 1955-StI. 1960 CAMPS CANAL NEAR ROCHELLE, FLA. S\ecord used: Oct. 1957-Spt. 1960 1 to LOOHLOoSA LAKE OUTLE ORANGE LAKE OUTLET NEAR LOCHLOOSA, FLA. AT ORANGE LAKE, FLA 1.0 0. 01 05 2 1 2 5 to 20 0 40 60 80 90 95 9 9 9s 99.9 9.9 PERCENT OF TIME DISCHARGE EQUALED OR EXCEEDED THAT SHOWN Figure 31. Flow-duration curves for streams in the Orange Creek basin.

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60 FLORIDA GEOLOGICAL SURVEY into this sinkhole at a rate of 12 mgd on November 21, 1957, which accounted for some of the lowering of Orange Lake. Data for Newnans Lake, Orange Lake, and Lochloosa Lake, are given in figures 32, 33, 34, and 35. The stage-duration curves in figure 32 show the total percent of time that a stage was equaled or exceeded during the period of record. The upper unshaded portion of the graphs in figures 33, 34, and 35 represents the highest 25 percent of recorded stages. The lower unshaded portion represents the lowest 25 percent of recordedstages. The middle shaded portion represents the range of the middle 50 percent of recorded stages. These values are indicative of excessive, deficient, and normal lake stages. ETONIA CREEK BASIN Etonia Creek, a tributary to Rice Creek, has a drainage area of about 230 square miles. Rice Creek flows into the St. Johns River north of Palatka. The upper 150 square miles of the basin contain some 100 lakes. The largest of these is Lake Geneva which has an area of 2.73 square miles. These lakes are situated in the southwestern corner of Clay County and the northwestern corner of Putnam County. Many of these lakes have no surface outlets. Some are connected by surface channels to Etonia Creek. The basin is shown in figure 36. Data have been collected on 11 lakes in this basin. The highest lake, Blue Pond, is at an elevation of 174 feet above sea level. Lake Grandin, at an elevation of 81 feet above sea level, is possibly the lowest. Eight of these lakes have been sounded: Blue Pond, Sand Hill Lake, Magnolia Lake, Crystal Lake, Brooklyn Lake, Keystone Lake, Lake Geneva, and Loch Lommond. All lakes sounded have maximum depths ranging from 25 feet for the shallowest to 47 feet for the deepest. Maps showing the depth contours of these lakes are given in figures 37 through 44. Some lakes in this area have a wide range of stage. The severe drought of 1954-57 caused Brooklyn Lake at Keystone Heights to be lowered 20 feet. Pebble Lake, a small lake in Gold Head Branch State Park, had a 32-foot range of stage during the period from 1948 to 1956. However, some lakes in the area have less than a 5-foot range of stage. Stage graphs of nine lakes are given in figure 45. The basic cause of all stage fluctuations is variations in rainfall. However, on the average, all the basin receives the same amount of rainfall, 52 inches per year. The reasons that some lakes

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REPORT OF INVESTIGATIONS No. 35 61 71 7; ---i --i --| --i --i ---------------70 69 66 66 NEWNANS LAKE Period of Record: Oct. 1946-Dec. 195E Aug. 1957-Dec. 1960 65 64 63--§ 63 S61 § LOCHLOOSA LAKE Perlod of Rocord: Jly 1942-Dec. 1952 ra \ Oct. 1956-Dec. 1960 S 7 605 40 30 Lo lORANGE LAKE Perlod of Record: Jan. 1943-Dec. 1960 54 50 50 00 80 70 60 507 40 30 20 10 0 'PERCENT OF TIME Figure 32. Stage-duration curves for Newnans Lake, Orange Lake, and Lochloosa Lake.

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62 FLORIDA GEOLOGICAL SURVEY S70 plower 25 percent 6 . I ri .,.-'. " ' .dl 5.0mlddlr 50 pircnl ..per z lower 25 percm t 6OR -.. .p. .e 63 Figure 33. State graphs for Newnane Lake. :! D E F IC IE JTj -i --I _ j lo er 25 percent I I S5756 z l P JAN. FEBMAR. APR. MAY JUN. JUL. AUG. SEP. OCT. NOV. DEC. Figure 34. Stage graphs for Orange Lake.

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REPORT OF INVESTIGATIONS No. 35 63 56 -.. .--r SEXCESSI .__ 58 JAN FEB. MAR. APR MAY JUN JUL AUG SEP OCT NOV DEC W lower 25 percent 53 JAN. FEB. MAR. APR. MAY JUN. JUL. AUG. SEP. OCT. NOV. DEC. Figure 35. Stage graphs for Lochloosa Lake. vary more than others are differences in topography and geologic formations. Topography dictates which lakes are connected by surface channels. Lakes in this basin are situated among high sandhills that are from 130 to 210 feet above sea level. These hills are as much as 70 feet above the adjacent lake surfaces. The character, composition, thickness, structure, and extent of the underlying geologic formations, and their hydrologic properties, are controlling factors in the movement of water into and out of the lake. Sands and clayey sands underlie the basin to a depth of as much as 90 feet below the surface. Most lakes are believed to be floored in these materials. The sands overlie thick, relatively impervious clays and limestones. Data have been collected on the six highest lakes that form the headwaters of Etonia Creek: Blue Pond, Sand Hill Lake, Magnolia Lake, Brooklyn Lake, Keystone Lake, and Lake Geneva. These lakes are in Clay County near the town of Keystone Heights. A profile of these lakes is given in figure 46. During the statewide drought of 1954-57 all lakes in this area receded to all-time low stages. Low stages affected the utility of Brooklyn Lake possibly more than any other lake in this immediate area. However, in 1958 the drought was broken by above-normal rains and by 1959 Brooklyn Lake was filled to overflow capacity.

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64 FLORIDA GEOLOGICAL SURVEY r\ SETONIA CREEK BASIN o * A 1 N-4J LMA ef Eata-cotlction stie; cnumbr I'L rlftr h IO sito mnmbr, Gable 3k Figure 36. Drainage map of the Etonia Creek basin showing data-collection sites. A water budget for Brooklyn Lake for the period August 1957 to October 1960 was computed by Clark, Musgrove, Menke, arid Cagle (1963). This water budget showed that 22,000 acre-feet of water entered Brooklyn Lake during that period as surface flow through the channel from Magnolia Lake and that 8,000 acre-feet of rain fell directly on the lake surface. Factors accounting for the losses of water from the lake are seepage, 11,000 acre-feet; evaporation, 7,000 acre-feet; and surface flow, 2,000 acre-feet. During this period, the amount of water stored in the lake increased 10,000 acre-feet. A schematic diagram of this water budget is given in figure 47. The report by Clark, Musgrove, Menke, and Cagle (1963) furnishes more detailed information on Brooklyn Lake and surrounding lakes. Many lakes in this area are landlocked and depend entirely on rainfall directly on the surface of the lake and seepage from ground to maintain their supply of water. Lake elevations are generally lower to the south and southeast as the land elevations of the basin become lower. However, the relative elevations of the lakes vary

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REPORT OF INVESTIGATIONS NO. 35 65 R. 23 E. 18 7 I Date of survey: Nov. 9, 1960 SData source: U. S. GeologIcal Survey R.23E. Figure 37. Depth contours of Blue Pond. locally. On January 27, 1961, the elevation of Hutchinson Lake, \ " \ BLUE POND " ---"'" a small landlocked lake immediately south of Lake Geneva, was 106.4 feet above sea level-0.8 foot higher than Lake Geneva. Runoff from this basin is extremely low. Based on 21 months 1 I ; I I I Sof sow records collected at Florahome, the estimated average, 1960 runoff from a drainage area of 172 square miles is 4 inches per year. Runoff is possibly higher in the lower part of the basin.feet Seepage to the deep ground water, evaporation frorcm lake surfaces, R.23 E. Figure 37. Depth contours of Blue Pond. loally. On January 27, 1961,o the elevation of Hutchinsthat falls on the upperLake, part of the basin. QUALITY OF SURFACE WATERS INTRODUCTION A discussion of streamfow and lake levelsly south of Lake Geneva, wasdford, 106.4 feet above sea level--0.8 foot higher than Lake Geneva. Clay, and Union counties has extremely lownted. In this secti months chemical ality of water i streamow reords collected at Florahome,s in the estimated averages is runoff from a drainage area of 172 square miles is 4 inches per year. Runoff is possibly higher in the lower part of the basin. Seepage to the deep ground water, evaporation from lake surfaces, and transpiration take most of the rain that falls on the upper part of the basin. QUALITY OF SURFACE WATERS INTRODUCTION A discussion of streamflow and lake levels in Alachua, Bradford, Clay, and Union counties has been presented. In this section the chemical quality of water in streams and lakes in those counties is

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Rt 23 E. Elaevlloe : 138.1 If obove meian 1 * level ...0 ./\--w,\--\4 29 .o 2 --,-27 so a 32 33 34 SAND HILL LAIKEI 4 (Clay County) 1000o 00000 o00P 3000 feet Date of survey: Nov. 28, 1960 Contour Interval: 10 feet t---. Dota source: U.S. Geological Survey R. 23E. Figure 38. Depth contours of Sand Hill Lake.

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R.23E. Elevation: 124.7 ft. above mean sea level / I / \\ \7: , I, I } c 0 Date of survey: Nov. 28, 1980 Contour nterval: 10 feet Data source: U.S. Geological Survey R. 23 E. Figure 39. Depth contours of Magnolia Lake.

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68 ,FLORIDA GEOLOGICAL SURVEY R22E R23E .36 31 cc 251 1 -) I 6 ,330 I , 12 1 I CRYSTAL LAKE (Clay and Bradford Counties) Date of survey: May 10, 1960 Contour interval: 10 feet Data source: U S. Geological Survey R.22E R 23 E. Fiure 40. Deth contours of Crystal Lake. I I------" CRYSTAL LAKE ( Cloy and Bradford Counties) 500 0 500 1000 1500 feet Date of survey: May 10, 1960 * Contour interval: 10 feet 1 Data source: U S. Geological Survey R22E. R.23E. Figure 40. Depth contours of Crystal Lake.

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R 22 E R 23E SElevation: 116.9 ft. above mean sea level 8 12 17 ---BROOKLYN LAKE n__ _ (Clay and Bradford Countles) -----_ 1000 0 1000 000 f ) I ..Q . t-l Date of urvey April 25, 1960 -1 -BROOKLYNure 41. Deth contours of Brooklyn Lake.LAKE (Clay and Bradford Counties) -.-. 1000 0 1000 8000 feet I a I I " to I Date of survey: April 25, 1960 1 20 21 Data source: U. S. Geological Survey R 22E. R 23E. Figure 41. Depth contours of Brooklyn Lake.

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70 FLORIDA GEOLOGICAL SURVEY R.23E. Elevation: 108.6 feet above mean sea level I S1 I \ I \ \ \ \ 1 IKEYSTONE LAKE (Clay County) 200 0 200 400 600 fetl Date of survey: April 26, 1960 Contour interval: 10 feet Data source: U. S. Geological Survey R.23E. Figure 42. Depth contours of Keystone Lake.

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R.22E. R 23E. SElevation: 102.7 ft. above mean sea level 24 19 \ 20 21 ---^-^ S ?^ ..,. __ -\ -/ \ ) 29" ' N 30 -' *Ys Zi (s 0 25 28 36 I 0 1 0\ 20 \0 feet, I j2 I I.. ..--./ .. .. .. 4 I I Si Cly and Bradford Countiescontours ke Geneva. 1000 0 1000 2000 3000 t@.I Dote of survey: April 26,27, 1960 32 Contour Intervol: 10 feel Data source: U. S. Geological Survey R.22E, R.23E. Figure 43. Depth contours of Lake Geneva.

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72 FLORIDA GEOLOGICAL SURVEY R. 23 E. I 8 9 + ,_f.,o _ % I Elevation: 95.4 feet above mean sea level -. / \ / / o I I I / i I / / I/ / / I /e / A / S I 16 I // tO/ LOCH LOMMOND (Clay County) 100 0 too100 00 300 400 I ., I I I I Date of survey: May 10, 1960 Contour intervak 10 foot Data source: U.S. Geological Survey R 23 E. Figure 44. Depth contours of Loch Lommond.

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REPORT OF INVESTIGATIONS No. 35 73 175 --^ -------------------------g^---O ------------__~ Blue Pond 170 135 Sand Hill Lake-L S130 Magnolia Lake 125 115 Brooklyn Lake 110 I-o ý Pebble Lake 105 -Lake Geneva S100 Figure 5. tage gasonnJohnson Lakeoi 95 1957 195 1959 1960 Figure 45. Stage grahs of nine lakes near Keystone HeiLoch Lommond 1957 1958 1959 1960 Figure 45. Stage graphs of nine lakes near Keystone Heights, Florida.

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74 FLORIDA GEOLOGICAL SURVEY PLAN S.PROFILE. Figure 46. Profile of lakes near Keystone Heights, Florida. Siwow WATER BUDGET Figure 47. Water budget of Brooklyn Lake for the period October 1957 to September 1960.

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REPORT OF INVESTIGATIONS No. 35 75 described. Just as the quantity of surface waters is variable, so is the quality. Both nature and man contribute to the changes in the concentration of matter dissolved in the waters of the area. Through natural actions, minerals in the crust of the earth affect the chemical content of the waters with which they come in contact. Man's use of water and land affects both the chemical and the sanitary quality. This report is concerned only with the chemical and physical quality and contains no information on sanitary aspects and suitability for use when such use is related to bacteriological quality. EXPLANATION OF TERMS Concentration is a ratio or proportion. It can be expressed in many different ways-parts per million, equivalents per million, grains per gallon, etc. The use of parts per million for expressing the results of water analyses has been so frequent that it has become conventional; however, this does not imply superiority of this ratio over other ratios for expressing quality of water. Conversion from one unit to any other unit is possible with the proper conversion factor. Because parts per million is used in this report as a means of expressing analytical results, an example of its magnitude is given. Water having a concentration of 1 ppm means that 1 million pounds of such water contains 1 pound of material dissolved in 999,999 pounds of water. The color of water is compared to that of colored discs which have been calibrated to correspond to the platinum-cobalt scale of Hazen. The unit of color is that produced by 1 milligram of platinum per liter. Residue on evaporation at 1800C is the concentration of substances dissolved in water that remain in a solid state at 180°C. The residue on evaporation at 180°C includes organic matter and mineral matter whenever both are present. Hardness of water is the property of water attributable to the presence of calcium and magnesium and is expressed as equivalent calcium carbonate. Mineral matter is the concentration of dissolved inorganic earth materials. The term organic matter refers to an estimate of the concentration of dissolved organic matter. The concentration is calculated by subtracting the mineral matter from the residue on evaporation at 1800C. The organic matter which is leached from vegetation characteristically colors natural waters. Whenever organic matter is absent, residue on evaporation at 180°C and mineral matter become synonymous.

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76 FLORIDA GEOLOGICAL SURVEY WATER TEMPERATURE The temperature of surface water generally varies with air temperature, but it is sometimes influenced by ground-water inflow and industrial activities, especially during low-flow periods. When streams and lakes receive large quantities of ground-water inflow during low-flow periods, the water temperatures tend to be higher than air temperatures during winter months and lower than air temperatures during summer months. Surface water temperatures usually are increased after the water has been used for such purposes as cooling and air conditioning. Large streams and lakes usually have small diurnal variations in water temperatures, whereas small streams may have a daily range of several degrees and may follow closely the changes in air temperatures. Large quantities of water on the earth's surface tend to moderate the air temperature. The observed water temperatures of streams and lakes investigated in Alachua, Bradford, Clay, and Union counties generally were above 450F in the winter months and less than 850F in the summer months. The observed daily water temperatures of the Santa Fe River near High Springs, which receives large quantities of ground-water inflow, ranged from 600 to 800F from October 1959 to September 1960. This water would be desirable for cooling and air conditioning. The daily water temperature of the Santa Fe River at Worthington, which is mostly all surface runoff, ranked from 410 to 84°F. from July 1957 to September 1960. Table 4 shows the maximums, minimums, and average observed TABLE 4. Maximum, Minimum, and Average of Observed Daily Water Temperatures of Streams in Alachua, Bradford, Clay and Union Counties, Florida Fahrenheit Stream Max. Min. Average 1. New River near Lake Butler, Aug. 1957-Sept. 1958 850 390 700 2. North Fork Black Creek near Highland, Oct. 1958-Sept. 1959 800 400 640 3. Santa Fe River near High Springs. Oct. 1959-Sept1960 800 600 720 4. Santa Fe River at Worthington, Sept. 1957-Sept19601 840 400 660 5. North Fork Black Creek near Penney Farms, Oct. 1958-Sept. 1959 810 500 690 IContinuous record.

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REPORT OF INVESTIGATIONS NO. 35 77 daily water temperatures of several streams in Alachua, Bradford, Clay, and Union counties. FACTORS AFFECTING. CHEMICAL QUALITY Rain as it falls to earth contains little or no dissolved matter. The mineral matter is usually limited to dissolved gases, notably nitrogen, oxygen, and carbon dioxide. In coastal areas, sodium chloride may be deposited by rainfall and windblown spray. The solvent action of water is greatly increased by the presence of carbon dioxide, absorbed from the atmosphere and from the soil, which enables it to break down nearly all minerals and form new compounds. The amount and type of mineral matter taken into solution by water depends, among other things, upon the availability of carbon dioxide for the weathering process, the nature of the minerals present, and the length of time the water is in contact with the minerals. As a stream flows from the higher to the lower regions of its drainage basin, it receives the inflow of many tributaries and a large amount of ground-water seepage. Solution of materials from the streambed is aided by scouring of the bed, reaeration at the surface, and the photosynthetic activity of aquatic growth. Differences in the geology of various regions, variations in topographic features, and climatic conditions will affect the chemical character of a surface stream at various points along its reach. Human activities such as diversions, impoundments, and the disposal of agricultural, industrial, and domestic wastes greatly affect water quality in some areas. Industrial and population expansion will play a dominant part in an ever-increasing demand on the water resources of the area. Increased use of water can logically be expected to affect the chemical quality of surface water as it is used and reused by industry, agriculture, and domestic service. Therefore the quality of water in streams can vary greatly due to many manmade and natural factors. The chemical-quality data are considered to be representative of the water quality of the streams during the period of study. To describe the general water quality and the water-quality variability of streams, the average, maximum, and minimum values of chemical constituents and physical qualities were determined for the period of July 1957 to September 1960. Table 5 is a tabulation of the average, maximum, and minimum values for the period of study.

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TAIII 5, Average, Maximum, Minimum Values Observed for SubHtances DiHsolved in Streams and ,Lakes Chemical analysee In Iprts per million, July 1957 to Septemlber 1960 except as otherwise stated Hardness V 0 as CaCO, Maximum 6.0 .0 .0 1 7.8 . Average 76 1.6 0.08 2. 1.2 7. 0.4 4 4.2 12 01 0. 82 44 1 11 62 6.7 26 Maximum 88 6.0 .0 .0 1.7 7.8 .0 1 7.6 13 .1 1.0 8 54 18 12 10 6 6.0 45 Minimum 60 .0 .06 1.4 .6 0.8 .1 2 1.0 12 .0 .0 28 83 5 9 6 59 5.8 10 LITTLE SANTA FE LAKE NEAR MELROSE-Semi-annual Average 70 2.8 3.8 1.2 0.7 .2 10 2.8 12 .1 1 34 56 22 14 6 68 6.0 58 Maximum 86 7.5 8.4 1.7 7.8 .4 25 5.0 12 .2 .2 49 72 33 28 8 92 7.1 65 Minimum 54 .4 2.0 1.0 6.0 .1 4 .0 11 .0 .0 25 42 15 9 5 56 5.4 50 HAMPTON LAKE AT HAMPTON BEACH-Semi-annual Average 68 1.8 .15 2.3 1.3 5.6 .3 2 7.4 9.6 .1 .2 30 50 22 11 9 60 5.1 27 Maximum 88 2.7 .26 8.6 1.6 6.4 .6 4 12 11 .2 .4 37 58 26 13 12 72 5.5 45 Minimum 57 1.0 .0 1.4 1.0 4. .0 1 1.0 .0. 1. .0 .0 .0 19 37 18 9 6 46 4.9 10 SANTA FE RIVER AT GRAHAM-0-8 week intervals Average 3. .38 8.3 1.9 6.2 .4 9 2.6 9.8 .2 .4 32 93 61 16 9 60 5.4 275 Maximum 8.6 .76 12 4.6 7.6 .8 44 8.8 16 .5 .7 73 188 99 49 14 20 6.4 500 Minimum .8 .18 1.2 .5 2.0 .0 0 .4 3.5 .1 .1 13 44 22 7 0 80 4.4 180

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SAMPSON LAKE AT SAMPSON CTY NEAR STARKE--Semi-annual Average 76 2.8 0.19 7.8 1.8 9.8 .1.0 11 15 8.6 0.2 0.2 0.0 61 90 31 26 16 112 6.2 93 Maximum 90 6.2 .21 9.6 3.6 15 1.6 20 24 11 .3 .5 .0 97 122 60 9 29 174 6. 20 Minimum 58 .7 .16 6.0 .5 2.2 .7 6 2.0 6.0 .1 .0 .0 37 68 16 19 8 74 5.9 15 SAMPSON RIVER AT GRAHAM-Semi-annual Average 64 3.1 .24 7.6 2.6 10 .7 18 22 8.6 ..1 64 88 24 30 1 15 6.4 78 Maximum 80 8.8 .29 12 4:4 16 1.2 1 8 1 .3 .3 101 124 39 48 22 176 1 Minimum 49 2.5 .20 4.2 .9 6.4 .1 2 4.8 6.0 .1 .0 28 67 9 14 63 5.0 35 HATCHET CREEK NEAR CONFLUENCE OF SANTA FE RIVER NEAR GRAHAM-Semi-annual Average 66 4.4 .38 8.9 1.5 8.6 .3 13 1.8 7. 1.2 .2 30 59 38 16 5 67 5.4 154 Maximum 78 9.2 .42 13 4.5 4.7 .9 55 8.5 9.5 .3 .70 76 56 51 8 115 6.9 280 Minimum 54 1.8 .26 .4 .4 2.0 .0 0 .4 2.5 .1 .0 8 42 21 2 2 29 4.3 80 ROCKY CREEK NEAR LaCROSS-Semi-annual Average 65 7.1 .82 7.4 2.8 5.6 1.5 22 0.0 12 .4 .0 64 86 32 80 12 90 6.3 101 Maximum 74 9.6 1.6 10 6.0 8.7 2.4 43 9.0 18 .4 .1 80 111 52 44 18 126 7.3 180 Minimum 55 8.4 .31 2.8 .9 2.9 .1 4 2.8 6.6 .2 .0 22 49 11 10 5 41 5.6 45 ALLIGATOR CREEK NEAR LAWTEY OFF STATE ROADS 16 AND 226-Semi-annual Average 70 4.0 0.17 13 2.0 5.0 0.9 48 8.0 5.5 .4 .3 68 70 11 40 2 106 6.4 80 Maximum 86 5.0 .28 25 3.5 7.0 1.8 95 4.0 6.5 .7 .4 101 103 2 77 0 181 7.6 10 Minimum 55 2.9 .06 1.2 .4 3.1 .0 2 2.0 4.5 .2 .2 16 36 20 4 3 30 5.3 90 WATER OAK CREEK AT STATE ROAD 25 NEAR STARKE-Semi-annual Average 68 0.4 .22 56.8 2,8 5.3 .7 25 2.0 8.8 .1 .1 47 68 21 25 4 756 6.2 97 Maximum 82 18 .23 10 7.2 0.2 1.2 62 2.8 14 .2 .2 94 110 25 54 6 143 7.0 110 Minimum 56 2.8 .21 2.0 .2 2.8 .1 4 .8 .8 .1 .0 15 86 16 6 2 31 5.6 90

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TABLE 5. (CONTINUED). HardneaeM Sasu CaCO, 0 04 LAKE BUTLER AT LAKE BUTLER-Semi-annual Average 70 2.0 .18 2.6 1.2 5.4 0.5 5 4.0 0.0 0.2 0.0 0.1 28 50 82 12 7 57 5.7 55 Maximum 94 4.8 .24 8.2 1.0 7.8 .8 7 7.2 12 .2 .2 .8 89 72 87 10 11 72 6.1 70 Minimum 00 .7 .00 2.2 .5 8.5 .1 2 .8 6.0 .0 .0 .0 19 41 22 8 2 40 5.2 40 BUTLER CREEK NEAR LAKE BUTLER-Semi-annual Average 61 2.9 .25 4.6 1.6 3.0 .2 12 2.9 8.1 .2 .4 .1 31 04 62 18 8 s6 5.2 812 Maximum 76 8.8 .80 11 4.8 6.1 .7 40 8.0 10 .8 1.0 .2 65 146 81 45 12 104 6.6 600 Minimum 55 1.9 .17 1.6 .5 2.0 .0 0 .4 4.8 .1 .1 .0 16 65 47 7 6 88 4.7 180 NEW RIVER NEAR LAKE BUTLERI Average 70 7.2 8.8 3.3 6.4 0.7 88 4.2 9.9 .8 1.5 60 104 42 86 8 99 6.8 187 Maximum 85 18 80 10 15 2.8 114 11 20 .5 7.7 150 189 78 106 10 278 7.6 460 Minimum 89 2.6 8.6 .2 2.0 .0 6 .4 8.8 .2 .0 21 64 18 18 8 88 5.8 90 SANTA FE RIVER AT WORTHINGTON-daily Average 66 7.8 6.4 2.6 6.5 .4 21 7.0 9.8 .2 .3 51 98 42 26 10 84 6.5 187 Maximum 84 21 18 7.6 18 1.8 64 22 62 .5 1.7 107 187 98 76 20 204 7.4 860 Minimum 40 1.9 3.2 .9 8.8 .0 0 .4 1.0 .0 .0 22 57 7 12 0 88 8.6 60 iDaily from July 1967 to September 1958, 6-8 week intervals October 1958 to September 1960.

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SWIFT CREEK NEAR PROVIDENCF-Semi-annual Average 64 5.6 0.86 8.2 2.0 4.2 0.2 7 2.2 8.5 0.2 0.1 0.4 80 79 49 16 10 61 5.6 198 Maximum 78 8.7 .87 4.0 8.4 6.0 .4 10 8.5 18 .8 .1 .9 40 110 70 24 16 70 6.0 250 Minimum 55 8.0 .88 1.4 .9 2.5 .0 2 .8 8.8 .2 .0 .0 16 68 87 7 6 80 4.9 160 OLUSTEE CREEK NEAR PROVIDENCE-6-8 Week intervals Average 68 5.1 .51 8.2 1.5 8.6 .8 8 1.7 7.7 .8 .5 29 84 55 14 8 48 5.5 254 Maximum 80 11 1.5 5.6 8.8 5.7 .7 20 4.0 11 .4 1.8 44 108 80 26 14 71 6.6 440 Minimum 50 1.2 .28 1.8 .2 2.0 .0 2 .0 8.5 .2 .0 16 49 81 7 2 29 4.9 120 SANTA FE RIVER AT HIGH SPRINGS2 Average 69 11 0.80 89 5.7 7.8 0.6 100 86 12 .8 .4 157 198 86 128 42 268 7.2 117 Maximum 80 20 .56 66 10 10 1.0 168 69 16 .4 1.8 260 299 62 206 70 482 8.3 280 Minimum 60 8.9 .11 6.0 1.0 8.8 .0 16 4.8 8.0 .0 .0 82 62 0 19 6 57 6.4 5, NEWNANS LAKE NEAR GAINESVILLE-Semi-annual Average 71 1.7 .88 4.0 1. .4 .6 11 2.3 7.9 2 1.0 .0 29 64 87 1 7 61 5.9 80 Maximum 88 8.0 .65 5.6 1.7 9.0 1.0 21 8.2 14 .8 4.4 .1 45 76 41 21 9 86 0.6 110 Minimum 55 .1 .14 8.2 .9 8.8 .0 4 1.2 2.5 .2 .0 .0 21 53 81 12 4 49 5.8 50 CAMPS CANAL NEAR ROCHELLE-Semi-annual Average 69 1.9 .88 8.8 1.0 4.6 .2 8 2.5 8.2 .2 1.6 .2 28 52 19 18 7 55 5.7 85 Maximum 84 2.6 .66 4.4 1.1 6.2 .5 10 4.8 10 .2 4. .5 82 64 88 15 9 68 5.9 110 Minimum 55 1.1 .08 8.2 .7 8.9 .0 4 .8 5.8 .1 .0 .0 24 29 5 12 4 48 5.5 60 LOCHLOOSA CREEK AT GROVE PARK-Semi-annual Average 67 6.4 .28 8.6 1.0 5.1 .4 9 1.6 8.5 .2 .2 .4 82 74 42 17 9 68 5.7 177 Maximum 88 11 .40 4.4 2.7 7.1 .9 14 2.4 12 ..8 .7 47 02 45 22 12 78 6.1 220 Minimum 58 2.2 .07 2.0 1.0 8.8 .0 4 .4 5.0 .2 .1 .0 17 60 89 9 6 40 6.4 160 2Daily October 1969 to September 1960, 6-8 week intervals July 1957 to September 1969.

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TABLE 5, (CONTINUED). Hardne s .as CaCO3 S040 l 6. .5 O 1 6 84 to LAKE LOCHLOOSA NEAR LOCHLOOSA-Semfi-annual Average 70 1.7 .20 12 2.6 6.6 0.5 37 7.0 12 0.2 0.6 0.0 63 77 21 40 9 112 6.7 46 Maximum 85 5.7 .56 15 3.8 7.8 1.0 50 12 16 .3 1.0 1.1 84 91 80 51 12 142 6.8 75 Minimum 59 .0 .06 8.0 1.7 5.8 .1 20 3.2 10 .2 .0 .0 44 49 6 29 5 88 6.6 15 ORANGE LAKE AT HEAGEY'S FISHING CAMP-Semi-annual Average 60 1.4 .18 6.0 1.8 5.4 .0 20 2.0 8.8 .2 .4 37 57 20 28 6 71 6.4 52 Maximum 88 2.0 .16 7.6 1.7 6.8 .9 20 2.4 10 .3 .8 89 67 28 24 7 79 6.5 65 Minimum 58 .7 .10 6.0 1.1 4.8 .1 20 1.2 7.5 .2 .2 84 46 8 22 6 65 6.4 45 ORANGE LAKE NEAR BOARDMAN-Semi-annual Average 78 8.8 .20 6.3 1.6 4.6 .4 20 1.0 8.4 .2 .8 87 58 28 22 6 71 6.4 62 Maximum 88 4.8 .28 6.8 1.0 4.7 .8 21 8.0 10 .8 1.3 42 66 80 25 8 88 6.5 80 Minimum 69 2.8 .16 6.0 1.2 4.6 .1 18 .8 7.0 .1 .2 88 49 16 20 4 61 6.8 50 CRYSTAL LAKE NEAR KEYSTONE HEIGHTS-Semi-annual Average 72 1.7 .04 2. .5 8.1 .5 8 2.4 4.5 .0 .1 .0 19 21 8 2 88 6.6 6 Maximum 88 4.4 .05 4.0 .7 8.8 1.0 18 8.5 5.5 .1 .2 .0 26 81 7 11 8 41 7.7 15 Minimum 61 .0 .02 1.4 .2 2.7 .0 8 1.6 3.5 .0 .0 .0 15 16 1 5 0 27 5.7 2

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SAND HILL LAKE NEAR KEYSTONE HEIGHTS-Semi-annual Average 74 2.5 0.9 0.9 0.5 8.2 0.1 8 * 2.0 56.0 0.1 0.1 0.0 17 22 6 4 2 28 5.4 10 Maximum 87 4.0 .23 1.4 -.7 8.6 .4 4 8.5 5.8 .1 .2 .0 20 26 11 6 4 87 5.7 88 Minimum 55 1.3 .01 .4 .4 2.8 .0 1 .8 4.2 .0 .0 .0 14 16 2 4 0 24 4.8 2 MAGNOLIA LAKE NEAR KEYSTONE HEIGHTS-Semi-annual Average 67 1.3 .05 1.0 .8 2.8 .1 8 2.4 4.6 .0 .1 .0 14 20 6 4 1 26 5.6 11 Maximum 88 1.9 .07 1.2 .6 2.9 .2 4 2.8 6.0 .1 .6 .0 15 28 14 4 2 28 6.1 20 Minimum 56 .8 .02 .8 .1 2.6 .0 2 1.8 4.0 .0 .0 .0 13 15 2 4 0 24 5.1 8 LAKE BROOKLYN NEAR KEYSTONE HEIGHTS-Semi-annual Average 75 .0 .08 1.8 .7 3.6 .2 8 4.1 5.8 .0 .1 .0 18 23 5 6 4 85 5.5 4 Maximum 88 1.4 .05 1.6 1.2 4.4 .4 4 5.5 7.0 .1 .2 .1 21 84 18 9 8 41 5.7 10 Minimum 60 .2 .02 1.0 .2 2.6 .0 1 2.5 4.8 .0 .0 .0 14 19 1 4 2 26 5.1 2 LAKE GENEVA NEAR KEYSTONE HEIGHTS-Semi-annual Average 70 .9 .01 1.3 1.1 6.1 .6 2 5.8 9.8 .1 .1 26 81 6 8 6 54 5.4 4 Maximum 88 2.6 .02 2.0 1.83 6.4r 1.0 4 6.8 10 .1 .2 28 84 8 8 7 s6 5.6 10 Minimum 60 .0 .00 .8 .7 5.6 .0 1 8.0 8.5 .0 .0 26 26 2 8 4 62 5.1 0 JOHNSON LAKE AT GOLD HEAD BRANCH STATE PARK NEAR KEYSTONE HEIGHTS-Semi-annual Average 71 8.1 0.05 0.7 0.8 2.8 .1 8 2.5 3.7 .0 .1 .1 14 17 4 3 1 22 6.5 15 Maximum 84 8.8 .05 1.2 .5 2.4 .4 4 8.2 4.0 .1 .1 .2 20 20 6 4 8 24 5.09 80 Minimum 59 2.4 .04 ..4 .2 2.0 .0 2 .0 8.2 .0 .0 .0 11, 14 1 2 0 20 5.2 5 PEBBLE LAKE NEAR KEYSTONE HEIGHTS-Semi-annual Average 72 2.1 .08 .8 .8 2.5 .2 3 1.6 8.7 .1 .1 .2 18 14 2 4 1 22 5.6 4 Maximum 85 4.7 .05 1.0 .6 8.4 .5 4 2.8 4.0 .1 .4 .4 18 21 8 4 2 24 5.9 10 Minimum 61 1.0 .01 .8 .1 2.0 .0 2 .8 3.5 .0 .0 .0 10 10 0 8 0 19 5.2 0

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TABLiS 5, (CONTINUED). Hardnee 0 ,S3 S a 0 as 0a00, 0 HALL LAKE NEAR KEYSTONE HEIGHTS-Semi-annual Average 71 0.0 .02 2.0 1,8 7.4 6.4 1 18 18 0.1 0.1 0.0 890 45 12 18 12 80 4.0 4 Maximum 81 1.1 .04 2.4 2,1 8.4 .0 2 10 14 .1 .2 .1 47 02 25 14 .18 89 56.8 10 Minimum 50 .0 .01 1.0 1.6 0.1 .0 0 11 12 .1 .0 .0 86 87 8 11 10 74 4.7 0 SMITH LAKE NEAR KEYSTONE IIEIGHTS-Semi-annual Average 72 .8 .08 2.9 2.1 11 .0 2 15 18 .1 .1 .0 52 04 12 10 15 108 5.2 6 Maximum 88 1.4 .04 8.6. 2.4 14 1.4 8 20 22 .2 .4 .1 68 74 14 19 18 128 5.6 10 Minimum 569 .0 .01 2.0 1.9 9.1 .0 1 8.8 14 .0 .0 .0 47 01 11 14 12 94 4.9, 0 LAKE GRANDIN NEAR INTERLACHEN-Semi-annual Average 78 0.7 .08 2.0 1.2 5.9 0.1 5 5,5 0,7 .0 .1 .0 28 85 7 10 5 54 5,6 7 Maximum 80 1. .12 2.2 1. .2 .8 4 10 .1 .2 .1 28 89 12 10 6 7 .7 10 Minimum 60 .0 .05 1.8 1.0 5.5 .0 4 4.0 9.65 .0 .1 .0 27 82 4 10 8 51 6.6 5 KINGSLEY LAKE NEAR CAMP BLANDING-Semi-annual Average 78 1.1 .02 2.7 .9 5.8 .4 7 4.9 8.7 .1 28 80 8 11 4 51 6.8 6 Maximum 82 1.0 .08 8.4 1.0 0.2 .6 8 56. 10 .1 .1 82 87 7 12 56 7 0.8 8 Minimum 56 .8 .01 2.2 .7 4.7 .2 4 2.0 8.0 .0 .0 20 22 2 10 8 86 5.9 5 , .0 0 1 8

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NORTH FORK BLACK CREEK NEAR HIGHLANDS Average 68 6.8 0.85 12 1.9 16 0.5 5 54 7.6 0.2 0.4 102 180 28 88 88 178 5.8 94 Maximum 80 88 .54 82 .1 72 1.9 6 85 12 .4 8.6 816 886 62 102 9S 492 6.9 280 Minimum 82 .8 .20 2.4 .0 4.2 .0 0 4.0 8.8 0 .0 26 54 0 0 40 4.4 5 YELLOW WATER BRANCH NEAR MAXVILLE--Semi-annual Ave'age 68 9.7 .82 0.4 2.1 8.9 1.9 84 8.9 14 .1 .4 .8 67 88 18 82 4 108 6.5 58 Maximum 76 15 .58 15 85 12 4.9 56 8.0 18 .2 1.7 1.1 96 114 29 50 6 154 7.1 110 Minimum 56 2.8 .21 1.6 .2 2.6 .0 8 1.2 4.5 .1 .0 .0 14 85 2 5 2 26 6.5 10 NORTH FORK BLACK CREEK NEAR MIDDLEBURG-6-8 week intervals Average 62 7.1 87 8.6 1.8 9.8 0.5 18 28 8.4 ,2 .5 66 100 84 29 18 108 6.1 175 Maximum 75 11 .68 28 8.9 20 1.9 25 96 12 .4 1.7 170 184 66 86 68 270 6.8 1,000 Minimum 48 1.1 .16 .8 .0 8.2 .0 1 .8 8.5 .1 .1 20 59 9 8 6 88 4.7 6 ATES CREEK NEAR PENNEY FARMS-Semi-annual Average 64 5.9 .82 1.9 .6 4.4 .1 8 1.7 7.6 .2 .2 .6 24 50 25 7 5 40 5.2 158 Maximum 7 7.9 .40 24 1.1 5.9 .4 5 8.2 10 .8 .1.0 81 74 46 9 8 56 5.6 220 Minimum 52 2.9 .24 .8 .1 2.7 .0 1 .5 4.5 .1 .1 .4 14 80 8 4 2 27 4.7, .80 GREEN'S CREEK NEAR PENNEY FARMS-Semi-annual Average 68 7.9 .28 4.9 .7 5.6 .1 18 1.0 10 .1 .1 .1 87 60 26 15 4 60 6.1 82 Maximum 74 11 .27 9.2 1.6 7.0 .4 27 1.8 14 .2 .4 .2 48 78 26 26 6 80 6.8 110 Minimum 49 2.6 .17 1.6 .0 8.0 .0 0 .4 4.2 .1 .0 .0 12 86 24 4 2 81 4.7 60 BULL CREEK NEAR MIDDLEBURG--Semi-annual Average 61 6.4 .28 4.8 1.6 8.8 .4 15 8.8 6.8 .2 .0 .8 85 57 26 17 4 62 6.8 126 Maximum 74 7.8 .26 7.6 2.2 '4.6 1.0 81 5.0 9.0 .2 .1 .5 49 64 85 28 7 70 7.0 200 Minimum 61 8.1 .21 1.6 .6 2.0 .0 2 1.6 4.0 .2 .0 .2 18 68 21 6 2 80 5.1 70 aSeri-annual July, 1967 to September 1958, Daily October 1958 to September 1956, 6.8 week intervals October 1959 to September 1960.

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TABLE 5, (CONTINUED), Hardnei C. an CaCO 0 SOUTH FORK BLACK CREEK NEAR PENNEY FARMS4 Average 60 6.4 0.80 8.8 0.0 4.8 0.8 11 2.7 7.4 0.2 0.2 81 58 27 18 4 51 6.1 186 Maximum 82 18 .64 84 8.2 7.2 .7 90 22 12 .4 8.4 127 156 57 98 80 228 7.6 860 Minimum 50 1.4 .17 1.0 .1 1.8 .0 4 .0 8.0 .0 .0 12 28 8 8 0 18 5.8 10 DEEP CREEK NEAR RODMAN-Semi-annual Average 64 10 .17 16 4.9 8.4 .6 64 8.0 6.5 .2 .0 .2 76 91 16 58 6 124 7.2 98 Maximum 74 17 .24 10 6.2 8.8 1.6 87 6.0 6.5 .8 .1 .8 90 104 8 78 10 154 7.6 190 Minimum 57 4.5 .11 6.2 2.1 8.1 .1 20 .8 4.5 .1 .0 .0 82 71 4 24 2 66 6.7 85 SOUTH FORK BLACK CREEK NEAR CAMP BLANDING S. R. 21 8/18/59 66 2.9 .14 5.8 .9 4.4 .0 12 8.6 7.0 .2 .0 81 46 15 18 8 62 6.5 50 CLARKS CREEK NEAR GREEN COVE SPRINGS 9/80/58 11 11 .7 6.2 35 2.2 9.0 .2 .0 .2 58 -0 2 87 7.1 80 4Daily October 1958 to September 1059, 6-8 week intervals July 1957 to September 1958 and October 1959 to September 1960.

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PETERS CREEK NEAR PENNEY FARMS 9/80/58 8.8 6.0 .6 4.8 .20 0. 7.5 .2 .0 .8 89 18 1 8 6.8 40 BOGGY BRANCH NEAR CAMP BLANDING 12/17/57 6.6 .18 2.8 1.6 4.2 .0 7 8.5 9.0 .1 .1 .8 81 64 88 18 8 49 6.1 120 8/18/58 62 5.1 .08 2.6 1.0 5.4 .5 8 2.5 9.0 .2 .8 28 71 48 10 8 58 5.0 180 NORTH FORK BLACK CREEK UPSTREAM FROM CONFLUENCE OF BOGGY BRANCH 12/17/67 10 .10 18 4.7 20 .4 0 118 8.5 .2 .7 .0 172 190 18 52 52 288 4.4 80 8/18/58 8.0 .24 14 2.4 86 .3 2 105 8.2 .1 .7 .... 176 108 22 45 44 808 56.0 20 n:

PAGE 102

88 FLORIDA GEOLOGICAL SURVEY A section of this report describes the significance of water quality in relation to water use (p. 152). From the data which have been summarized in table 4, it can be seen that the concentration of substances dissolved in the water in streams of the area, during the period, seldom exceeded 200 ppm, except for the Santa Fe River at High Springs and the North Fork Black Creek near Highland. During the period of study the maximum concentration and the variability of the substances dissolved in the water of the streams at these two stations exceeded all other stations throughout the area. Manmade factors added to the natural factors in the North Fork Black Creek basin are responsible for the higher maximum concentrations of substances dissolved in the stream, whereas in the Santa Fe River basin natural factors are almost entirely responsible. Other major stream basins in the area for the most part show little or no effects of manmade factors upon the concentration of substances dissolved in the water. There are other specific differences in water quality of different stream basins to be noted. The differences include not only the total concentration and variability of concentration but also the different kinds of substances dissolved in the streams and their frequency of occurrence. For convenience, a description of water quality in each major river basin follows. SANTA FE RIVER BASIN Santa Fe Lake, Little Santa Fe Lake, and Hampton Lake exhibit little difference in average water quality during the period of this study. Concentration of substances dissolved in the Santa Fe River water at Graham averaged 93 ppm, about twice the concentration of substances dissolved in the three lakes mentioned above. Inflow from these three lakes and from swamps accounts for most of the surface-water inflow to the Santa Fe River upstream from Graham. The average concentration of mineral matter is about the same at Graham as in the lakes; however, the range in mineral content is much greater in the river, 60 ppm as compared to 20 ppm in the lakes. Water entering the Santa Fe River from the swamps must be high in color because color at Graham averaged 275, more. than four times the color in the lakes. The average concentration of iron in the Santa Fe River was 0.38 ppm, which is about 21/2 times

PAGE 103

REPORT OF INVESTIGATIONS NO. 35 89 the concentration in the lakes. Organic matter has a tendency to stabilize iron in solution. Residue on evaporation at 180°C, hardness, and organic matter in relation to specific conductance have been plotted in figure 48. The substances most likely to affect the usefulness of water are those shown in figure 48 and iron. A large part of the time the dissolved substances are mostly organic matter (fig. 48). The mineral matter (difference between organic matter and residue on evaporation at 180°C) is primarily calcium and magnesium bicarbonates. Specific conductance and discharge have been plotted in figure 49. In general, specific conductance is less at high flow than at low flow; however, the exact relationship is not apparent, as demonstrated by the scatter of points in figure 49. The cumulative frequency of specific conductance, residue on evaporation at 180°C, sum of determined constituents, and color are shown in figures 50, 51, 52, and 53. These curves are based on intermittent sampling between October 1958 and September 1959. A cumulative frequency curve shows the percentage of samples having a characteristic equal to or less than the indicated amount. The average concentration of each mineral in the Santa Fe River except chloride shows a small increase between Worthington and Graham. Chloride concentration decreased slightly. The 140 120 .Residue on evaporation at 1800 C Z 100 * Hardness (calcium plus 0 magnesium as calcium _J .carbonate) S80 / Organic matter w " , / / a-60 00 40 e 20 ~ 0--e ---0 20 40 60 80 100 120 140 160 SPECIFIC CONDUCTANCE IN MICROMHOS AT 250 C Figure 48. Residue on evaporation at 1800C, hardness, and organic matter in relation to specific conductance, Santa Fe River at Graham, Florida, July 1957 to September 1960.

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90 FLORIDA GEOLOGICAL SURVEY 150 f__ ISO 100 ' 80 60 g -T ------0-_s o 60 I4O ----'---r---.-----40 z __ _ _ _ -----__-----_____z 30 020 Uj 10 S1 20 30 40 60 80 100 200 300 400 600 800 FLOW,IN CUBIC FEET PER SECOND Figure 49. Specific conductance in relation to flow, Santa Fe River at Graham, Florida, July 1957 to September 1960. average concentration of substances dissolved in the water is about the same at Worthington and at Graham, but at Worthington the water contains more mineral matter and less organic matter than at Graham. Inflow from tributaries between Graham and Worthington is small and has a minor effect upon water quality. New River is one of the largest tributaries to the Santa Fe River upstream from Worthington. It has more effect on the water quality than any other tributary. Water samples were collected daily from New River near Lake Butler from July 1957 to September 1958 and intermittently from September 1958 to July 1960. The concentrations of several constituents in these samples were plotted against conductance (fig. 54). The variation of conductance with flow was plotted in figure 55 and cumulative frequency curves for several constituents were plotted in figure 56. Samples were collected daily from the Santa Fe River at Worthington from July 1957 to September 1960. Several constituents have been plotted against specific conductance in figure 57. The relation between conductance and flow is shown in figure 58. Cumulative frequency curves are shown in figure 59. Olustee Creek, which enters the Santa Fe River below Worthington, has an average flow of about one-half that of New River.

PAGE 105

REPORT OF INVESTIGATIONS NO. 35 91 & Olustee Creek near Providence, 1958-59 water year * Santa Fe River at Graham, 1958-59 water year * North Fork Black Creek near Middleburg,1958-59 water year 135 125 0 < 115-_S105 0 0 95 z 8 15 -------------75 ---J 5 &/4----(-&z 45 1-75-----f-----35 0 2 5 10 30 50 70 90 99 PERCENT OF SAMPLES Figure 50. Cumulative frequency curve of specific conductance of selected streams (periodic samples). The average concentration of substances dissolved in Olustee Creek water near Providence is about 10 to 15 percent less than that in the Santa Fe River water at Worthington. The concentration of dissolved matter in Olustee Creek water averaged 84 ppm, of which 29 ppm was mineral matter and 55 ppm was organic matter. The chemical 'character of the water is shown graphically in figures 50-53 and 60-61.

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92 FLORIDA GEOLOGICAL SURVEY A Oiustee Creek near Providence, 1958-59 water year * Santa Fe River at Graham, 1958-59 water year a North Fork Black Creek near Middleburg, 1958-59 water year o 140 120 S80 i o 40 =20 1 2 5 10 30 50 70 90 99 PERCENT OF SAMPLES Figure 51. Cumulative frequency curve of residue of selected streams (periodic samples). The average concentration of substances dissolved in the Santa Fe River water at High Springs was 193 ppm. At this station the water is more mineralized than at any place upstream. Calcium plus magnesium bicarbonate and, to a lesser extent, calcium sulfate accounts for most of the increase. Organic matter is a little less concentrated in the river at this station. The chemical character of the water is shown graphically in figures 62 to 64. Natural factors are sufficiently different within the Santa Fe River basin to cause most of the water-quality variations observed. Streams tend to have increasing concentrations of substances dissolved in the water at successive downstream locations. The range in concentration also increases. Color would probably be the most objectionable characteristic of water in the Santa Fe River basin for most water uses. The second most objectionable characteristic would probably be iron, and the third most objectionable characteristic would probably be hardness.

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REPORT OF INVESTIGATIONS No. 35 93 A Olustee Creek near Providence,1958-59 water year * Santa Fe River at Graham,1958-59 water year * North Fork Black Creek near Middleburg, 1958-59 water year 80 ,) 70 z Iol,,t 70 =///---z 60 oo -_______50__ SZa/ S2 5 0 30 50 70 90 99 12 5 10 30 50__ 70 90 99 PERCENT OF SAMPLES Figure 52. Cumulative frequency curve of selected streams (periodic samples). BLACK CREEK BASIN NORTH FORK BLACK CREEK The concentration of dissolved substances in the water of the head of North Fork Black Creek averaged about 30 ppm and fluctuated through a range of about 15 ppm. There was little organic matter present. The concentration of mineral matter (dissolved substances less organic matter) averaged 28 ppm and ranged from 20 to 32 ppm. The water contained negligible concentrations of iron and was very soft. From Kingsley Lake to Boggy Branch, the water flows through swampy areas and color increased to 100 units or more, but there was little change in the concentration of mineral matter. From Boggy Branch to near Highland the average concentration of substances dissolved in the water increased from about 30 to

PAGE 108

94 FLORIDA GEOLOGICAL SURVEY A Olustee Creek near Providence, 1958-59 water year * Santa Fe River at Graham, 1958-59 water year * North Fork Black Creek near Middleburg, 1958-59 water year 450 -400 z 50 1350--_T co -----------__ _----..a300 ------0 o / o 100 250 S200 50 70 90 99 samples).. 130 ppm. The concentration ranged from 54 to 336 ppm near S 150 ----_--_ -8 !00 ppm near Highland to about 100 ppm near Middleburg. The 50 figures 50 to 53 and 65 to 69. 1 2 5 10 30 50 70 90 99 PERCENT OF SAMPLES Figure 53. Cumulative frequency curve of color of selected streams (periodic samples). 130 ppm. The concentration ranged from 54 to 336 ppm near Highland. The average concentration decreased from about 130 ppm near Highland to about 100 ppm near Middleburg. The chemical character of waters of North Fork Black Creek basin is shown in figures 50 to 53 and 65 to 69. Both natural and manmade factors significantly affected the water quality of North Fork Black Creek water. Under conditions similar to those during this study period color, iron, hardness, and pH would often be objectionable for many water uses.

PAGE 109

REPORT OF INVESTIGATIONS No. 35 95 200 180 160 140 z a. 80. " ./ ,X o ... 60 40 260 1 ---S / "/ s 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 SPECIFIC CONDUCTANCE IN MICROMHOS AT 25°C * Residue on evaporation at 180 C e Hardness (calcium plus magnesium as calcium carbonate) / Organic matter Figure 54. Residue on evaporation at 180°C, hardness, and organic matter in relation to specific conductance, New River near Lake Butler, Florida, July 1957 to September 1960. SOUTH FORK BLACK CREEK The average concentration of substances dissolved in the waters of Ates Creek, Greens Creek, and Bull Creek, was 50 ppm, 60 ppm, and 57 ppm, respectively (table 5). The average condition for Ates Creek was characterized by mineral matter and organic matter each equaling about 50 percent of the substances dissolved in the water. The average water-quality conditions for Green Creek and Bull Creek were characterized by about 10 ppm more mineral matter than organic matter. The chemical character of South Fork Black Creek near Penney Farms, downstream from the junction of Ates and Greens creeks but upstream from the junction of Bull Creek, was about the same as the average of the tributaries above Penney Farms; concentrations of mineral matter and organic matter were about equal

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' I " ' ': 'i" " " S ..-* . S * " 6 I " * -' .." * 31 00 r * * .* '* * .* * S .* 8 oc ." ' * " -.-"" '-*. * S* z: : *.-j* : 6 * ..** * | :-loo" ---.-:.0»-f--.. -, ,' * r * : *. .. .... .* * .* 0o * s __•__ _ _ F.0 -___o '. o ' .." . S-,. -----m 8 10 20 30 40 60 80 100 200 300 400 600 800 1,700 FLOW, IN CUBIC FEET PER SECOND Figure 55. Specific conductance in relation to flow, New River near Lake Butler, Florida, July 1957 to September 1960.

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REPORT OF INVESTIGATIONS NO. 35 97 170 150 "4i z 130 0 -_,__ 2 110 4Z-a 170 50 -£ A Residue on evaporation at 180°C IU Sum of determined constituents 30 ---------1--I-I -I-350 I 2 5 10 30 50 70 90 99 999 PERCENT OF TIME 350C--i----i-11 -1 --i-1--i-i---------_--,---0 Color __ S3 * Specific conductance z _~-----__---__-_ -_---__---_ S2 90 ----..--__ -_ -_ -_ 0 o 0 o o -o--0C,,--------, -0 I7 230sI------C I4C 9V -------------------_ ----J ^-Il------------__--_ BC 2----y--_ ---_ 8O C 0 170S14050 ___ 1 2 5 10 30 50 70 90 99 99.9 PERCENT OF TIME Figure 56. Cumulative frequency curves of selected characteristics of water from New River near Lake Butler, Florida, October 1957 to September 1958.

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98 FLORIDA GEOLOGICAL SURVEY 140 Z -,o----: -------. 120 -. . I 2 100 80 60 eS60 CL 40 -20 0 20 40 60 80 100 120 140 160 180 200 220 SPECIFIC CONDUCTANCE IN MICROMHOS AT 250 C 100 z o 80so / .Residue on evaporation 2 GO ___ _ at 180°C S' ' // e Hardness(calcium plus a. / ' / / , magnesium as calcium o401 / carbonate) S20_ / /// / / /Organic matter < 20 -' O 20 40 60 80 100 120 140 160 SPECIFIC CONDUCTANCE IN MICROMHOS AT 250C Figure 57. Residue on evaporation at 1800C, hardness, and organic matter in relation to specific conductance, Santa Fe River at Worthington, Florida, July 1957 to September 1960. and totaled 58 ppm. The fluctuations in chemical characteristics observed near Penney Farms were more than twice those observed for any tributary waters. The chemical character of the water is shown graphically in figures 70 to 72. Natural factors are the principal cause of water-quality variability in the South Fork Black Creek basin; however, there are, occasionally, minor effects from manmade factors.

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REPORT OF INVESTIGATIONS No. 35 99 300 I200I II I 1 ii' 20 20 30 40 60 80 100 200 300 400 600 BO800 00 2-00 4200t000 FLOW.IN CUBIC FEET PER SECOND Figure 58. Specific conductance in relation to flow, Santa Fe River at The most objectionable water-quality characteristics for most water uses probably are color and iron. The average hardness, as calcium carbonate, was low, 13 ppm. ETONIA CREEK BASIN Water from lakes and streams in Etonia Creek basin in Clay County is good. The concentration of substances dissolved in Lake Geneva averaged about 31 ppm, in Hall Lake about 45 ppm, and in Smith Lake about 64 ppm (table 5). Many of the lakes in the basin contained less than 30 ppm. The range in concentrations was small, 25 ppm in Hall Lake and 15 ppm or less in most other lakes. Organic matter was almost absent from the lakes and streams in the basin, and concentrations of iron were hardly significant in most samples. Natural factors determine water quality in Etonia Creek basin. ORANGE CREEK BASIN The average concentration of substances dissolved in Lochloosa Creek at Grove Park was about 74 ppm. The average concentration of organic matter was about 10 ppm more than the average concentration of mineral matter. The average concentration of substances dissolved in Lochloosa Lake was about the sameo as that in Lochloosa Creek at Grove Park, but the range in concentrations was a little greater in Lake Lochloosa. Waters from Newnans Lake, Camps Canal, and Orange Lake are very similar The average concentration of substances dissolved are very similar. The average concentration of substances dissolved

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100 FLORIDA GEOLOGICAL SURVEY 120 -too 90--1 7z---30 70 SResidue on evaporation 1800C 0 Sum of determined constituents--------50 -I -I ---/----3 2 5 10 30 50 70 90 99 999 PERCENT OF TIME 360-------OColor 320 --_---^-4---J-L_, ---C---20 Specific conductance 820 S----------40 1 2 5 10 30 50 70 90 99 999 PERCENT OF TIME Figure 59. Cumulative frequency curves of selected characteristics of water from Santa Fe River at Worthington, Florida, October 1957 to September 1958. s I ----, -=,, i ,gzz.^ mr I ^ -_ _ --^ _ _ -_ -_ "i --^-2.*6-} ^ --^ .i -^ --,.-^ -s 1958.

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REPORT OF INVESTIGATIONS No. 35 101 300 -280 260 -240 -220 -200 20 .. 40 ---120 ^ 60 ----------------------1---------' -------I 140 20j / 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 SPECIFIC CONDUCTANCE IN MICROMHOS AT 25"C .Residue on evoporation at 180 C .Hardness (calcium plus magnesium as calcium carbonate ,Organic m ltter Figure 60. Residue on evaporation at 1800C, hardness, and organic matter in relation to specific conductance, Olustee Creek near Providence, Florida, July 1957 to September 1960. 300 1 loo ,0 ----_-__ -----_ _ _I ___---100 4 6 7 8 9 -0 30 40 60 I00 200 300 500 700 ,00 2000 4-000 FLOW,N CUBIC FEET PER SECOND Figure 61. Specific conductance in relation to flow, Olustee Creek near Providence, Florida, July 1957 to September 1960. U0 I0 W 20-----_10 3 4 5 6 7 8 9 20 30 40 60 80 100 200 300 500 700 1u00 2POO 4,000 FLOWWI CUIBIC FEET PER SECOND Figure 61. Specific conductance in relation to flow, Olustee Creek near Providence, Florida, July 1957 to September 1960.

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102 FLORIDA GEOLOGICAL SURVEY 120 [ --) --[ -| --| -1200 0 _ 80 .-57 S" • * Residue on evaporation at 180 C w 60 -e Hardness (calcium plus magnesium a .as calcium carbonate) ' S40/ Organic matter / / / 20 ---9l ^ ~ --0 20 40 60 80 100 SPECIFIC CONDUCTANCE IN MICROMHOS AT 250 C Figure 62. Residue on evaporation at 1800C, hardness, and organic matter in relation to specific conductance, Santa Fe River at High Springs, Florida, July 1957 to September 1960. in each was 64 ppm or less. Coloring organic matter was more variable in Newnans Lake and Camps Canal. Orange Lake becomes more mineralized during extreme droughts. Concentration of dissolved matter may be as much as 150 ppm in the area of the large sinkhole at the southwestern edge of the lake. Natural factors determine water quality in the Orange Creek basin. Except for color and iron, the water would be suitable for most uses. GROUND WATER Ground water is the subsurface water in the zone of saturation -the zone in which all pore spaces are completely filled with water. The zone of saturation is the reservoir from which all water from springs and wells is derived. The term "aquifer" is defined as a layer of material or a group of layers, in the zone of saturation, that is permeable enough to readily yield usable quantities of water to wells or springs. Ground water may occur under either water-table or artesian conditions. Where it is unconfined, its surface is free to rise and fall and it is under water-table conditions. The water table is the upper surface of the zone of saturation, except where that surface is formed by a relatively impermeably material such as clay. Where

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REPORT OF INVESTIGATIONS No. 35 103 o 400 5 300 g ···,.. --.. .o ** . o .V °° ....o 0. 0 * O 200 .1. I, .) * .. z .00 0 ig) ..S *to oS S1o--.---0 0o impermeable overlying material, it is under artesian conditions. The term "artesian" is applied to water that is under sufficient pressure to rise above the base of the confining material. Thus, by teo extent to which water levels may be lowered without 0 40 60 80 100 200 300 400 600 FLOW,IN CUBIC FEET PER SECOND Figure 63. Specific conductance in relation to flow, Santa Fe River at High Springs, Florida, July 1957 to September 1960. ground water is confined in an aquifer under pressure by a relatively impermeable overlying material, it is under artesian conditions. The term "artesian" is applied to water that is under sufficient pressure to rise above the base of the confining material. Thus, artesian water does not necessarily rise above the land surface. The piezometric surface of an artesian aquifer is the surface to which water would rise in tightly cased wells that are open to the aquifer. LIMITATIONS OF YIELD The amount of water that can be pumped from a well may be Slimited by any of several factors. In general, the yield is determined by the extentto which water levels may be lowered without

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104 FLORIDA GEOLOGICAL SURVEY 275 SA Residue on evaporation at 180C __ SSum of determined constituents 225 200. 17 5 0 3 50 70 90 99 999 PERCENT OF TIME 400 z Color ----360 -5 BO5. -----------SSpecific conductance S320 S50 ------S240 40 I 5 K 30 50 70 90 9 99.9 PERCENT OF TIME I --30 50 70 90. 99 99.9 Figure 64. Cumulative frequency curves of selected characteristics of water from Santa Fe River near High Springs, Florida, October 1958 to September 1959.

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REPORT OF INVESTIGATIONS NO. 35 105 Residue on evaporation at 180°C * Hardness (calcium plus magnesium as calcium carbonate) / Organic matter 240 I --220 200 180 180----------------------------------------------------------------------160 z 0 r 140 a. 60 V . 80I ----40 20 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 SPECIFIC CONDUCTANCE IN MICROMHOS AT 250C Figure 65. Residue on evaporation at 1800C, hardness, and organic matter in relation to specific conductance, North Fork Black Creek near Highland, Florida, July 1957 to September 1960. adversely affecting the quality of the water, or making the cost of obtaining it prohibitive, or causing the well to fail. Lowering of the water level inevitably accompanies pumping and is necessary to cause water to flow into the well from surrounding formations. The amount of lowering (or the drawdown) is approximately proportional to the rate of pumping. The relationship between the rate of pumping and the drawdown in a well is often used to estimate the drawdown in or the yield of a well. This relationship is called the specific capacity of a well and is controlled by several factors; principally the ease with which the aquifer transmits water, the capacity of the aquifer to store water, the well construction, the conditions under which water is recharged to the aquifer and discharged from the aquifer, and the length of pumping time. The specific capacity is the pumping rate divided by the drawdown. For example, if a well is pumped at the rate of 200 gpm (gallons per minute) and if the water level is lowered 20 feet, its

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106 FLORIDA GEOLOGICAL SURVEY 200 leo-----------------------------180 160 140 W too S80/ 60 40 4 10---------A---; ------20 --0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 SPECIFIC CONDUCTANCE IN MICROMHOS AT 25*C SResidue on evaporation at 180*C * Hardness (calcium plus magnesium as calcium carbonate) 60 ------, ---/ -----/ Organic matter 40 --------/ --------Figure 66. Residue on evaporation at 18000, hardness, and organic matter in relation to specific conductance, North Fork Black Creek near Middleburg, Florida, July 1957 to September 1960. specific capacity is 10 gpm per foot of drawdown. Accordingly, if the specific capacity of a well is 10 gpm per foot of drawdown, the implication is, within certain limits, the yield of the well will be increased 10 gpm for each additional foot of drawdown. The drawdown may, however, be limited to the amount which if exceeded would allow saline or highly mineralized water to move into the well. The possibility of the drawdown being limited by the intrusion of saline or highly mineralized water is greater in very deep wells that have penetrated relatively impermeable zones in the lower part of the aquifer than in shallower wells. The ultimate drawdown in a well, other things being equal, depends on how the drawdowns affect the recharge to the aquifer and the discharge from the aquifer. Under natural conditions before withdrawals begin, the recharge to an aquifer is balanced by the discharge from the aquifer, except for temporary differences due to changes in the amount of water stored in the aquifer. After pumping from the well begins, the natural balance is upset. For a

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REPORT OF INVESTIGATIONS No. 35 107 S400C--__ -,0 , ZC300-----,-_M .. _ _ _ " ": I __ 300 7200 0 * L100 W 4o 10 20 30 40 60 80 100 200 300 400 600 800 1,00000 FLOW,IN CUBIC FEET PER SECOND SFigure 68. Specific conductance in relation to flow, North Fork Black Creek near iddleburg, Florida, July 1957 to September 1960. 40 tO 20 30 40 60 80 100 200 300 400 600 800 10 5 Fiue6.Seii.cnutnei0elto ofoNrhFr lc re

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108 FLORIDA GEOLOGICAL SURVEY 320 2A8 Residue on evaporation at 180C * Sum of determined constituents 240. o20o t 160 S120 80 ___ _____ 40 I 2 5 10 30 50 70 90 99 99.9 PERCENT OF TIME 540III I SI Color 40' -Specific conductance 0 --------------5 240 --S420 0 0 ---------S0 I i" -------_180 0L ___--~I20 -^ ----____ I 2 5 10 30 50 70 90 99 99.9 PERCENT OF TIME Figure 69. Cumulative frequency curves of selected characteristics of water from North Fork Black Creek near Highland, Florida, October 1958 to September 1959.

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REPORT OF INVESTIGATIONS No. 35 109 160IS--140 120 ---------------120 j 100 d IO * Residue on evaporation at 18O°C --------e Hardness (calcium plus magnesium ." ' as calcium carbonate) O ..U * / Organic matter a . 40---------20-Ave. I 0 20 40 60 80 100 120 140 160 180 200 220 240 SPECIFIC CONDUCTANCE IN MICROMHOS AT 25*C 801----------i---|-----------S40 0 so S6C --40 ^-------------------S 0 40 60 100 120 140 160 180 200 220 240 SPECIFIC CONDUCTANCE IN MICROMHOS AT 250C Figure 70. Residue on evaporation at 1800C, hardness, and organic matter in relation to specific conductance, South Fork Black Creek near Penney Farms, Florida, July 1957 to September 1960. time after pumping begins, practically all of the water is pumped from storage in the aquifer immediately surrounding the well. The pumping of water from storage lowers the water level, and thereby creates a cone of depression around the well. As pumping continues, the cone of depression deepens and broadens until ultimately a new balance is established wherein the rate of recharge is once more equal to the rate of natural discharge, plus the rate of withdrawals. The new balance may occur through an increase in the rate of recharge if circumstances are favorable, to a decrease in the rate of natural discharge, or to a combination of these changes. When recharge once again balances discharge, the decline of the water levels due to pumping ceases, and the water levels once again become stable, except for fluctuations due to natural causes such as intermittent rainfall. The ultimate drawdown in a well therefore is less where the conditions are favorable for the cone of depression to induce additional recharge to the aquifer, or where the conditions are

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110 FLORIDA GEOLOGICAL SURVEY Wi near Penney Farms, Florida, July 1957 to September 1960. _ Ground water for the purposes of this report is'divided into that i te u r a rs ad io tt in te Fr n a r. 0 30 0 4 40 0 300 300 400 C0 900 .000 2.000 5.00 SO 000 UPFLOW.IC FQUT IFER SE Figure 71. Specific conductance in relation to fow, South Fork Black Creek near Penney Farms, Florida, July 1957 to September 1960. favorable for the cone of depression to intercept natural discharge from the aquifer, or both. Ground water for the purposes of this report is divided into that in the upper aquifers and into that in the Floridan aquifer. in which the water is generally under artesian conditions are referred to as secondary artesian aquifers. (fig. 73). UPPER AQUIFERS The upper aquifers in this report refer to those aquifers above the Floridan aquifer. Water in the upper aquifers is under both water-table and artesian conditions. The uppermost aquifer above the Floridan in which the water is generally under water-table contioiins is referred to as the water-table aquifer, and those aquifers between the water-table aquifer and the Floridan aquifer in which the water is generally under artesian conditions are referred to as secondary artesian aquifers. (fig. 73). WATER-TABLE AQUIFER The water-table aquifer, which is the uppermost aquifer in the four counties, consists chiefly of sand and clayey sand of Miocene, Pleistocene, and Pleistocene and Recent age that contains water in most places under water-table conditions. In the vicinity of Keystone Heights the aquifer also includes limestones of the Choctawhatchee Formation. The aquifer along Trail Ridge north of Kingsley Lake consists chiefly of sands of the older Pleistocene terrace deposits and has a maximum thickness of about 130 feet. South of Kingsley Lake in the area where Trail Ridge fans out

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REPORT OF INVESTIGATIONS No. 35 111 150 11 11--&130-&Residue on evaporation at 180'C @Sum of determined constituents z110 2 90 S70 10_ 30 ---10 a-0.1 2 5 10 30 50 70 90 99 99.9 PERCENT OF TIME 225 * •olor 200--e -;;_ a *Specific conductance o 0 50 § 175 --,-____ -_ §50-----__ -t__ __7 W -S10025 0 I 75 0 --01 I 2 5 10 30 50 70 90 99 99.9 PERCENT OF TIME Figure 72. Cumulative frequency curves of selected characteristics of water from South Fork Black Creek near Penney Farms, Florida, October 1958 to September 1959.

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112 FLORIDA GEOLOGICAL SURVEY S--EXPLANATION ei« Z ' rArrow indicates direction in which water is moving 250,zI-CF---ID"A N A.OR/ Figure 73. Generalized geologic sectio -Archer-torange Park, Florida showing aquifers and the movement of water. into a series of hills and lakes, the aquifer is generally 70 feet or less in thickness. East of Trail Ridge in Clay County, the aquifer is made up of sands of the Pleistocene and Recent deposits and averages about 50 feet in thickness. West and southwest of Trail Ridge in Alachua, Bradford, and Union counties the aquifer is made up of sands of the older Pleistocene terrace deposits and, in most places, is about 40 feet thick. In Alachua, Bradford, and Union counties in the area that has been mapped as the outcrop area of the Hawthorn Formation (fig. 4), the aquifer consists of a few feet of sands of the older Pleistocene deposits that overlie the 0awthorn Formation and perhaps thin sand or limestone layers near the top of the Hawthorn. The aquifer is absent in southern and western Alachua County (fig.4).onfining CONFIGURATION OF THE WATER TABLE Figure 74 showsGeneralized geologneralized contour lines on the water table.orida The contour lines-that is lines connecting points of equal elevation-show the approximatquifers ande configuration of the water table. The into a series of hills and lakes, the aquifer is generally 70 feet or lesscontours show thickness.at beneath most of Trail Ridge in Clay County, the watquifer table is more up of sthan 200 feet above sea level and thaecent in an area north averages about 50 feet in thickness. Wlest and southwest of Trail Ridge in Alachua, Bradford, and Union counties the aquifer is made up of sands of the older Pleistocene terrace deposits and, in most places, is about 40 feet thick. In Alachua, Bradford, and Union counties in the area that has been mapped as the outcrop area of the Hawthorn Formation (fig. 4), the aquifer consists of a few feet of sands of the older Pleistocene deposits that overlie the Hawthorn Formation and perhaps thin sand or limestone layers near the top of the Hawthorn. The aquifer is absent in southern and western Alachua County (fig.74). CONFIGURATION OF THE WATER TABLE Figure 74 shows generalized contour lines on the water table. The contour lines-that is lines connecting points of equal elevation-show the approximate configuration of the water table. The contours show that beneath most of Trail Ridge the water table is more than 200 feet above sea level and that in an area north

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45' 4' 35' 30' 25' 20' 15' 005' S8200' 55' 50 45 40 35 8130' 7 DUVAi CO U NTY N --7 -5 I I N COUNTY.CL C Y 0E ' 6 1303 -~ 1232 LA 9 I e ond!± 1 -EL SE L NO20 NWE 00105t203 I f.118±20 , ^3 0 B 3 * .t. 3520 .1 0 2 40±20 1"B5 ,R 2 q j 7 ,, ,,e,, AWTH5R N2 LWE 0 No, e bove C 145!3 -25 20 L PE Y 0 2 water table, in fee aboe mn level in June 1960. Dshed line rep4en loa U SGS rs 2o2d Eogl 2 05 E '13KI20 L 0 136!20 14515 0 141!5 @ SCPRVING o120t20 W 132+5r 93t5 ' PNN ig STRKEnd Union counties, Flor , showing generaOized contours on the water t935e in the water-tabe aqui er. /// 355 HAMP6ON 116 S S -3' / HIGH SPRINGS 054-20 5',..., -/5 * 2 N3.J CLAY COUNTYE 0' /0 40 0ohson Z i TNM cot \ l 140// /15 4 \ 9 / i /a5 Ibe in lk i3s l e , e "1 "" XPLAN ATO mea le in J above ma a e ve in oJn 960 / water table in ft a COUNTY mn sqe CO AATY A COUNTY -cantauros itcerv 0 feet. _"1591 Slut, Reed .po5tm l3t moys generalized contours on the water table in the water-table aquifer.

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REPORT OF INVESTIGATIONS No. 35 113 of Gainesville the water table is more than 150 feet above sea level. The contours show that the water table generally slopes to the east and to the west from Trail Ridge north of Sand Hill Lake and to the southeast and to the southwest of Trail Ridge near Sand Hill Lake. The water table conforms in a general way to the topography of the land surface. The water table is higher beneath hills than beneath valleys, but the depth to water below the surface of the land is usually greater beneath hills than beneath valleys. The water table is, on the average, more than 20 feet below the land surface beneath the hills of the lake area near Keystone Heights. The water table is usually less than 10 feet below the surface in Bradford and Union counties and in Clay County east of Trail Ridge. In Alachua County the water table is usually less than 5 feet below the surface. RECHARGE AND DISCHARGE Rainfall replenishes the aquifer by percolating downward to the water table. In addition, a small amount of water recharges the aquifer by seeping upward through intervening confining beds where the "piezometric surfaces of the lower aquifers are above the water table. Water in the aquifer moves from places of recharge to places of discharge. Part of the water that leaves the aquifer is discharged either by evaporation from the surface of the land or by transpiration of the vegetation. A part is withdrawn from wells, and a part seeps downward' through intervening clay layers into the lower aquifers where the water table is higher than the piezometric surfaces of the lower aquifers. Water is also discharged from the aquifer into the lakes and streams as indicated by the map of the water table (fig. 74). Water in the aquifer moves laterally in a direction that is down gradient and at right angle's to contours on the water table. The contours indicate that water from the aquifer is being discharged into the St. Johns River, Black Creek, Santa Fe River, and Hatchet Creek. They also indicate that water is being discharged into Sand Hill Lake and probably into Newnans Lake. FLUCTUATION OF THE WATER TABLE Figure 75 shows hydrographs of four wells that tap the watertable aquifer. During 1958 and 1959 the water table, as shown by the water levels in wells 946-226-1, 000-232-1, and 956-208-1, fluctuated about 4 feet. The water levels fluctuated in response

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114 FLORIDA GEOLOGICAL SURVEY 154 --II I 152 150 (48 Well 946-226-1, 3 miles southeast of Alachua. S146 -Well 000-232-1, 11 miles west of Lake Butler o 1444 C 142 E 140 134 Well 956-208-1, o 132 2.3miles northwest __ a of Starke Q 130 C 128 118 ' Well 946-202-3, > 116 at Keystone Heights% 114 3 112 110 108 106 104 I I i I 1 ! I 1957 1958 1959 1960 Figure 75. Hydrographs of wells 946-226-1, 000-282-1, 956-208-1, and 946-202-8.

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REPORT OF INVESTIGATIONS No. 35 115 to variations in rainfall. During periods of above-average rainfall the water table rose, and during periods of below-average rainfall the water table declined. Unlike the water levels in the other wells the water level in well 946-202-3 steadily rose more than 10 feet in response to the rising level of nearby lakes. WELLS The water-table aquifer, in most places, will yield sufficient water for domestic purposes from shallow dug or sandpoint wells. The amount of water that can be pumped from wells tapping the water-table aquifer is limited by the amount that the water level in the well can be lowered before the well fails. Where the aquifer consists of only a few feet of clayey sand, only meager supplies of water can be withdrawn from the aquifer. Where the aquifer consists of many feet of relatively coarse sand, larger supplies, sufficient for domestic and stock purposes, may be withdrawn. SECONDARY ARTESIAN AQUIFERS The secondary artesian aquifers are sandwiched between the water-table aquifer and the Floridan aquifer. The water contained in the secondary artesian aquifers is generally under artesian conditions. These aquifers are chiefly limestone layers and sand layers in the Hawthorn Formation. Except for the Brooklyn Lake area, limestone layers and shell beds in the Choetawhatchee Formation probably are secondary artesian aquifers. The limestone layers in the Hawthorn Formation ordinarily range in thickness from a few inches to as much as 6 feet. Some of the layers are dense and yield little water; others are porous and readily release water to wells. Although the limestone layers in the Hawthorn Formation are limited in area, they are probably connected with other permeable zones of material such as sand layers. PIEZOMETRIC SURFACES The piezometric surfaces of the secondary artesian aquifers usually lie between the water table and the piezometric surface of the Floridan aquifer. Figure 76 shows the piezometric surface of different aquifers measured when well 000-210-2, which is about 5 miles northwest of Starke, was drilled. The fact that the piezometric surfaces of the deeper secondary artesian aquifers were lower than the piezometric surfaces of the shallower secondary

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116 FLORIDA GEOLOGICAL SURVEY 'I -----------------------------0m 5000M 5C at I lI^IPS [ [ *I 350I A EXPLANATION Water level in well Sand Clay Limestone Figure 76. Geologic sections showing typical water levels in wells tapping : different aquifers. different aquifers.

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REPORT OF INVESTIGATIONS NO. 35 117 artesian aquifers is typical of the area in which the water table is higher than the piezometric surface of the Floridan aquifer. In the areas where the piezometric surface of the Floridan aquifer is higher than the water table the piezometric surfaces of the secondary artesian aquifers are generally higher in the deeper aquifers than in the shallower aquifers. These areas are in and near the areas shown in figures 83 and 87 where wells tapping the Floridan aquifer will flow. Figure 76 shows typical positions of water levels in wells tapping different aquifers in this area. Wells tapping secondary artesian aquifers will flow over most of the area where wells tapping the Floridan aquifer will flow. The area is somewhat smaller for the shallower secondary artesian aquifers than for the deeper aquifers. FLUCTUATION OF THE PIEZOMETRIC SURFACES Figure 77 shows a hydrograph of well 946-206-1, which taps a secondary artesian aquifer. The water level in the well, which reflects the piezometric surface of a secondary artesian aquifer, rose more than 4 feet between late 1958 and mid 1960. The piezomhetric surfaces of the secondary artesian aquifers fluctuate with the variations in recharge and discharge of the -8 8 1 I 1 1 1 'f I \ \ \ 1 \ II l I I I I I 1 I I I i I i i I I I S87 E 0 86 IWell 946-206-1, a 4.4 miles east of Waldo 85 1958 1959 1960 Figure 77. Hydrograph of well 946-206-1 near Waldo, Florida.

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118 FLORIDA GEOLOGICAL SURVEY aquifers. The piezometric surface of the uppermost secondary artesian aquifer probably fluctuates principally with the water table of the water-table aquifer, and the piezometric surface of the lowermost secondary artesian aquifer probably fluctuates principally with the piezometric surface of the Floridan aquifer. MOVEMENT The water in the secondary artesian aquifers is derived chiefly from the water-table aquifer and from the Floridan aquifer. Water in the secondary artesian aquifers is also discharged chiefly into the water-table and the Floridan aquifers. Where the piezometric surfaces of the upper aquifers are above the piezometric surface of the Floridan aquifer, water seeps slowly downward through the intervening clay layers and secondary artesian aquifers into the Floridan aquifer (fig. 73). Where the piezometric surface of the Floridan aquifer is higher than the piezometric surfaces of the upper aquifers, water seeps upward through the intervening clay layers into the secondary artesian aquifers and the water-table aquifer. WELLS Probably more wells in these four counties draw water from secondary artesian aquifers than from either the water-table or Floridan aquifer. Most of the wells drawing water from these aquifers are used for domestic or stock purposes and are in the areas where the piezometric surfaces of the secondary artesian aquifers are above the piezometric surfaces of the Floridan aquifer. The wells, which are from 2 to 4 inches in diameter, are usually cased only to the first rock below which the material will not cave. The wells are then completed by drilling an open hole below the casing. The amount of water that can be pumped from wells tapping secondary artesian aquifers is limited by the amount that the water level in the well can be lowered before the well fails. Table 6 shows the specific capacities of five wells tapping secondary artesian aquifers in Clay County and four wells tapping secondary artesian aquifers in Alachua County. The specific capacities of these wells indicate that they will produce enough water for domestic use and other small supplies. Supplies adequate for irrigation probably can be developed from some of these aquifers. Permeable beds in the Choctawhat-

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TABLE 6. Specific Capacities of Wells Tapping Secondary Artesian Aquifers numer Remarks -.._ __ ..0 ALACHUA COUNTY --V I Py UG 940-218-1 130 73 4 9.8 48 10 0.2 Do. 940.220-1 68 59 4 15 12 15 1 Do. 940-220-2 60 48 4 I 9.44 12 30 2 Do. 942-206-1 60 60 3 15 1.3 13 2.0 10 Do. 948-200II 124 83 6 38.39 20.12 24.1 6.4 1.2 Do. 2 6D 948-202-8 146 90 6 47.64 1 16.91 32.5 7.6 1.9 Do. CLAY ~ZF»-*

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120 FLORIDA GEOLOGICAL SURVEY chee Formation may yield larger amounts of water in northern and eastern Clay County. In addition, shell beds of Pleistocene and Recent age may provide a dependable but small supply for irrigation in eastern Clay County. FLORIDAN AQUIFER The Floridan aquifer, the most productive aquifer in the four counties, consists-of several hundred feet of interbedded soft, porous limestone and hard, dense limestone and dolomite. The aquifer, which underlies most of the state, consists in these counties of beds of Eocene age (Ocala Group, Avon Park Limestone, Lake City Limestone, and, at least in part, the Oldsmar Limestone), Oligocene age (Suwannee Limestone), and Miocene age (limestones in the lower part of the Hawthorn Formation). These limestones and dolomites, as far as is known, act as a hydrologic unit in these counties. The contours on the map in figure 78 show the approximate elevation and configuration of the top of the Floridan aquifer. From southern and western Alachua County where limestones of the Ocala Group, a part of the Floridan aquifer, are at or near the surface, the aquifer dips to the northeast so that at Orange Park (fig. 78) the aquifer is covered by almost 300 feet of material. Relatively impermeable beds in the overlying Hawthorn Formation confine the water under artesian pressure in the Floridan aquifer. HYDRAULIC PROPERTIES The Floridan aquifer transmits water easier and stores more fresh water than any other aquifer in the four counties. Thej Floridan aquifer, which consists of a thick section of alternating. layers of soft and hard limestone and dolomite, contains fresh water for at least several hundred feet. At a depth, however, which is estimated to be more than 2,000 feet in these counties, the limestones and dolomites probably contain either saline or highly mineralized water. Probably, relatively impermeable layers in the aquifer impede the vertical flow of water. The limestones and dolomites, as a unit, have a high permeability in a lateral direction and a low permeability in a vertical direction. Water in the Floridan aquifer is under both water-table and artesian conditions. In the area west of the dotted line shown on the map in figure 8t) the water in the aquifer is under water-table conditions; and in the area east of this line, the water is under-

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.-I 10 1'0 o o i n. o r. .' .-EI -. 300303 c1e I r,0 L,,,, 4 M X -s-t=-,.70 " ' . ,I ....in * ^ * ' I .l i 1 L I * l l li i i , , Io ggrl , i i i l 50.\' e \ B \ I o o F ran aquifer, >t4 41 o n e o 00w , 0 10951 u nop of the Florida aqufe contours on the top of the Flor~idan aquifer.

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122 FLORIDA GEOLOGICAL SURVEY artesian conditions. The water level in the aquifer is approximately at the base of the confining bed along this line. As the water levels decline the line shifts to the east, and as the water levelsrise the line shifts to the west. The Floridan aquifer transmits water from areas of recharge to areas of discharge, stores water when the recharge exceeds the discharge and releases water when the discharge exceeds the recharge. The coefficient of transmissibility, which is a measure of the capacity of an aquifer to transmit water, is defined as the quantity of water, in gallons a day, that will move through a vertical section of the aquifer 1-foot wide under a unit hydraulic gradient. The coefficient of storage, which is a measure of the capacity of an aquifer to store water, is the volume of water released from or taken into storage per unit surface area of the aquifer per unit change in head. Where artesian conditions exist, the capacity, of an aquifer to store additional water is relatively small, being in the order of several hundred or several thousand times smaller than the capacity of an aquifer where water-table conditions exist. A test for determining the coefficient of transmissibility was made on well 942-216-2, which is about 5 miles northeast of Gainesville. The test consisted of pumping well 942-216-2 at the rate of 350 gpm and of measuring the recovery of the water level in the well after the pumping stopped. (Wenzel, 1942, p. 95-96). The results of this test are shown in figure 79. The coefficient of transmissibility at well 942-216-2 was computed to be 160,000 gpd (gallons per day) per foot. Because well 942-216-2 penetrated only about 200 feet of the aquifer, the coefficient probably is a 0 1 Well 942-216-2 T264= .160,000 gpd/t where, 0 350 Qpm co *s ' 0.56 ft -t -I log cycle I 10 100 1,000 / , ratio of time since pumping started to time since pumping stopped Figure 79. Semilog plot of residual drawdown versus the ratio of the time since pumping started to the time since pumping stopped, showing solution for coefficient of transmissibility.

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REPORT OF INVESTIGATIONS NO. 35 123 measure of the capacity of only the upper part of the aquifer to transmit water. Although the coefficient of storage could not be determined from this test, it is small, being in the order of 0.0001. PIEZOMETRIC SURFACE The contour lines on the map of Alachua, Bradford, Clay, and Union counties in figure 80 represent the approximate height, in feet above sea level, of the static water levels in June 1960 in tightly cased wells penetrating the Floridan aquifer. Thus, in that part of the aquifer where the water is confined, the contours indicate the elevation to which water will rise in a tightly cased well; and in that part of the aquifer where the water is not confined, the contours indicate the elevation of the water table. The surface represented by the contour lines, which was first mapped by Stringfield (1936, pl. 12), is known as the piezometric surface. The most outstanding feature of the map of the piezometric surface in the four counties is the piezometric high that is approximately centered around Keystone Heights. A 90-foot contour encloses an area of about 40 square miles around Keystone Heights, and an 80-foot contour encloses an area of about 360 square miles. East of the 80-foot contour the piezometric surface slopes to an elevation of less than 40 feet in eastern Clay County near the St. Johns River. South of the 80-foot contour the piezometric surface slopes to about 60 feet above sea level near Lochloosa Lake, and west of the 80-foot contour in Alachua County the piezometric surface slopes to an elevation of about 35 feet near the Santa Fe River. North and northwest of the high the piezometric surface slopes to a relatively flat surface of 60 to 70 feet above sea level. This fiat surface includes the western half of Bradford County, the eastern half of Union County, and the northwestern part of Clay County. From the flat surface the piezometric surface slopes to the west to an elevation of about 40 feet in western Union County and to the east to an elevation of about 40 feet in eastern Clay County. A depression in the piezometric surface at Gainesville is probably caused by heavy pumping, and a depression near Green Cove Springs is probably caused by pumping and springflow. RECHARGE Ground water in these counties is replenished by rainfall within the counties. Water recharges the Floridan aquifer by -leaking through the confining beds, by percolating through breaches in the

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124 FLORIDA GEOLOGICAL SURVEY confining beds, and by percolating directly into the aquifer where no confining bed exists. Over most of the four counties water seeps into the Floridan aquifer through the blanket of relatively impervious material that-confines water in the aquifer under pressure (fig. 73). Where' the piezometric surfaces of the upper aquifers are higher than the piezometric surface of the Floridan aquifer, water seeps through the confining beds into the Floridan aquifer. The piezometric sur' faces of the upper aquifers are above the piezometric surface of the Floridan aquifer in Bradford and Union counties and in more than half of Alachua and Clay counties. Where the confining beds have been breached, appreciable' quantities of water may reach the aquifer. Near Gainesville, Hogtown Creek flows directly into the aquifer through Hogtown Sink; and, at one time, Prairie Creek flowed into the aquifer through-Alachua Sink. In addition, water from Orange Lake has been7 observed recharging the Floridan aquifer through a sink in the southwestern part of the lake. At many other places the confining bed has been breached by sinkholes. Breaches in the clay confining beds are indicated by the many sinkholes and lakes dotting the area. These sinkholes form when materials overlying limestone caverns collapse. As the material washes into the sinks, they become partially clogged and' form lakes. A large number of these lakes are in the area of the piezometric high near Keystone Heights. The rate of recharge to the Floridan aquifer in a 525 square mile area of the piezometric high that is enclosed by the 75-foot contour was estimated (fig. 80). The rate of recharge minus the rate of withdrawals in this area is equal to the.rate that water in the aquifer moves across the contour, except for temporary differences due to changes in the amount of water stored in the aquifer. The rate of flow of water across the contour is equal to: Q =TIL Where Q = rate of flow across the contour T = average coefficient of transmissibility across the contour I = average hydraulic gradient across the contour L = Length of contour The average coefficient of transmissibility across the countour" was assumed to be 160,000 gpd per foot, the value obtained from

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45 40' 35 30' 25' 20' 15' 10' 05' 82u00o 55' 50' 4 0' 35 S I I I I I I I I I I I i I I I II I I I I I I I I 1 i I I I I I I I I I 1 1 5 I I I 1 3 40!3 2 _C>O. 4o0_l-3 42_J DUVAL OUNTY N CLAY OUNTY 3 BAKER COUNTY 45'3 6 6 1 COUNTY 2 b4 2< Stake 55!3 43t3 385 • 6 4 .53 39I 5 2 ." I LAKE BUTLER J 7--4t3 S\ A .o49t3 o 61 3 1 D BU 46 t. SAMPTON / _Zo .s 526/ W 6 -t3 2 5 "* 1 42*6WALDO t B E T S 4 EXPLANATION 47 S/ / Lower number is water level * 2\ MELROSE "in feet above mean sea level, S 2 June 1960 cNEWLERAK /. GREN ..... -* Contouer in the Foridan aquifereaston of -50 .the iezomet ic sur e, ine e a bt e 541 3 , HON i5 *V 1 .... 66 Lh/\l conditions and west of the dotted 0 fI 'c,3 MANOPY 5&58 \ \Wt --'3 lie under water-table conditions. F ORUON OUN OT 0 I o 5J I 6 .3 I I I mI9 Se ~en trom US G S oogrophic quodrongles -' do Sto«e Rood Deodpotmgle mops Figure 80. Alachua, Bradford, Clay, and Union counties, Florida, showing contours on the piezometric surface of the Floridan aquifer in June 1960.

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REPORT OF INVESTIGATIONS NO. 35 125 the test on well 942-216-2. The average hydraulic gradient at the 75-foot contour was determined by measuring the area between the 70and the 80-foot contour and by dividing this area by the product of the length of the 75-foot contour, 95 miles, and the decline, 10 feet, of the piezometric surface between the contours. The estimated rate of recharge minus the rate of withdrawals from the Floridan aquifer in the area enclosed by the 75-foot contour was 36 mgd or 56 cfs. The estimated rate of withdrawals in the area enclosed by the 75-foot contour is roughly 9 mgd or 14 cfs. The estimated rate of recharge in the area within the contour is therefore 45 mgd or 70 cfs. This rate of recharge is equal to about 1.8 inches of water per year over 525 square miles. The actual rate of recharge to the aquifer is probably higher than the rate of recharge that was estimated in the above manner. -The coefficient of tranpsmissibility that was used in the computation is probably less than that of the entire aquifer because the coefficient was determined from a test on a well that penetrated only the upper 200 feet of the aquifer. Large quantities of water, moreover, may have moved across the contour through solution channels. The estimated rate of recharge, though probably low, shows that large amounts of water enter the Floridan aquifer in the area of the piezometric high and that the amount is probably not less than 45 mgd. Another area in which large amounts of water enter the Floridan aquifer is a 300 square mile area in southern and western Alachua County where limestones of the Ocala Group are at or near the surface (fig. 4). In this area water percolates downward as shown by the absence of surface drainage. Of the rain that falls in southwestern Alachua County, part is evaporated from the surface of the land, part is transpired by vegetation, and the remainder percolates to the water table. The rainfall in southwestern Alachua County was about 67 inches in 1959. This rainfall is the average of the measured rainfall at the Florida Forest Service's Archer and Forest Grove rain gages after the measured rainfall at these gages had been multiplied by a coefficient to make the rainfall compatible with that measured by nearby U. S. Weather Bureau gages. The evapotranspiration in southwestern Alachua County was computed according to Thornthwaite's method to be about 40 inches in 1959 (Thornthwaite and Mather, 1955, p. 22-23). The remainder of the water, about 25 inches, percolated to the water table. The average rate of recharge in southwestern Alachua County is doubtless less than the rate of recharge in 1959. The average

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126 FLORIDA GEOLOGICAL SURVEY rainfall at Gainesville is 51 inches per year; whereas, the rainfall in southwestern Alachua County was 67 inches in 1959. The average rate of recharge is estimated to be at least 10 inches per year. If the average rate of recharge were 10 inches per year, the average rate of recharge in southwestern Alachua County would be almost one-half mgd per square mile. DISCHARGE Of the hundreds of millions of gallons of water a day that enter the Floridan aquifer in the four counties, only a part is discharged in the counties. A large part, moving in the direction of the hydraulic gradient, is discharged outside these counties through the aquifer. The contours of the piezometric surface (fig. 80) show that the piezometric surface is lower in all adjacent counties except possibly Putnam, Baker, and Columbia. Ground water that does not leave the area through the aquifer is discharged from the aquifer by leakage into the upper aquifers, flow from springs, flow into lakes and streams, or is withdrawn through wells. Water is discharged from the Floridan aquifer into lakes and streams in the southern and western part of Alachua County where the Floridan aquifer is at or near the land surface. In the southern part of Alachua County ground water is discharged into a few of the lakes that occupy depressions in the Floridan aquifer. Lochloosa Lake is, in part, fed by water from the Floridan aquifer; and, at times, Orange Lake probably receives water from the Floridan aquifer. A large part of the water, however, moves from the area to be discharged into streams that have cut into the aquifer. A large amount of water is discharged from the Floridan aquifer into the Santa Fe River. The Santa Fe River, which flows for several miles underground near High Springs, is fed by ground water during periods of low flow, but water moves from the river into the Floridan aquifer during periods of rising river stages and re-enters the river during periods of falling river stages (Cooper, Kenner, and Brown, 1953, p. 150-151, pl. 9.4, 9.5). Furthermore, hundreds of millions of gallons of water a day flow from the Floridan aquifer into the Santa Fe River between 'the gaging stations near High Springs and Fort White. Water leaks into the upper aquifers where the piezometric surface of the Floridan aquifer is higher than the water table or artesian pressures of the upper aquifers (fig. 73). Upward leakage occurs in the low areas along the St. Johns River, in the valleys'

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REPORT OF INVESTIGATIONS NO. 35 127 of Black Creek and its tributaries, and near Lochloosa Creek. In these areas water also moves up in wells that tap the Floridan and are not cased off by the upper aquifers. Foster (1961) estimated that in eastern Clay County about 30 mgd moves from the Floridan into the upper aquifers through wells. Water escapes from the Floridan aquifer through many springs. Poe Springs, which is near the town of High Springs, has the largest flow of any spring in the area. The flow of this spring has been measured to be as little as 20 mgd and to be as much as 59 mgd. Other springs in the area that seem to derive their flow from the Floridan aquifer are Green Cove Springs and Wadesboro Springs in Clay County and Magnesia Springs in Alachua County. DISCUSSION OF FLORIDAN AQUIFER BY COUNTIES ALACHUA COUNTY Fluctuation of piezometric surface: Figure 81 shows hydrographs of six wells tapping the Floridan aquifer in Alachua County. These wells are in or near the area where the Floridan aquifer is at or near the surface (fig. 4). The water levels in these wells fluctuated from 4 to 8 feet between late 1958 and mid 1960. The fluctuations were caused chiefly by changes in the rate of recharge to and discharge from the aquifer, owing to fluctuations in the rate of rainfall and in the rate of. evapotranspiration. A hydrograph of well 948-231-2, which is 1.5 miles northwest of Alachua, and a hydrograph of well 949-236-2, which is at High Springs, is shown in figure 82. The sharp rise in the water levels of the two wells in March 1959 was probably caused in part by a high stage of the Santa Fe River. Area of artesian flow: Artesian wells will flow where the piezometric surface is higher than the land surface. Figure 83 shows the approximate area in Alachua County in which wells tapping the Floridan aquifer would flow in June 1960. The area includes the low land along Lochloosa Creek and extends from Lochloosa Lake to State Highway 20. The area also includes the low land adjacent to the east and west shores of the lake. Wells will also flow in the eastern part of Orange Lake or in the prairie east of Orange Lake, which was once a part of the lake. Analysis of pumping test: The results of the pumping test on well 942-216-2, which is about 5 miles northeast of Gainesville, showed that at well 942-216-2 the coefficient of transmissibility of

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128 FLORIDA GEOLOGICAL SURVEY 62 Well 927-203-1,10 miles south of Hawthorne Well 929-213-1, 3.5 miles S56 -------east of Micanopy S54 52 Well 932-231-1, at/Well 941-222-2, Archer 3 miles northwest of "o \ oinesville 50 -4 8. " Well 936-236-1, 2.5 miles south of Newberry ^ 46 44 ell 946-226-2, 3 miles i southeast of Alachua 42 J FMAMJ JASONDJ FMAMJJ ASONDJ FMMJJ J ASO ND 1958 1959 1960 Figure 81. Hydrographs of wells 927-203-1, 929-213-1, 932-231-1, 936-236-1, 941-222-2, and 946-226-2 in Alachua County, Florida. the upper part of the Floridan aquifer is about 160,000 gpd per foot. The water in the Floridan aquifer at well 942-216-2 is under artesian conditions; therefore, the order of magnitude of the coefficient of storage of the aquifer at well 942-216-2 is about 0.0001. Figure 84 shows a graph of the theoretical drawdown in an infinite aquifer in the vicinity of a well from which water is being withdrawn at the rate of 1,000,000 gpd from storage within the"

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REPORT OF INVESTIGATIONS NO. 35 129 41 40 S/Well 948-231-2, 1.5 miles northwest of Alachua 0 E 38 0 S37 -36 35 "0 Well 949-236-2, at 34 High Springs 1958 1959 1960 Figure 82. Hydrographs of wells 948-231-2 and 949-236-2, in Alachua County, Florida aquifer (Theis, 1935, p. 519-524). The aquifer is assumed to have a coefficient of transmissibility of 160,000 gpd per foot and a coefficient of storage of 0.0001. The drawdown is proportional to the rate of pumping. If the well were being pumped at the rate of 100,000 gpd, for example, the drawdown would be one-tenth of that shown in figure 84. One of the assumptions on which the drawdowns shown in figure 84 are based is that the water being withdrawn from the well is derived from storage in the aquifer. Actually, the drawdown will stabilize when the cone of depression has induced enough additional recharge or intercepted enough natural discharge to

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130 FLORIDA GEOLOGICAL SURVEY 8215' 10' 05' 82001' 29 237' 1 1 I 1 I l I I I I 1-1 -29°37' HAWTHORNE 030 EXPLANATION 25' \0 N M O. 25' Area oal 0 1 2 3 4 5 miles 29023' !1 I I I I 1 29023' 82015' I0' 05' 82°01' Figure 83. Southeastern Alachua County, Florida showing the approximate area of artesian flow in June 1960. equal the rate at which water is being withdrawn from the well. How long a well in this area must be pumped before the drawdown in the well will stabilize was not studied, but it is probably less than a year and doubtless less than 10 years. When more than one well is being pumped, well interference results. Well interference refers to the fact that pumping one well causes a drawdown or a lowering of the water level in nearby wells. The magnitude of the interference between wells depends upon many factors; but, in general, the interference is large where wells are closely spaced and small where they are far apart. The magnitude of the interference between wells, in fact, varies more or less with the logarithm of the distance between the wells. For

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REPORT OF INVESTIGATIONS NO. 35 131 0 Computation based on. 2 Discharge (0)1,000.000gpd Transmissibility (T) * 160,000 gpd/ft. 3 -Storage IS). I X --3.~^--sldoo -----16 C 7 0.1 1 10 100 1,000 10,000 Distance, in feet from pumping well Figure 84. Graph showing theoretical drawdowns in the vicinity of a well pumping 1,000,000 gpd for selected periods. example, as can be determined from figure 84, if two wells spaced 1,000 feet from each other are pumped at the rate of 1,000,000 gpd each for a day, the drawdown in each well would be increased about 3 feet because of the pumping of the other well. Specific capacities of wells: Table 7 lists the specific capacities of 23 wells in Alachua County. The specific capacities of wells in western Alachua County generally were higher than the specific Scapacities of wells in central and eastern Alachua County. The Sspecific capacities in western Alachua County ranged from 29 to S20,000 gpm per foot of drawdown; whereas, the specific capacities of wells in central and eastern Alachua County ranged from 2 to 700. -Some of the wells, especially those with very high specific caiacities, probably penetrate cavities. Most of the wells having comparatively low specific capacities are in central or eastern Alachua County and tap less than 100 feet of the aquifer.

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TAUBL 7. Specific Capacities of Wells Tapping the Floridan Aquifer in Alachua County, Florida nu er Remarks 080-216-1 67 55 4 81.6 2 10 .... 5 Reported by driller 986-286-1 251 186 8 25.57 20.70 590 7.00 29 Measured by USGS 087-205.1 205 110 * 8 34 4.8 350 8 70 Reported by owner 987.205-1 205 110 8 34 4.5 350 .5 80 Measured by USGS 987-219-1 870 116 16 50 10 250 -... 25 Reported by driller 987-282-1 144 90 10 40.70 .20 400 .8 2.000 Measured by USGS; pumping level seemed to have stabilized 988-217-1 79 50 3 81 3 10 -3 Reported by driller 938-219-4 407 -_ 18 -16 1,000 -60 Do. 988-219-6 464 178 30 98.2 7 5,100 -700 Do. 988-219-8 748 152 24 95.24 12.7 4,300 6.6 840 Do. 988-219-9 750 168 24 88.23 12.0 4,500 6.8 880 Do. 988-221-1 916 290 20 32.8 5 3,200 -600 Do. 988-221-2 700 ;88 20 25.5 7 2,700 -400 Do. 088-236-2 120 80 12 88.40 0.08 500 0.2 20,000 Measured by USGS 940-217-1 368 205 10 117 22 500 -20 Reported by driller 940-221-2 814 167 .6 128.71 14.19 100 4.8 7 Measured by USGS 941-220-1 195 121 4 121 6 20 -3 Reported by driller

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TABLE 7. (Continued) 942-216-8 522 158 20 90.10 1 2,000 -40 Reported by driller 98207-1 1i0 9° 4 81 6 1 2 Do. a a a 94i.216-2 350 160 12 87.84 10.22 850 7.7 34 Measured by USGS 942-216-8 522 1658 20 90.10 61 2,000 -40 Reported by driller 943-207-1 160 95 4 81 6 15 -2 Do. 0 047-210-1 255 175 6 80.89 1.8 850 .4 190 Measured by USGS 949-285-2 800 250 10 87.84 .26 420 .6 1,600 Measured by USGS; pumping level seemed to have stabilized 951-285-1 225 48 4 14.14 .02 25 .1 1,000 Reported by 4riller P Co Co

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134 FLORIDA GEOLOGICAL SURVEY BRADFORD COUNTY Fluctuation of the piezometric surface: Although no water levels in wells tapping the Floridan aquifer in Bradford County have been measured for a significant period of time, the piezometric surface in Bradford County probably fluctuated approximately the same as the piezometric surface in nearby counties. The piezometric surface in Bradford County, in other words, probably fluctuated 3 or 4 feet in 1959 and 1960. Specific capacities of wells: Table 8 gives the specific capacities of several wells tapping the Floridan aquifer in Bradford County. The specific capacities ranged from 25 to 210 gpm per foot of drawdown and averaged 78. CLAY COUNTY Fluctuation of the piezometric surface: Figure 85 shows the decline of the piezometric surface in northeastern and eastern Clay County between June 1934 and June 1960. Figure 86 shows the fluctuation of the water level in four wells tapping the Floridan aquifer in Clay County. Most of the decline in the water levels is probably due to withdrawals from wells in the Jacksonville area. The decline in the water levels, as shown in figure 86, began in about 1948 and continued until about 1956. Since 1956, the water levels have risen 3 or 4 feet. The decline from June 1934 to June 1960 was about 18 feet in Orange Park and about 14 feet near Green Cove Springs. Area of artesian flow: The area in Clay County in which wells tapping the Floridan aquifer will flow is shown in figure 87. The area was determined by comparing the elevation of the land surface from topographic maps with the elevation of the piezometric surface as shown in figure 80. As may be seen from figure 87, the principal areas of artesian flow are along the St. Johns River and in the low areas near Black Creek and its tributaries. Most of northeastern Clay County, including those low areas near Black Creek and Little Black Creek, is in the area of flow. This area extends along Black Creek and up North Fork Black Creek. It also extends along South Fork Black Creek and along Greens Creek. Specific capacities of wells: Table 9 gives the specific capacities of 33 wells in Clay County. The specific capacities were lower in eastern and northeastern Clay County than they were in western

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TABLE 8. Specific Capacities of Wells Tapping the Floridan Aquifer in Bradford County, Florida 965-219-1 175 11 1 78.01 .70 150 0.5 210 Measured by USGS I 956-206-6 503o 28 1 93.19 10 600 .., 60 Reported by driller 0 Well 7 20 9 4 48 00 * 60 Remarksul number 1 p 90-219-1 175 117 10 78.01 .70 150 0.5 210 Measured by USGS; pumping level seemed to have stabilized 0956-206-6 503 278 10 93.19 10 600 .. 60 Reported by driller 002-208-1 725 830 16 180 40 2,200 3.8 5 Measured by USGS P pumping level seemed to have stabilized 008-203-1 774 442 16 125.51 36.22 2.200 .5 61 Do. S008-211-1 700 275 12 --18.1 1,000 .2 76 Do. CT Ot

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136 FLORIDA GEOLOGICAL SURVEY 82"C' 82*00' 55' 50' 45 40' 35' 8'*030' I I I I I IIII I I I I 30 15' -5 -10 --20 DUVAL COUNTY N CLAY COUNTY tlANE S .4 -3' o u051 NGL N CS -3VE -30.00' 1rsi p o r srce ~Qn feet; " --E IO V .9's / We14 SContour line connects points of equal decline in the piezometric -surface from June 1934 to -40o -June 1960. Dashed line represents inferred position of contour Contour interval 5 feet -40 2 4 5 mile Figure 85. Clay County, Florida, showing the decline of the piezometric surface in eastern Clay County from June 1934 to June 1960. Clay County. The specific capacities of wells in eastern and northeastern Clay County ranged from 2 to 60 gpm per foot of drawdown and averaged 12; whereas the specific capacity of wells in western Clay County ranged from 22 to 300 gpm per foot of drawdown and averaed 120. June 1960. Dashed line repreaveraged 120.0

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REPORT OF INVESTIGATIONS No. 35 137 72 6 --.. Well 003-151-1,--S/ oat Middleburg 68-. -4 Q ."J \\ "2s 1 Well 006-149-C, I o 3 miles northeast of Middleburg 56--S48 -.Wel 002 -Well 002-142 -1,. 2.5 miles north of Green Core Springs 44 I I ------40-36 Well 959-140-1, at Green Cove Springs 28------1 1 1 1 _ 1935 1940 1945 1950 1955 960 Figure 86. Hydrographs of wells 959-140-1, 002-142-1, 006-149-1, and 003-151-1 in Clay County, Florida. UNION COUNTY Fluctuation of piezometric surface: The piezometric surface in Union County fluctuates chiefly with variations in rainfall. As shown in figure 88, the water level in well 007-222-1, which reflects the piezometric surface in the Floridan aquifer, fluctuated about 4 feet during 1959 and 1960 in response chiefly to variations in rainfall. Specific capacities of wells: Table 10 gives the specific capacities of seven wells in Union County. The specific capacities ranged from 60 to 360 gpm per foot of drawdown and averaged 145.

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138 FLORIDA GEOLOGICAL SURVEY 8,a, a' e82*' ' ' 5s45' 40' 35' 8 30 3C-s _ I I I I I I I 1 I I I I I I I I I I I I I I I I I I I I I I 1 t_ ' DUVAL COUNTY SLAY COUNTY ORANG 50 , ,c,,,, .., ." gEXPLANATION 4' j Areo where wells topping the --oFloridan aquifer will flow .. 45 a: Ii 5 5940' < 7 82 S 82"00 55' 5 45' 40 35' 8 o' Figure 87. Clay County, Florida showing the approximate area in which wells tapping the Floridan aquifer will flow, June 1960. QUALITY OF GROUND WATER Just as the quantity of ground water is variable, so is its quality. Both nature and man affect the amount of the matter dissolved in the ground water of the area. Water dissolves minerals from the earth's crust; the amount and kind of dissolved material depends on time of contact and the composition of the earth's crust. Man's use of water and land affect both the chemical and the sanitary quality. This report is concerned only with the

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REPORT OF INVESTIGATIONS No. 35 139 chemical and physical quality and contains no information on the sanitary aspects and suitability for use when such is related to bacteriological quality. FACTORS AFFECTING CHEMICAL QUALITY Generally rain contains a small amount of dissolved matter, mostly dissolved gases such as nitrogen, oxygen, and carbon dioxide. In coastal areas much sodium chloride may be carried by rainfall and windblown spray. The solvent action of water is greatly increased by the presence of carbon dioxide which is absorbed from the atmosphere and from the soil. The amount and type of mineral matter taken into solution by water depends, among other things, upon the availability of carbon dioxide for the weathering process, the nature of the minerals present, and the length of time the water is in contact with the minerals. The longer the water is in contact with a given soil or rock, the more mineralized it becomes. The solution of material is often further affected by the biological activity of plants and soil bacteria. Demand for water for industrial and domestic use will increase as the area develops. Increased use and re-use of the water can logically be expected to affect the chemical quality of ground water. Therefore, it is evident that both manmade factors and natural factors cause variations in the quality of ground water. The chemical quality data are considered a good evaluation of the ground-water quality at the time of sampling. The data do not show the variation of quality with time. There are indications that variation with time is significant in a few places. Ground-water quality is discussed by aquifer; water-table aquifer, secondary artesian aquifer, and Floridan aquifer. WATER-TABLE AQUIFER Residue on evaporation at 180°C was determined on all samples with color intensity exceeding 10, and on 24 additional samples with color intensity less than 10 units. Of the 119 samples from wells drawing water from the water-table aquifer, the color intensity of 12 samples was greater than 10 units. In the other samples (color intensity no greater than 10 units), the concentrations of mineral matter were calculated from partial analyses and assumed to be approximately equal to the residue on evaporation at 180°C. The calculated and determined mineral matter ranged from 17 to 302 ppm. The sum of the determined constituents is

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TABLE 9, Specific Capacities of Wells Tapping the Floridan Aquifer in Clay County, Florida Well. u. Remarks number a P it 8) r 6 046-202.4 492 180 8 61.27 18 550 1 80 Reported by driller 949-158-1 450 .... 10 .... 4 1,200 2 800 Reported by owner 049-158.2 460 218 10 -4 1,140 2 300 Do. .950.187-2 400 .4 +14 14 23 .1 2 Measured by USGS 051-187-1 860 80 6 +10 19 160 .1 8 Do. 053-138-1 494 274 4 +25 24 240 .1 10 Do. 956-139-1 ' 89 200 6 +16 10 180 .1 20 Do. 956-158.2 580 858 10 88 23.5 800 _ 84 From records of U.S. Army 956-159-1 718 312 10 151 10 800 _ 80 Do. 956-i5092 695 292 12 117 20 800 -40 Do. 9566159-8 581 316 10 84.5 5 800 -160 Do. 957-157-1 680 877 10 78.0 36 800 -22 Do. 958-189-1 650 276 8 to 6 +16 19.5 500 .7 26 From records of U.S. Navy 958-157-1 685 342 12 74 8.5 800 -280 From records of U.S. Army 958-158il 661 380 10 91.0 4.5 800 -180 From records of U.S. Army 958-158-2 719 376 10 86.0 27 800 -30 Do.

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TABLE 9. (Continued) iii ., Well ia Stg aE "Remarks number ...p 958-160-1 524 -12 117 4 800 -80 Do. 959-141-3 605 420 12 10 46 1,000 -22 Reported by driller 002-142-1 400 72 6 +81 81 140 0.1 5 Measured by USGS 008-145-2 479 -8 to 2 +26 25 60 .1 2 Do. 004.149-1 675 -4 to 8 +40 37 220 .1 6 Do. 004-150-1 475 -8 to 2 +50 40 120 .1 8 Do. 005-141-1 525 -8 to 2 +26 25 80 .1 8 Do. 005-146-2 496 -6 +26 24 600 .1 20 Do. 006-147-1 850 219 8 +86 84 180 .1 5 Do. 006-149-1 481 80 4 +27 26 860 .1 15 Do. 006-149-2 580 157 4 +22 21 200 .1 10 Do. Co 006-160-2 600 200 2 +28 22 70 .1 3 Do. 01 009-142-1 450 ... 3 +26 25 100 0.1 4 Measured by USGS 009-142-2 600 296 6 +85 8 0 915 80 Reported by driller 010-142-1 450 815 3 to 2 +22 22 40 2 2 .Measured by USGS 010-142-2 450 300 4 +34 80 60 G 2 Do. 010-142-4 405 336 8 ..... 1,800 .. 60 Reported by driller

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142 FLORIDA GEOLOGICAL SURVEY 67 -66 o c 65 E S064 0 S63 6I Well 007-222-1, ) ' 8 miles north of Lake Butler -62 61 15 S Monthly Rainfall at "o High Springs -10 X 0 ' / / ' , / 1958 1959 1960 Figure 88. Hydrograph of well 007-222-1 in Union County, Florida, and a graph of monthly rainfall at High Springs, Florida greatest in the northern part of the area and least in the southwestern and southeastern parts (fig. 89). Silica was determined in 120 of the same samples. The concentration of silica was equal to or less than 10 ppm in 85 of the 118 samples. The concentrations ranged from 0.0 to 58 ppm. Samples collected from iron determinations were filtered in the field. The concentrations ranged from 0.01 to 6.4 ppm. Concentrations of iron in 46 of the 119 samples exceeded 0.30 ppm.

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TABLE 10. Specific Capacities of Wells Tapping the Floridan Aquifer in Union County, Florida nu er .c Remarks 957-228-2 291 103 10 78.85 1.98 600 0.60 800 Measured by USGS; r pumping level seemed ' to have stabilized 957-227-1 330 125 10 87.49 9.86 600 .27 60 Do. 001-219-1 857 .12 66.89 10 600 -60 Reported by driller 001-219-1 857 -12 66.89 5.60 600 .25 110 Measured by USGS w 001-210-2 402 30 10 60 6 350 -60 Reported by driller P 004-211-1 612 280 12 to 10 71.6 19.6 1,386 -_ 70 Do. 0c 007-222.1 724 694 8 87.90 .94 340 16.6 360 Measured by USGS; : pumping level seemed to have stabilized I-a

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144 FLORIDA GEOLOGICAL SURVEY S i LAWTEY C -pp' /00 ( ANG PENNEY I EA L \ -cSTARKE c -GREEN r \ --^ EXPLANATION A Lines connect points of approximate GAINESVILLE equal dissolved solids. Contour SNWB Y interval 50 ports per million. SLochlosa I -_ ARCHER Lake % o ORANGE ,UNION PARK ti 100 / LAKE LAWTEY C LAY ' -^ ./ / ( hC1GSLEY FARIS * ' -STARKL A0 ,M a GREEN GAINESfVILL"E Lines connect points of opproximote equal hardness Haordness is ex-pressed as CaCO3 in pars per Loh s million Contour interval 100 ppm L BRADE0RCHER . -Lo.BWOOKER i ALACHUA -Figure 89. Dissolved solids and hardness of water from the water-table a 1ifer. Lochboo i so -ARCHER L ei I

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REPORT OF INVESTIGATIONS NO. 35 145 Hardness ranged from 3 to 246 ppm. Of the 117 hardness values determined, 73 were less than 50 ppm, 12 were between 50 and 100 ppm, and 32 were greater than 100 ppm. The water in the northern part of the area is most likely to be hard (fig. 89). The hardest water entered the water-table aquifer from the underlying secondary artesian aquifers. Sodium was estimated or determined to be 10 ppm or less in 23 of the samples. Estimated and determined sodium concentrations ranged from about 1.5 to 62 ppm. Some samples contained unusual concentrations of potassium; concentrations range from 0.0 to 29 ppm. Some samples containing unusual concentrations of potassium have rather high concentrations of nitrate. Bicarbonate is often the dominant substance in water samples from the water-table aquifer, and also from the secondary artesian aquifers and the Floridan aquifer. The concentrations of bicarbonate ranged from 0 to 324 ppm. Of the 121 samples from the water-table aquifer, 39 contained bicarbonate in excess of 100 ppm. Sulfate concentrations were 10 ppm or less in 40 of the 56 samples-concentrations ranged from less than 1 to 72 ppm. Chloride ranged from about 1.5 to 92 ppm. Chloride was 10 ppm or less in 35 of the 71 samples. Fluboide exceeded 1.5 ppm in 6 of the 118 samples and ranged from 0.0 to 3.1 ppm. Nitrate concentrations ranged from 0.0 to 119 ppm. Nitrate concentrations in 33 of the 61 samples were 1.0 ppm or less and exceeded 10 ppm in 17 samples. SECONDARY ARTESIAN AQUIFERS Residue on evaporation at 180°C was determined for all samples with color intensity exceeding 10 units. Of the 144 samples taken from wells drawing water from the secondary artesian aquifers, the color intensity of 4 samples was greater than 10. In the other samples (color intensity no greater than 10), the concentration of mineral matter was calculated from partial analyses and assumed to be approximately equal to the residue on evaporation at 180°C. The calculated and determined mineral matter ranged from 29 to 363 ppm. Mineral content of the water is greatest in the vicinity of Starke (fig. 90). Silica was determined in 143 of the same samples. The concentration of silica was equal to or less than 10 ppm in only

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146 FLORIDA GEOLOGICAL SURVEY UNION ' \f A\ \ I PENNEY I o \ KINGSLEY FS * 200 ' AL ACHUA iGAaLIVEU EXPLANATION .-^-Sr sky 'S --Lines connect points of approximate IM equal dissolved solids. Contour L -...^G., ARCH'ER\ tE I ftinrvo 50 ports I/r inihon ORANGE i .n.-lv * y T--"PARK ,o UNION a 50 p /SoA ,FORD 2o00 I e O ERALACHUA NeweeRRY 'GAiNE '' EXPLANATION N/ W a /0 Lines connect points of approximate , Lrhozo equal hordness Hardness is ex-L -i.. * ACe1R 4? 0^ pressed os CoCOs in parts per million Contour interval 50 ppm. Figure 90. Dissolved solids and hardness of water from the secondary artesian aquifers.

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REPORT OF INVESTIGATIONS No. 85 147 23 of the 143 samples. The concentrations ranged from 0.5 to 73 ppm. Samples for iron determination were collected in separate containers after filtering with millipore filters. Concentrations ranged from 0.02 to 3.9 ppm. Concentration of iron in 23 of the 140 samples exceeded 0.30 ppm. Hardness ranged from 4 to 248 ppm. Of the 143 hardness values determined, 8 were less than 50 ppm, 31 were 50 to 100 ppm, and 104 were greater than 100 ppm. In general, the hardest water occurs in the northern part of the area (fig. 90). Sodium was estimated or determined to be 10 ppm or less in 2 of 22 samples. Estimated and determined sodium concentrations ranged from about 4.2 to 56 ppm. Bicarbonate is often the dominant substance present in water samples from the secondary artesian aquifers, and also from the water-table aquifer and the Floridan aquifer. The concentrations of bicarbonate ranged from 14 to 326 ppm. Of the 143 samples from the secondary artesian aquifers, 110 contained bicarbonate in excess of 100 ppm. Sulfate concentrations were 10 ppm or less in 59 of the 66 samples. Concentrations ranged from 0.0 to 12 ppm. Chloride ranged from about 4.5 to 84 ppm. Chloride was 10 ppm or less in 16 of the 35 samples. Fluoride exceeded 1.5 ppm in 6 of the 142 samples. The concentrations ranged from 0.0 to 2.1 ppm. Waters containing fluoride in concentrations greater than 1.5 ppm were from wells in Clay County. Nitrate concentrations ranged from 0.0 to 37 ppm. Nitrate concentrations in 8 of the 15 samples were 1.0 ppm or less and 10 ppm or greater in 2 samples. FLORIDAN AQUIFER Residue on evaporation at 180°C was determined for all samples with color intensity exceeding 10 units, and for 22 additional samples with color intensity less than 10. Of the 244 samples taken from wells drawing water from the Floridan aquifer, the color intensity of 8 samples was greater than 10. In the other samples (color no greater than 10), the concentration of mineral matter was calculated from partial analyses and assumed to be approximately equal to the residue on evaporation at 1800C. The calculated and determined mineral matter ranged from 33 to 687 ppm. The highest concentration of dissolved solids occurs

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148 FLORIDA GEOLOGICAL SURVEY south of Gainesville. Water in southeastern Clay County is also high in dissolved solids (fig. 91). Silica was determined in 241 of the same samples. The concentrations of silica were equal to or less than 10 ppm in 60 of the 241 samples. The concentrations ranged from 0.2 to 51 ppm. Samples collected for iron determinations were filtered in the field. Concentrations ranged from 0.00 to 7.3 ppm. Concentrations of iron in 23 of the 231 samples exceeded 0.30 ppm. Hardness ranged from 10 to 519 ppm. Of the 239 hardness values determined, 9 were less than 50 ppm, 66 were 50 to 100 ppm, and 164 were greater than 100 ppm. The water from the Floridan aquifer is fairly uniform in hardness. Hardness exceeds 200 ppm in a small area in southeastern Clay County and in northwestern and southern Alachua County (fig. 91). Sodium was estimated or determined to be 10 ppm or less in 28 of the 47 samples. Estimated and determined sodium concentrations ranged from about 3.5 or less to 92 ppm. Some samples contained unusual concentrations of potassium; concentrations ranged from 0.1 to 8.9 ppm. In some samples containing unusual potassium concentrations, nitrate concentrations were rather high. Bicarbonate is often the dominant substance present in water samples from the Floridan aquifer, and also from the secondary artesian aquifers and the water-table aquifer. The concentrations of bicarbonate ranged from 21 to 430 ppm. Of the 243 samples from the Floridan aquifer 180 contained bicarbonate in excess of 100 ppm. Sulfate concentrations were 10 ppm or less in 88 of the 148 samples. Concentrations ranged from 0.4 to 344 ppm. Chloride ranged from about 2.5 to 145 ppm. Chloride was 10 ppm or less in 52 of the 82 samples. Fluoride exceeded 1.5 ppm in 1 of the 240 samples. The concentration ranged from 0.0 to 2.2 ppm. Nitrate concentrations ranged from 0.0 to 60 ppm. Nitrate concentrations were 1.0 ppm or less in 43 of the 51 samples and 10 ppm or greater in 3 samples. VARIABILITY OF WATER QUALITY The variation in water quality within the aquifer is due mostly to natural factors. Concentration of dissolved substances generally increases progressively with depth to near the bottom of the

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REPORT OF INVESTIGATIONS No. 35 149 ----..ARI t. . , UN ION /_.. / j C Y S\LAKE LWIY BRY BULER CIL EXPLANA S \ IY FARIN5LE -tMS soon? AIDFOI I r^.&s r------]^ ^U ----^ H Ie \--I t S U LAC 1 iJ N RINGSRa INSvE LANAT N I -NEWBERRY\ a" Lo;ee $Ak, I E /50 l SI I S Lines connect points of approximate *I fh\ ,iL ._ Qequal dissolved solids Contour L. ARC E R te interval o5 parts per million, a\00 ( \ bT~B UT LLER CLAY (I / INGSLEY FARMS *00 STARK(E R N' $4-v BRA D IFORIh LD IM SPRINGS River I --KEYSTONE HEIGHTS -./ Sonia e J, A L A C U A *NEWBERRY GAINESVILLE "6 EXPLANATION s | Lines connect points of opproximate it ioOS Lakeo equal hardness. Hardness is ex-L.. -* ARCHER pressed as CoCO3 in ports per Ji' |million, Contour inlervol 100 ppm. Figure 91. Dissolved solids and hardness of water from the Floridan aquifer.

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150 FLORIDA GEOLOGICAL SURVEY Hawthorn Formation. Then the concentration of dissolved substances decreases, reaching a minimum in the Ocala Group and Avon Park Limestone, and possibly in the Lake City Limestone. These trends in concentration appear related to different recharge rates, to solubility of geologic materials, and in some places to upward movement of artesian water from the Floridan aquifer. The depth at which the concentration of dissolved substances increases continuously with increasing depth was not observed in the area. The deepest well from which a sample was analyzed is 850 feet. The well is at Green Cove Springs, is cased to 400 feet, and had 139 ppm of dissolved substances in the water. The variation in the type of dissolved substances and their concentration appears to be associated with major formational changes. For example, a marked increase in calcium and sulfate was observed in the zone near the top of the Ocala Group and near the top of the Avon Park Limestone. The calcium and sulfate are apparently dissolved from gypsum sediments. Silica in water tends to increase with depth at least to the bottom of the Hawthorn Formation. Sands, clays, and limestones are potential sources of silica. The weathering of clays may explain the trend of higher silica concentrations with depth. The iron in the water, besides being localized, tends to decrease with depth. Probably the most important iron-dissolving environments are biological activity and decaying organic matter, producing abundant carbon dioxide to enrich percolating water, although other favorable iron-dissolving environments are possible. The detailed chemistry of iron is complex and has been the subject of recent researches (Hem, 1960a, 1960b, 1960c; Hem and Cropper, 1959; Hem and Skougstad, 1960; and Oborn, 1960a and 1960b). Generally the concentration of calcium plus magnesium in water from limestone is chemically equivalent to the amounts of carbonate plus bicarbonate. If the water is from a zone enriched with gypsum sediments, the concentration of calcium plus magnesium is in general chemically equivalent to the sum of carbonate, bicarbonate, and sulfate. Whereas the solubility of calcium and magnesium carbonates in water depends on the presence of dissolved carbon dioxide, the solubility of calcium sulfate is relatively unaffected by its presence. Gypsum is not the only source of sulfates in water. The action of certain bacteria on sulfur-bearing compounds produces watersoluble sulfates. Sodium and potassium differ markedly in at least one geochemical aspect. Potassium is absorbed by clays at a considerably more

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REPORT OF INVESTIGATIONS No. 35 151 rapid rate than sodium. The area contains many clay deposits; therefore, one would expect water of the total mineral content found in this area to contain no more than 1 or 2 ppm potassium. Greater concentrations are probably caused by man. Sodium and chloride in water can be of either natural or manmade origin. For the most part they are probably of natural origin. Sodium tends to increase slightly with depth. Low concentrations of nitrate are common in water. In concentrations greater than 10 ppm, it is probably caused by man. Nitrate concentration decreases with depth. In the Floridan aquifer only about 1 percent of the water samples contained nitrate in excess of 10 ppm. The greater and more frequent concentrations of nitrate at shallow depths is further evidence of its origin from man-made factors. Color is more prevalent and intense at shallow depths. It is caused by the presence of organic matter leached from vegetation or peat beds. Swamp areas are the principal contributors to color of water. For most water uses, the objectionable quality characteristics of water from the water-table aquifer are probably iron, calcium and magnesium hardness, and nitrate-in certain localized areas. Although apparently not extensive, color in water from the watertable aquifer is troublesome in certain localities. Iron concentrations greater than 0.30 ppm are less frequent in the water-table aquifer than in the secondary artesian aquifer and therefore the water from the water-table aquifer is of better quality for most uses. Secondary artesian aquifer water is harder but less colored than water-table aquifer water. In the Floridan aquifer, both water supply and water quality are generally better than that in the other aquifers. Hardness is the most frequent undesirable characteristic. Objectionable concentrations of iron for most uses are infrequent. Sulfate may be at objectionable levels in a few places. The water is colored by organic substances in only a few places. Some wells may be cased to avoid water containing undesirable concentrations of constituents. GROUND-WATER TEMPERATURE The temperature of ground water is not so variable as that of surface water, except in very shallow wells. Ground-water temperatures generally increase with depth at a rate of about 1°F for each 50 to 100 feet. The temperature of the ground water in

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152 FLORIDA GEOLOGICAL SURVEY Alachua, Bradford, Clay, and Union counties averaged about 740F, which is 4 degrees higher than the mean annual air temperature at Gainesville. The ground-water temperature in the shallow aquifer varied with the air temperature and the temperature in the Floridan aquifer remained about constant at a given location and depth. The deepest well where water temperature was measured is 962 feet deep (well 938-221-1). The temperature, which may have been high due to the injection of hot air-conditioning water into the aquifer nearby, was 800F on November 11, 1957. The water temperature in wells 002-203-1, 725 feet deep, and 003-203-1, 774 feet deep, was 700F. WATER USE RELATION OF WATER QUALITY TO WATER USE The suitability of water for specific uses can be determined by comparing the concentrations of constituents in water with the tolerable concentration of each constituent. Table 11 shows TABLE 11. Chemical Quality of Water Tests Commonly1 Made for Purposes Indicated Test A II C D 1. RBcteriological examinations 2. Orranic nitrogen ... .. ... ...... ..... -..... :. Albuminoid nitrogen .... ...... ... ...... 4. Ammonia nitrogen ..5. Nitrate .... . 6. Taste and odor 7. B. O. D . 6. Dissolved oxygen ..... 9. Oxygen consumed . to. Turbidity t1. Manganese 12. Iron ... .. ........ 13. Fluoride 14. Color .... .... 15. pH 1d. Nitrate .. ...... 17. Chloride Is. Carbonate and bicarbonate -.. ..... . 19. Dissolved solids it. Hardness 21. Sulfate 22. Magnesium 2:. Calcium --....... 24. Specific conductance 25. Sodium .. 26. Potassium ...... 27. Silica ...... .. ... ....... 24. Boron A. Tests for determining sanitary quality of potable or polluted waters. B. Tests for determining suitability of water for industrial uses. C. Tests for determlning the suitability of water for agricultural uses. D. Tests for determining geological relations of natural surface and ground waters. aPennaylvania Dept. of Commerce State Planning Board, Chemical Character of Surface Waters in Pennsylvania, W. F. White, Jr.. 1946-40.

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REPORT OF INVESTIGATIONS NO. 35 153 the physical, bacteriological, and chemical properties usually tested for several general uses. The effect of the physical and chemical properties of each constituent varies with its concentration and the concentration of other constituents. The source, or cause, and the effects of each constituent determined during this study are summarized in table 12. If a water does not have the physical and chemical properties desired for a specific use, it may be treated to produce the desired properties. The water to be treated must be tested in order to determine the kind and extent of treatment necessary. DOMESTIC USE AND PUBLIC SUPPLIES Water used in the home should be free from turbidity, unpleasant taste, odor, harmful micro-organisms, color, concentrations of chemicals harmful to health, chemicals harmful to waterconducting and water-containing equipment, and chemicals harmful to everyday household activities involving the use of water. Standards for drinking water quality are frequently quoted throughout the country. In 1914 the U. S. Public Health Service established standards to control quality of water supplied by interstate common carriers for drinking and for use in culinary processes. The most recent revision of the standards was made in 1961. Drinking water supplied by interstate common carriers and public water supplies are often tailored to satisfy the requirements of many water users. Therefore, the standards are more stringent than is usually necessary for domestic and other uses. The U. S. Public Health Service standards are recommended rather than enforced, but the quality of most public supplies and of many domestic supplies meets the requirements. They are not enforced for two reasons: (1) Some areas have no water meeting the requirements without costly treatment-in these areas water exceeding the recommended limits has been used during individuals' entire lifetimes without adverse effects; (2) some constituents have not been studied in sufficient detail to prove conclusively that they are harmful if exceeding the recommended limits. Limits for fluoride, lead, arsenic, selenium, and chromium set by the U. S. Public Health Service are shown below and should not be exceeded because these elements are toxic at greater concentrations. At concentrations up to the limits shown, no toxic effects are to be expected. The presence of fluoride in concentrations

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154 FLORIDA GEOLOGICAL SURVEY TABLE 12. Water-Quality Characteristics and Their Effects Constituent Source and/or solubility Effects Silica (SIO0) Most abundant e!ement in earth's Causes scale in boiler and deposits crust resistant to solution, on turbine blades. Iron (Fe) Very abundant element, readily Stains laundry and porcelain, bad precipitates as hydroxide. taste. Manganese (Mn) Less abundant than iron, present Stains laundry and porcelain, bad in lower concentrations, taste. Calcium (Ca) Dissolved from most rock. especially limestone and dolomite. Causes hardness, forms boiler scale, ------helps maintain good soil structure Mawnesium (Mr) Dissolved from rocks, industrial and permeability. wastes. Su«lium (Na) Injurious to soils and crops, and Dissolved from rocks, industrial certain physiological condition in wastes, man. Potassium (K) Abundant, but not very soluble in Causes foaming in boilers, stimurocks and soils. lates plankton growth. Bicarbonate (HCO,) Abundant and soluble from limeCauses foaming in boilers and emCarbonate (CO ) stone, dolomite, and soils. brittlement of boiler steel. Sulfate (SO,) Sedimentary rocks, mine water. Excess: cathartic, taste. and industrial wastes. Chloriude CI) Rocks, soils, industrial wastes. Unpleasant taste, increases corsewage, brines. sea water. rosiveness. Fluorilc i F) Not very abundant, sparingly soluble. seldom found In industrial Over 1.6 ppm causes mottling of wastes except as spillage, some children's teeth, 0.88 to 1.6 ppm aid sewage. in preventing tooth decay. Nitrate (NO.,) Rocks, soil, sewaRe, industrialdic s p n, waste, normal decomposition. bacHigh indicates pollution, causes teria. methemaglobanemia in infants. ardlnes as a CaCO, Excessive soap consumption, scale in pipes interferes in industrial processes. up to 60 ppm-soft 60 to 120 ppm-moderately hard 120 to 200 ppm-hard over 200 ppm-very hard up to 1.5 ppm is beneficial; there is no known benefit from the other four metals. Concentrations in excess of the following ,limits constitute a basis for rejection of water for domestic or public consumption: ppm Fluoride 1.7 Lead .05 Arsenic .05 Selenium .01 Chromium, hexavalent .05

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REPORT OF INVESTIGATIONS NO. 35 155 Of the substances listed above, only fluoride was determined in a large number (500) of samples. Significant concentrations of arsenic, selenium, and chromium were not expected and, therefore, were not determined. "Total heavy metals" were determined in about 70 samples from about 35 test wells, drilled during the study period. "Total heavy metals" were due mostly to the presence of zinc. Suggested upper limits of concentration for the following constituents are less restrictive than those for the foregoing elements: ppm Copper 1.0 Iron .3 Manganese .05 Nitrate' 45 Magnesium 125 Zinc 5.0 Chloride 250 Sulfate 250 Phenolic compounds (as phenol) .001 Total dissolved solids (good quality) 500 'Effects of nitrate in water were reported by Comley, 1945; and later by Waring, 1949; Bash, 1950; Maxcy, 1950. Through these studies the limits of concentration were established. Except for color, iron, hardness, and, occasionally, nitrate, the observed concentrations were within the limits shown above. The tests that were made relate only to the chemical and physical suitability of water in the area; they are in no way related to the sanitary condition of the water. AGRICULTURAL USE Agricultural uses include water consumed by livestock, the irrigation of crops, and operation of machinery. Water for consumption by stock is subject to the same limitations as those applicable to water for consumption by people. However, water of poorer quality is satisfactory for most animals.

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156 FLORIDA GEOLOGICAL SURVEY Water-quality standards for stock water supplies are relatively few. The Department of Agriculture of western Australia (1950) published the following limits for dissolved solids concentration in water for stock: Type of stock Dissolved solids (ppm) Poultry 2,860 Pigs 4,290 Horses 6,435 Cattle (dairy) 7,150 Cattle (beef) 10,000 Adult sheep 12,900 According to other investigators, concentrations up to 15,000 ppm are safe for limited periods; but probably, for best growth and development of the animals, water quality with concentration of dissolved solids less than the recommended upper limits is desirable. Observed maximum concentration of substances dissolved in waters in this area was usually less than 500 ppm. Toxic limits of fluoride for some animals have been recommended by various authorities. The Florida State Board of Health reported the following limits (1953). Fluoride (ppm) Reported effects Livestock drinking water 1.0 Harmless to cattle Do 4.0 Hogs, etc.-severe mottling of teeth Do 6.016 Cows-mottled teeth Do 18 Cows-slowly increasing fluorosis Do 55 Cows-disliked water Do 200 Rabbits-lethal Fish 100 Goldfish-survived over 4 days Do 504 Daphnia magna toxicity threshold

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REPORT OF INVESTIGATIONS NO. 35 157 Ground water contained the highest concentration of fluoride but it was less than 2.0 ppm in most samples. In evaluating the usefulness of water for irrigation, the chemical quality is important. Factors to be considered are total concentration of dissolved matter, concentrations of individual constituents, and the relative proportions of some constituents. Many investigators have studied quality criteria for irrigation water. Analyses made during this survey show that the water in the area is good for irrigation. INDUSTRIAL USE The quality requirements for industrial water supplies range widely, and almost every industrial application had different standards. For some uses, such as single-pass condensing or cooling, or for the concentrating of ores, chemical quality is not particularly critical and almost any water may be used. At the opposite extreme, the manufacture of high-grade paper and pharmaceuticals requires water of very high quality. Modern maximum-pressure steam boilers may require makeup water that contains less dissolved matter than the average distilled water of commerce. It is technically possible to treat any water to make it satisfactory for any special use; however, extensive treatment may not be economical. Moore (1941) gives quality tolerance for boiler feed water and water for certain industrial uses (tables 13, 14). The California State Water Pollution Control Board (1952) also reported quality tolerance for industrial water. Temperature of water and its fluctuation with season are important if the water is used for cooling. Ground water is desirable for cooling because of its relatively constant temperature. Industries use a large part of the total water used in the United States today. However, much of the industrial use is nonconsumptive; that is, the water is not evaporated or incorporated into the finished product but is released, possibly with an increased load of dissolved material or possibly with very little difference in composition from the original water. Many industries have resorted to re-use of water that in former years might have been allowed to flow down the sewer or into a surface stream. Recirculation generally concentrates the dissolved material. Eventually, increased recirculation of industrial water will result in a higher average dissolved-solids concentration in industrial effluents, although the volume of such effluents may be reduced.

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TAaB.E 13. Suggested Water-Quality Tolerancess (Allowable limits in parts per million) t Man. Tur. Hiardnet Iron vganse Total Alkalinity Odor Hydrogen Industry or use bidity Color ad CaCO, a M e a Mn iSolids as CaCO, Taste sulfide Other requirementab Air eonditioning ....... '0.6 0.5 ....low I No corrolsveness, slime formation Baking 10 10 .2 2 ..... low .2 P. Brewing: LIgbt beer 10 ..1 .1 500 75 low .2 P. NaCI less than 275 ppm (pH k 6.5-7.0) Dark beer 10 ..... .1 .1 1,000 150 low .2 P. NaCI less than 275 ppm (pH C 7.0 or more). Canning: Leumaes 10 .... 25-75 r .2 .2 --...low I P. General 10 ..2 .2 ..-low I P. Carbonated beverages 2 10 250 .2 .2 850 50-100 low .2 P. Organic color plus oxygen conI b .3 sumed less than 10 ppm. Confectionery -.2 .2 100 .low .2 P. H above 7.0 for hard candy. Cooli en0 .0 .5 .5 ---No corroaiveness, slime formation. Food: General 10 .2 .2 low P. nderin 5 5 -. .2 .2 -low -P. SiO, less than 10 ppm. p Launderin ..-56 .2 .2 -_ Plastica.s, clear uncolored 2 2 -.02 .02 200 Paper and pulp: i; Croundwood 50 20 180 .1.0 .5 -No grit. corrc~lvent". Kraft pulp 25 15 100 .2 .1 300.. Soda and ulfte 15 10 100 *.1 .05 200 _-_ High-frade fight papers 5 5 50 e.1 .05 200 Rayon (viscose): . Pulp production 5 5 8 * .05 .03 100 total 50: ; Al,0, less than 8 ppm, Si0 less hydroxide 8 than 25 ppm, Cu less than 5 ppm. Manufacture .3 -55 .0 .0 --pH 7.8 to 8.3. Tanning 20 10-100 50-135 * .2 .2 total 135: hydroxide 8 Textiles: General 5 20 -.25 .25 . Dyeing 5 5-20 -.25 200 --Constant composition. Residual Wool eouring -. 70 1 10 .... -alumina less than 0.5 ppm. Cotton bandage 5 ..2 .2 plow aMoore, E. W., Progress report of the committee on quality tolerances of water for industrial uses: Jour. New England Water Works Assoc., voL 54, p. 271, 1940. bP Indicates that potable water, conforming to U.S.P.H.S. standards, is necessary. elimit given applies to both Iron alone and the sum of iron and manganese.

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REPORT OF INVESTIGATIONS NO. 35 159 TABLE 14. Suggested Water-Quality Tolerance For Boiler Feed Water' (Allowable limits in parts per million) Pressure (pal) 0-160 150-250 250-400 Over 400 Turbidity ... .... ... ......... .... 20 10 5 1 Color ........... 80 40 5 2 Oxygen consumed .......... ....; ..15 10 4 3 Dissolved oxy en ........... ................... 1.4 .14 .0 .0 Hydrogen sulfide (H,1 ) -..-......-........ :; 3 0 0 Total hardness as CaCO, --....-..-... ........... 80 40 10 2 Sulfate-carbonnto ratio (A.S.M.E.) (N ,804,: Na2CO,) ........ ...... .2...... :1 2:1 3:1 3:1 Aluminum oxide (Alg0,) .......... .... 5 .5 .05 .01 Silica (SI1 ,) ............ ..... .......... .. ..... 40 20 5 1 Blcarbonate (HCO,)2 .. .. .......... .50 o30 5 0 Carbonate (CO ).................................... 200 100 40 20 Hydroxide (OH1) ..50 40 30 15 Total solids4 ..... .. 3,000-G00 2.500-500 1.500-100 50 pH value (minimum) 8........0 8.4 9.0 9.6 IMoore, E. W.. Progress report of the committee on quality tolerances of water for Industrial uses: Jour. New England Water Works Assoc., v. 54, p. 206. 1040. 2Limits applicable only to feed water entering boiler, not to original water supply. :iExcept when odor in live steam would be objectionable. 4Depends on desaln of boiler. In highly developed industrial areas, water-quality problems and waste-disposal problems can be expected to increase in complexity and severity as a result of the closer approach to maximum utilization of water. Neither water problems nor waste disposal problems of a severe nature have been experienced in this area. However, waste material discharged into North Fork Black Creek alters water quality downstream from Boggy Branch. Wastes also affect the quality of small streams. SURFACE WATER Only a small part of the area's surface waters is being used. Recreation, navigation, irrigation, and commercial fishing are the main uses at present (1961). Except for irrigation, for which only a small amount of surface water is being used, all these uses are nonconsumptive. Small quantities of water for irrigation are taken from some lakes and from the Santa Fe River. The full potential of the surface waters is far from being realized. Recreation is by far the greatest use. All lakes in the area are suitable for one or more of the following uses; fishing, swimming, boating, and allied recreational activities. The lakes and streams abound with several varieties of fish. Fish camps offer facilities for sport fishing along the St. Johns River, Orange

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160 FLORIDA GEOLOGICAL SURVEY Lake, Lochloosa Lake, Newnans Lake, Santa Fe Lake, and several of the other larger lakes. Subdivisions are being developed on many lakes, offering lakefront home sites. The St. Johns River is used for navigation, commercial fishing, pleasure boating, and sport fishing. A channel depth of 12 feet is maintained as far upstream as Lake Monroe at Sanford, 160 miles above the mouth. The river at Green Cove Springs, 50 miles above the mouth, harbors a Navy base. GROUND WATER Ground water, one of the most valuable natural resources of Alachua, Bradford, Clay, and Union counties, differs from most other natural resources in that ground water is a renewable resource. In fact, hundreds of millions of gallons of water recharge the FIoridan aquifer in these counties each day. Almost all rural homes, industries, and municipalities depend on ground water for their water supply. Ground water is widely used for two reasons. First, the chemical character and temperature are usually constant, and second, ground water is readily accessible. Moreover, in large areas in Clay County, the water is delivered to the user under pressure so that he is spared the expense of pumping it. Many of the smaller supplies of water are taken from the upper aquifers; whereas, the larger supplies are taken from the Floridan aquifer. Probably, less water is taken from the watertable aquifer than from any other aquifer. The water-table aquifer supplies water to only a few dug wells and wells with sand points. Many domestic supplies are withdrawn from wells tapping secondary artesian aquifers; in fact, more than half of the wells in the four counties probably tap secondary artesian aquifers. All the larger users of water, however, draw their supplies from the Floridan aquifer. These users include municipalities, irrigators, and industries. It is estimated that in 1960 about 4,000 million gallons of ground water were used in Alachua County, about 2,300 million gallons in Bradford County, about 3,800 million gallons in Clay County, and about 230 million gallons in Union County. Figure 92 shows the centers of heavy pumping and the estimated use of ground water in 1960. Despite the wide use of ground water, it is a relatively undeveloped resource in these counties. Hundreds of millions of

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-...... .-,.,, .,, ..... ...T y. *IEg e .C OK( -y ""S.n " -' -%V V. k .i l-l tr sr p a e e r Ii t "W> 49 _-1 Les m. .; .4 "s P?,AU Cglla? centers of concentrated pumping and estimated use of ground water in 1960. (7)e Islpn lRIC Ilad !Ig Lld'uwu. Vl~s D'2Ln gwp nnllnrI1* n le 1 ,iZ centers of concentrated pumping and estimated use of ground water in 1960.

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162 FLORIDA GEOLOGICAL SURVEY gallons a year of additional water can be developed from the Floridan aquifer at almost any place in the four counties if the development is based on sound scientific principles and adequate hydrologic data. SUMMARY The oldest formation penetrated by water wells in the area is the Lake City Limestone of Eocene age. The Lake City and the overlying Avon Park Limestone of Eocene age lie at relatively great depths in subsurface. The uppermost Eocene unit, the Ocala Group is exposed in southern and western Alachua County. The Ocala Group is overlain by relatively thick and impervious deposits of Miocene age. The Miocene deposits, composed mostly of clay and sandy clay, confine water in formations of Eocene age under artesian pressure in most of the four-county area. The most extensive confining bed is the Hawthorn Formation of Miocene age which has a maximum thickness of about 250 feet. Deposits of sand and clayey sand that compose the unnamed coarse clastics of Pleistocene age overlie the Miocene deposits in southwestern Clay and southeastern Bradford Counties. In other parts of the four counties several higher terraces of Pleistocene age that are the older Pleistocene and Recent deposits are over the Miocene. The older Pleistocene terrace deposits, which are as much as 140 feet thick, have wide surface distribution in the four counties, and the Pleistocene and Recent deposits, which generally are 60 feet or less in thickness, cover older formations in Clay County. The crest of a major structure, the Ocala uplift, transverses southwestern Alachua County. The formations dip away from the Ocala uplift to the east-northeast and have a regional average dip of about 6 feet per mile. The average streamflow from the four counties is approximately 1,150 mgd, which comes from four river basins; Black Creek, Santa Fe River, Orange Creek, and Etonia Creek. In addition to these, the St. Johns River borders Clay County on the east and has an estimated average flow at Green Cove Springs of about 4,500 mgd. An area of about 300 square miles in southwestern Alachua County has no surface outflow. Rairfall on that area seeps directly into the ground or is collected in sinkholes. The average runoff from the four counties is about 12 inches per year, or about one-fourth the average rainfall.

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REPORT OF INVESTIGATIONS NO. 35 163 Average flow from the Black Creek basin in Clay County is 515 cfs (330 mgd). The South Fork Black Creek contributes 225 cfs, the North Fork Black Creek contributes 200 cfs, and small tributaries below the confluence of the two forks contribute 90 cfs. Average runoff from the basin is 14.8 inches per year. However, runoff varies from area to area within the basin. The average runoff from the South Fork is about 16.0 inches per year and from the North Fork, about 13.7 inches per year. The Santa Fe River has a drainage area of 1,440 square miles. Included in this area are Bradford County, Union County, and the northern part of Alachua County. The average flow from the basin is about 2,400 cfs (1,550 mgd). The river disappears into a sinkhole at O'leno State Park, 5 miles north of High Springs. Above this point, the drainage area is about 800 square miles and the average flow from the area is 650 cfs. Average runoff from the basin is about 22 inches per year. However, average runoff from areas within the basin varies from 6 to 85 inches per year. Runoff from the basin above O'leno State Park is about 11 inches per year, and average runoff from the area below O'leno State Park is about 27 inches per year. The area of 130 square miles between the High Springs and Fort White gaging stations has an average runoff of 85 inches per year, or over 11/. times the average rainfall. The high base flow in the lower basin comes from springs and ground-water inflow. The average flow from the Orange Creek basin is about 230 cfs (150 mgd). Within this basin are three large lakes that cover 44 square miles: Orange Lake, 25.7 square miles; Lochloosa Lake, 10.3 square miles; and Newnans Lake, 8.2 square miles. Much of the streamflow in the upper two-thirds of the basin is relegated to storage within these lakes. Average runoff from the basin is about 5 inches per year. Runoff from the Etonia Creek basin is extremely low, probably less than 5 inches per year from the entire basin. Even though the runoff is low, the area has much to offer in the way of water resources. The upper 150 square miles of the basin, in southwestern Clay County and northwestern Putnam, contains some 100 lakes. Most of these lakes are perennial although the stages of some vary considerably from dry seasons to wet seasons. These lakes, which have elevations from about 80 feet to 174 feet above sea level, are situated in a group of sandhills. The upper aquifers, which are above the Floridan aquifer, are present everywhere in the four counties except in southern and

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164 FLORIDA GEOLOGICAL SURVEY western Alachua County. The upper aquifers are composed of a water-table aquifer and several secondary artesian aquifers. The water-table aquifer consists of shallow sand or clayey sand of Miocene, Pliocene, Pleistocene, or Recent age that contain water, except locally, under water-table conditions. The water-table aquifer in most places will yield sufficient water for domestic purposes from shallow dug or sand-point wells. The secondary artesian aquifers, which are sandwiched between the water-table aquifer and the Floridan aquifer, consist of limestone layers and sand layers of the Hawthorn Formation, limestone layers of the Choctawhatchee Formation, and perhaps shell beds in eastern Clay County of Pleistocene and Recent age. The piezometric surfaces of the secondary artesian aquifers lie between the water table of the water-table aquifer and the piezometric surface of the Floridan aquifer. Probably more wells in the four counties draw water from a secondary artesian aquifer than draw water from the water-table aquifer or the Floridan aquifer. The secondary artesian aquifers will produce enough water for domestic use and other small supplies. The Floridan aquifer consists of several hundred feet of interbedded soft porous limestone and hard dense limestone and dolomite of Eocene age, Oligocene age, and Miocene age that, as far as is known, act as a hydrologic unit. The Floridan aquifer, as a whole, probably has a high permeability in a lateral direction and a low permeability in a vertical direction. Water in the Floridan aquifer is under artesian conditions east of a line running through Gainesville in a southeast-northwest direction, and under watertable conditions west of this line. Water recharges the Floridan aquifer by leaking through the confining beds, by percolating through breaches in the confining beds, and by direct percolation into the aquifer where no confining bed exists. At least 45 mgd of water recharge the Floridan aquifer in a 525-square mile area in the vicinity of Keystone Heights. At least one-half mgd of water percolate to the Floridan aquifer in a 300 square mile area in southern and western Alachua County where the Floridan aquifer is at or near the surface. The specific capacities of 5 wells tapping the Floridan aquifer in western Alachua County ranged from 29 to 20,000 gpm per foot of drawdown; the specific capacities of 18 wells in central and eastern Alachua County ranged from 2 to 700 gpm per foot of drawdown. The specific capacities of 7 wells tapping the Floridan aquifer in Bradford County ranged from 25 to 210 gpm per foot of drawdown and averaged 78. The specific capacities of 21 wells

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REPORT OF INVESTIGATIONS NO. 35 165 tapping the Floridan aquifer in eastern and northern Clay County ranged from 2 to 60 gpm per foot of drawdown and averaged about 12; the specific capacities of 12 wells in western Clay County ranged from 22 to 300 gpm per foot of drawdown and averaged about 120. The specific capacities of 7 wells in Union County ranged from 60 to 360 and averaged 145 gpm per foot of drawdown. From June 1934 to June 1960 the piezometric surface of the Floridan aquifer declined about 18 feet at Orange Park and about 14 feet near Green Cove Springs. Hundreds of millions of gallons of additional water a year can probably be developed from the Floridan aquifer at almost any place in the four counties if the development is based on sound scientific principles and adequate hydrologic data. Except for the Etonia Creek basin in southwestern Clay County, the surface waters in the area are persistently colored and often contain iron in excess of 0.30 ppm. The surface waters are generally soft and the hardness as calcium carbonate usually is less than 50 ppm. Occasionally, the hardness as calcium carbonate exceeds 100 ppm in New River water near Lake Butler. The hardness as calcium carbonate often exceeds 100 ppm in the Santa Fe River water at High Springs. In contrast to surface waters, ground waters have color intensities of 10 units or less, except in localized areas. In the watertable aquifer, concentrations of iron in excess of 0.30 ppm were observed in about 38 percent of the samples. Iron in excess of 0.30 ppm was observed in about 16 percent of the samples from the secondary artesian aquifer and in about 10 percent of the samples from the Floridan aquifer. Hardness as calcium carbonate is typically the dominant characteristic in ground water, except where the water-table aquifer is chiefly sand. As a rule, the concentration of substances dissolved in streams is much less than the concentration of substances dissolved in ground water, except for water in the sand aquifers of the watertable aquifer. The concentration of substances dissolved in ground waters seldom exceeded 500 ppm and usually was less than 300 ppm. The range of concentration values for streams and ground water overlap. The concentration ranges for streams and aquifers overlap because the water in streams and aquifers are mixtures in varying proportions of rainwater, direct runoff water from the surface, and water from aquifers.

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166 FLORIDA GEOLOGICAL SURVEY REFERENCES Black, A. P. 1951 (and Brown, Eugene) Chemical character of Florida's waters1951: Florida State Board Cons., Div. Water Survey and Research Paper 6. Brown, Eugene (see Black, A. P.; Cooper, H. H.) Cagle, J. W., Jr. (see Clark, W. E.) California State Water Pollution Control Board 1952 Water quality criteria: California State Water Pollution Control Board pub. 3. 1954 Report on the investigation of travel of pollution: California State Water Pollution Control Board pub. 11. Christiansen, J. E. (see Magistad, O. C.) Clark, W. E. 1963 (Musgrove, R. H., Menke, C. G., and Cagle, J. W., Jr.) Hydrology of Brooklyn Lake near Keystone Heights, Florida: Florida Geol. Survey Rept. Inv. 33. Colby, B. R. (see Gatewood, J. S.) Cooke, C. W. 1929 (and Mossom, Stuart) Geology of Florida: Florida Geol. Survey 20th Ann. Rept., p. 29-227. 1945 Geology of Florida: Florida Geol. Survey Bull. 29. Cooper, H. H., Jr. 1953 (and Kenner, W. E., and Brown, Eugene) Ground water in central and northern Florida: Florida Geol. Survey Rept. Inv. 10. Crooks, J. W. (see Pride, R. W.) Cropper, W. H. (see Hem, J. D.) Eaton, F. M. 1935 Boron in soils and irrigation waters and its effect on plants: U. S. Dept. Agr. Tech. Bull. 448, p. 1-133. 1942 Toxicity and accumulation of chloride and sulfate salts in plants Jour. Agr. Research 64, p. 357-399. 1950 Significance of carbonates in irrigation water: Soil Sci., v. 69, p. 123-133. Ferguson, G. E. (also see Parker, G. G.) 1947 (and Lingham, C. W., Love S. K., and Vernon, R. 0.) Springs of Florida: Florida Geol. Survey Bull. 31.

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REPORT OF INVESTIGATIONS NO. 35 167 Florida State Board of Health 1953 Peace and Alafia Rivers, stream sanitation studies, 1950-53, v. 1, The Alafia River: Jacksonville, Fla. 1960 Some physical and chemical characteristics of selected Florida waters: Jacksonville, Fla., Bur. of Sanitary Eng., Div. Water Supply. Foster, J. B. 1961 Well design as a factor contributing to water losses from the Floridan aquifer-eastern Clay County, Florida: Florida Geol. Survey Inf. Circ. 35. Gatewood, J. S. 1950 (Robinson, T. W., Colby, B. R., Hem, J. D., and Halpenny, L. C.) Use of water by bottom-land vegetation in Lower Safford Valley, Arizona: U. S. Geol. Survey Water-Supply Paper 1103. Gunter, Herman (see Sellards, E. H.) Halpenny, L. C. (see Gatewood, J. S.) Headley, F. B. (see Scofield, C. S.) Hem, J. S. (also see Gatewood, J. S.) 1959 Study of interpretation of the chemical characteristics of natural water: U. S. Geol. Survey Water-Supply Paper 1473. 1959 (and Cropper, W. H.) Survey of ferrous-ferric chemical equilibria and redox potentials: U. S. Geol. Survey Water-Supply Paper 1459-A. 1960 (and Skougstad, M. W.) Co-precipitation effects in solutions containing ferrous, ferric and cupric ions: U. S. Geol. Survey Water-Supply Paper 1459-E. 1960 Restraints on dissolved ferrous iron imposed by bicarbonate, redox potential, and pH: U. S. Geol. Survey Water-Supply Paper 1459-B. 1960 Some chemical relationships among sulfur species and dissolved ferrous iron: U. S. Geol. Survey Water-Supply Paper 1459-C. 1960 Complexes of ferrous iron with tannic acid: U. S. Geol. Survey Water-Supply Paper 1459-D. Kenner, W. E. (see Cooper, H. H.) Kohler, M. A. 1954 Lake and pan evaporation, in Water-loss investigations: Lake Hefner studies, technical report: U. S. Geol. Survey Prof. Paper 269, p. 127-148. Langbein, W. B. (see Leopold, L. B.) Lingham, C. W. (see Ferguson, G. E.) Leopold, L. B. 1960 (and Langbein, W. B.) A primer on water: U. S. Dept of Interior.

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168 FLORIDA GEOLOGICAL SURVEY Love, S. K. (see Ferguson, G. E.; Parker, G. G.) Masictad, 0. C. 1944 (and Christiansen, J. E.) Saline soils, their nature and management: U. S. Dept. Agr. Circ. 707, p. 8-9. Mather, J. R. (see Thornthwaite, C. W.) Matson, G. E. 1913 (and Sanford, Samuel) Geology and ground water of Florida: U. S. Geol. Survey Water-Supply Paper 319. Menke, C. G. (see Clark, W. E.) Mossom, Stuart (see Cooke, C. W.) Musgrove, R. H. (see Clark, W. E.) Oborn, E. T. 1960a A survey of pertinent biochemical literature: U. S. Geol. Survey Water-Supply Paper 1469-F. 1960b Iron content of selected water and land plants: U. S. Geol. Survey Water-Supply Paper 1459-G. Parker, G. G. 1955 (Ferguson, G. E., Love, S. K. and others) Water resources of southeastern Florida, with special reference to the geology and ground water of the Miami area: U. S. Geol. Survey WaterSupply Paper 1255. Pirkle, E. C. 1956 Notes on physiographic features of Alachua County, Florida: Quart. Jour. Florida Acad. Sci., v. 19, no. 2-3, p. 168-182. 1956 The Hawthorn and Alachua formations of Alachua County, Florida: Quart. Jour. Florida Acad. Sci., v. 19, no. 4, p. 197-240. Pride, R. W. 1958 Floods in Florida magnitude and frequency: U. S. Geol. Survey open-file report. 1961 (and Crooks, J. W.) Drought of 1954-56-Its effect on Florida's surface-water resources: Florida Geol. Survey Rept. Inv. 26. President's Water Resources Policy Commission 1950 A water policy for the American people: General Rept., v. 1, p. 152-153. Puri, H. S. 1957 Stratigraphy and zonation of the Ocala Group: Florida Geol. Survey Bull. 38. 1959 (and Vernon, R. 0.) Summary of the geology of Florida and a guidebook to the classic exposures: Florida Geol. Survey Spec. Pub. no. 5. Robinson, T. W. (see Gatewood, J. S.)

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REPORT OF INVESTIGATIONS No. 35 169 Rainwater, F. H. 1960 (and Thatcher, L. L.) Methods for collection and analysis of water samples: U. S. Geol. Survey Water-Supply Paper 1454. Sanford, Samuel (see Matson, G. E.) Scofield, C. S. 1921 (and Headley, F. B.) Quality of irrigation water in relation to reclamation: Jour. Agr. Research 21, p. 265-278. 1936 The salinity of irrigation water: Smithsonian Inst. Ann. Rept., 1935, p. 275-287. 1949 Trends of irrigation development in the United States: Symposium Am. Chem. Soc., p. 1-11 (mimeographed). Sellards, E. H. 1913 (and Gunter, Herman) The artesian water supply of eastern and -. southern Florida: Florida Geol. Survey 5th Ann. Rept., p. 103-290. Skougstad, M. W. (see Hem, J. D.) Stringfield, V. T. 1936 Artesian water in the Florida Peninsula: U. S. Geol. Survey Water-Supply Paper 773-C. Thatcher, L. L. (see Rainwater, F. H.) Theis, C. V. 1935 The relation between the lowering of the piezometric surface and the rate and duration of discharge of a well using groundwater storage: Am. Geophys. Union Trans., v. 16, p. 519-524. Thorne, D. W. (see Thorne, J. P.) Thorne, J. P. 1951 (and Thorne, D. W.) Irrigation waters of Utah: Utah Agr. Expt. Sta. Bull. 349. Thornthwaite, C. W. 1955 (and Mather, J. R.) The water balance: Publications in climatology, v. 8, no. 1, Drexel Institute of Technology, Cunterton, New Jersey. * U. S. Department of Agriculture 1955 Water, the 1955 yearbook of agriculture: Washington, U. S. Govt. Printing Office, 731 p. 1957 Soil, the 1957 yearbook of agriculture: Washington, U. S. Govt. Printing Office, 784 p. U. S. Geological Survey 1954 Quality of water for irrigation, Western United States: U. S. Geol. Survey Water-Supply Paper 1264.

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170 FLORIDA GEOLOGICAL SURVEY U. S. Salinity Laboratory Staff 1954 Diagnosis and improvement of saline and alkali soils: U. S. Dept. Agr. Handbook 60. Vernon, R. O. (also see Ferguson, G. E.; Puri, H. S.) 1951 Geology of Citrus and Levy Counties, Florida: Florida Geol. Survey Bull. 88. Wenzel, L. K. 1942 Methods for determining permeability of water-bearing materials: U. S. Geol. Survey Water-Supply Paper 887. White, W. A. 1958 Some geomorphic features of central peninsular Florida: Florida Geol. Survey Bull. 41. White, W. F. 1946 Chemical character of surface water in Pennsylvania; 1946: Pennsylvania Dept. of Com., State Planning Board. 1949 Chemical character of surface water in Pennsylvania; 1949: Pennsylvania Dept. of Com., State Planning Board. Wilcox, L. V. 1948 The quality of water for irrigation use: U. S. Dept. of Agr. Tech. Bull. 962, p. 1-40.