state of florida state board of division of geology...

STATE OF FLORIDASTATE BOARD OF CONSERVATION

DIVISION OF GEOLOGY

FLORIDA GEOLOGICAL SURVEYRobert 0. Vernon, Director

INFORMATION CIRCULAR NO. 41

INTERIM REPORT ON THE WATER RESOURCES

OFORANGE COUNTY, FLORIDA

ByWilliam F. Lichtler, Warren Anderson, and Boyd F. Joyner

U. S. Geological Survey

Prepared by the

UNITED STATES GEOLOGICAL SURVEY

in cooperation with the

BOARD OF COUNTY COMMISSIONERS OF ORANGE COUNTYand the

FLORIDA GEOLOGICAL SURVEY

TALLAHASSEE

1964

4oo4

AGRfICULTURALLIBRARY

Completed manuscript received

February 15, 1963

Printed by the Florida Geological Survey

Tallahassee

ir

CONTENTS

PageAbstract . . . . . . . . . . . . . . ... . ... . . . . . . . . . . ........... 1Introduction .. ............... ................... . 3

Purpose and scope of investigation .. . . . . . . ....... ....... 3Acknowledgments ................... .............. . ..... 4Previous investigations . . . . . . . . . . . . . . ... .. . . . . . . . ....... 4Well-numbering system . . . . . . . . . . . . . . . .. ... ... . ... ..... 5

Description of the area . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . 5Climate . ...... . . . . . . . . . . .. . . . . . . . ... .. . . . . .. . 8Sinkholes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Drainage . . . . . . . . . . . . . . . . . . .. .. . . . . . . . . . . . . ...... 10Geology. ...... . . .. . . .. . . .... .. . . . ..... 12

Hydrology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Surface water . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . ..... . . . 15

Kissimmee River basin . . . ..... .. .. ...... .... .. . 15Reedy Creek . . . . . .. . . . . . . . . .. . . . . . . . . . . . . . 15Bonnet Creek . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Shingle Creek .. . . . ......... ... .. . . . . . .... 19

Boggy Creek.. . ...... . . . . ... . . . . . . . . . . ... 20Jim Branch ........ . . . . . ... .. . . .. . . .. . . . 20Ajay-East Tohopekaliga Canal.... ... .. . .. . ... ... 21

St. Johns River basin . . . . . . . . . . . . . . . . . . . . . . . . . . .. . 21

St. Johns River . . . . . . . . . . . . . . . . . 21

Small tributaries draining to east ...... . . . . . . ........ . . 24

Lake Pickett . . . . . . . . . . . . . . . . . . . . . . . . . . ... . 25Econlockhatchee River . . . . .. . .. . . . . . .. . . . .... .. . 25Little Econlockhatchee River . .. . . . . . .. . . . . . ....... . 27

Howell Creek ............ ............ . . . . . 27

Wekiva River . . . . . ..... .. . . . . . .. . . . . . . .... ..28

Apopka-Beauclair Canal . . . . . . . . . . . . . . . . . . . . . . 29Lakes, swamps, and marshes . . . . . . . . . . . . . . . . . . . . . ... 30

Ground water . ..................... ...... . ...... .. .31

Nonartesian aquifer . . . . . . . . . . . . . . . . ... . .. . . .. 31

Aquifer properties. . . . . . . . . ... . . . . . . .. . . . . . . 31

Water levels . . . ................. ... . . . . . . . . . . . 32Recharge and discharge . ......... . . ....... . . 33

Quality of water .. . . . .. .. . . . .. . . .. . . . . . . . .. 33

Shallow artesian aquifers . . . . . . . . . . . . . . . . . . . . 35

Aquifer properties. .. .................... . . . 35Water levels . . . . . . . . . . . . . . . . . . . .. . . . . . . . 35

S Recharge and discharge .. . . .. . . . . . . .. . . . 35

iii

Floridan aquifer...... ........... ..... . 35

Aquifer properties . . . *... .. .... .. . . .... .. . 36 .

Piezometric surface .. . . .................... . . . . : 36

Recharge and discharge ................... .... . 39

Quality of water. ......... ............. . ... 39Pumping test . ............... ................. . 41

Water budget ............. . ........ . .............. . . . 44

Use of water ... . ........ ..... .. . . ... .. ............ . 44

References ................ ........... ......... . 47

ILLUSTRATIONS

Figure

1 Florida showing location of Orange County ....... .. .. . . .. 6

2 Physiographic regions of Orange County, Florida .. . . -..... . . . 7

3 Distribution of drainage wells in Orange County, Florida ... .. . 11

4 List and duration of records at surface-water gaging stations inor near Orange County, Florida . . . . . . . . . . . . . . ..... . . . . 16

5 Drainage basins and surface-water data collection points in

Orange County, Florida .................. ........ 17

6 Relation of specific conductance to stream flow, St. Johns River

at station 36, near Cocoa, Florida, 1958-61 . . . . . . . . . . ..... . 237 Cumulative frequency curves of specific conductance for the

Econlockhatchee River at station 18, near Bithlo, Florida, 1960-61 268 Hydrographs of observation wells in Orange County and rainfall at

Orlando, Florida ....... . . ........... .. ......... 329 Orange County, Florida, showing location of inventoried wells

other than drainage wells .......................... . 3410 Orange County, Florida, showing the contours of the piezometric

surface at high water conditions, September 1960 ..... .. . . 3711 Orange County, Florida, showing the contours of the piezometric

surface at about normal conditions, July 1961 . . . . . . . . . . .. 3812 Orange County, Florida, showing general range of dissolved

solids of the water in wells in the Floridan aquifer . . . . . . . ... 4013 Composition of mineral content of water from selected wells in

the Floridan aquifer in Orange County, Florida . . . . . . .... .. .. 42

Table

I Temperature and rainfall at Orlando, Florida . . . . . . . . . . .. 9

2 Summary of the properties of the geologic formations penetratedby water wells in Orange County, Florida ..... .. .. ...... . . . 13

3 Sites where miscellaneous surface-water data have beencollected in and near Orange County, Florida .. . ...... . .18

iv

4 Data on small tributaries draining the eastern part of Orange

County, Florida .................. ............. .. 24

5 Discharge measurements of springs in Orange County, Florida... 29

6 Results of pumping well 831-122-4, Orlando, Florida, February 17,

1961 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . 43

-- y

INTERIM REPORT ON THE WATER RESOURCES

OF

ORANGE COUNTY, FLORIDA

By

William F. Lichtler, Warren Anderson, and Boyd F. Joyner

ABSTRACT

The population and industry of Orange County are expanding

rapidly but the demand for water is expanding even more rapidly. This

progress report on the first half of a 6-year investigation provides in-

formation for use in the development and management of the water

resources of the area.

The county lies in three physiographic regions: (1) Eastern

Lowlands, (2) Parallel Ridges, and (3) Rolling Highlands. The Rolling

Highlands, also known as the Orlando Ridge, are characterized by

numerbus sinkhole lakes and depressions.

Surface runoff forms the principal drainagein the Eastern Lowlands

and Parallel Ridges, whereas underground drainage prevails in the

Rolling Highlands.

Surface water is temporarily stored in lakes, swamps, and streams.

Lakes are the most reliable sources of surface water as the swamps and

most of the streams, except the St. Johns, Wekiva, and Little Econlock-

hatchee rivers, go dry or nearly dry during droughts.

Approximately 90 of the 1,000 square miles in Orange County are

covered by water. The southwestern 340 square miles of the county

drain to the south by the Kissimmee River system. The eastern and

northern 660 square miles of the county drain to the north by the St. Johns

River.

1

2 FLORIDA GEOLOGICAL SURVEY

The water in the lakes and streams in Orange County generally issoft, low in mineral content, and high in color. The quality of the water;n most of the lakes remains fairly constant.

Ground water is obtained from: (1) a nonartesian aquifer composedof c!astic material of late Miocene to Recent age; (2)several discon-tinuous shallow artesian aquifers in the Hawthorn Formation of middleMiocene age; and (3) the Floridan aquifer composed of the Ocala Group,the Avon Park Limestone, and the Lake City Limestone, all of Eoceneage.

The surficial nonartesian aquifer produces relatively small quanti-ties of soft water that is sometimes high in color. The shallow artesianaquifers produce moderate quantities of generally moderately hard tohard water.

The Floridan aquifer is the principal source of ground water inOrange County. It comprises more than 1,300 feet of porous limestoneand dolomite and underlies sand and clay deposits that range in thick-ness from about 40 feet to more than 350 feet. Wells in the Floridancquifer can yield more than 4,000 gpm (gallons per minute).

Artesian heads in the Floridan aquifer range from about 10 feetabove to more than 60 feet below the land surface. The quality of thewater ranges from moderately hard in the western and central parts tosaline in the extreme eastern part of the county.

INFORMATION CIRCULAR NO. 41 3

INTRODUCTION

The rapid increase of population and industry of Orange Countyhas created a rapidly increased demand for water. Not only are theremore people and more uses for water, but also the per-capita use ofwater is increasing. Central Florida is becoming a major center inmissile development and space exploration and the increase in demandfor water is expected to continue and even to accelerate.

PURPOSE AND SCOPE OF INVESTIGATION

The purpose of this investigation is to furnish data that will beuseful in the conservation, development, and management of the waterresources of Orange County. Water is among the most important naturalresources of Florida. Orange County, with more than 50 inches ofannual rainfall, is blessed with an abundant supply. However, thissupply is not evenly distributed throughout the year, or from year toyear, nor are there adequate-storage reservoirs in all parts of the county.

An evaluation of all factors affecting the water resources of anarea is necessary for the protection, efficient development, and manage-ment of water supplies. Recognizing this fact, the Board of CountyCommissioners of Orange County entered into a cooperative agreementwith the U. S. Geological Survey to investigate the water resourcesof Orange County. The investigation is a joint effort by the threebranches of the Water Resources Division of the Survey. The reportwas prepared under the supervision of M. I. Rorabaugh, succeededby C. S. Conover, Tallahassee; A. O. Patterson, Ocala; and K. A.

MacKichan, Ocala.

This interim report summarizes the findings of the first half of

a planned 6-year investigation. The report contains information on

the quantity, quality, and occurrence of surface and ground water in

and near Orange County. The information contained herein will be

incorporated in a final report to be published by the Florida GeologicalSurvey.


ACKNOWLEDGMENTS

The authors express their appreciation to the many residents of

Orange County who gave information about their wells and to various

public officials whose cooperation greatly aided the investigation.

Special appreciation is expressed to Fred Dewitt, county engineer;

to Robert Simons and Jesse Burkett of the city of Orlando water and

sewer department; and to Gene Pou, Ross Snyder, and Russ Mills of

the city of Orlando engineering department for their assistance.

Appreciation is given the well drillers in or near Orange County

who furnished geologic and hydrologic data and permitted collection of

water samples and drill cuttings and measurements of water I.evels

during drilling operations.

Albert Schwartz and other staff members of the U. S. Soil Conserva-

tion Service gave advice and information.

PREVIOUS INVESTIGATIONS

Two previous investigations of the water resources of Orange

County have been made. A report by the U. S. Geological Survey (19.43)

gives the results of a study of lakes as a source of municipal water

supply for Orlando. A detailed investigation by Unklesbay (1944)

deals primarily with drainage and sanitary wells in Orlando and vicinity

and their effect on the ground-water resources of the area.

Other investigators have included Orange County in geologic and

hydrologic studies. Fenneman (1938), Cooke (1939), MacNeil (1950),and White (1958) describe the topographic and geomorphic features ofcentral Florida. Cole (1941, 1945), Cooke (1945), Vernon (1951), andPuri (1953) describe the general geology of central Florida and make

many references to Orange County. Sellards (1908), Sellards and Gunter

(1913), Matson and Sanford (1913), Gunter and Ponton (1931), Parker,Ferguson, Love, and others (1955), Brown, Kenner, and Brown (1957),and Brown (1962) discuss the geology and water resources of Brevard

County. Stringfield (1935, 1936) and Stringfield and Cooper (1950)investigated the artesian water in peninsular Florida, including Orange

County. Collins and Howard (1928), Black and Brown (1951), Wanderand Reitz (1951), and the Florida State Board of Health (1961) give

information about the chemical quality of water in Orange County.


WELL-NUMBERING SYSTEM

The well-numbering system used in this report is based on latitudeand longitude coordinates derived from a statewide grid of 1-minuteparallels of latitude and meridians of longitude. Wells within thesequadrangles have been assigned numbers consisting of the last digitof the degree and the two digits of the minute of the line of latitudeon the south side of the quadrangle, the last digit of the degree andthe two digits of the minute of the line of longitude on the east sideof the quadrangle, and the numerical order in which the well withinthe quadrangle was inventoried. For example, well 832-122-4 is thefourth well that was inventoried in the 1-minute quadrangle north of28032' north latitude and west of 81022' west longitude. By this systemwells referred to by number in the text can be located on figure 9.

DESCRIPTION OF THE AREA

Orange County is in the east-central part of the Florida Peninsula(fig. 1). It has an area of es-entially 1,000 square miles of whichabout 910 square miles are land and about 90 square miles are water.It is bounded on the east by Brevard County, on the north by Seminoleand Lake counties, on the west by Lake County, and on the south byOsceola County.

The population of Orange County in 1960 was 263,540. In thatyear Orlando, the largest city-in the county, had a population of 88,135,while Winter Park, the second largest city, hdci- populotio.ofof_17,160.

- The principal agricultural crops are citrus, vegetables, and cattle.

In 1960 there were about 67,000 acres of citrus groves, about 6,000acres of vegetables, mostly in the Zellwood muck lands, and about

15,000 head of cattle.

Orange County is in the Atlantic Coastal Plain physiographic

province described by Meinzer (1923, pl. 28). The county is subdividedinto three physiographic regions: the Eastern Lowlands, the Parallel

Ridges, and the Rolling Highlands (fig. 2).

The Eastern Lowlands include the St. Johns River marsh, the

northern part of the Econlockhatchee River basin and the northeastern

part of the county east of Rock Springs. Elevations range from about


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460 kr 0 10 2D 0 omil

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8,145 40' 35' 30' 25' 20' ' ' 05' 81'0' 55' o50'

04 L AK E C O UNTY LXPLANNATION Nabove mean sea level

4d 4' -4-0 fool onlr40S E M I N OL E Ponholovay Ihorlne

SLak RA NApopho 'C 0 U N T Y

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1-0

40 35 30' 25 20 0 05 8100' 55' 80.50

Bose ten from U.S. 2 3 4 5 e6 7 9_9 10 ml e

'-24,000

Figure 2. Physiographic regions of Orange County, FloridaFigure 2. Physiogrophic regions of Orange County, Florida


5 feet above msi (mean sea level) near the St. Johns River to about

35 feet above msi where the lowlands merge with the Parallel Ridges.

The Parallel Ridges occupy most of the middle portion of thecounty between the Eastern Lowlands and the Rolling Highlands.EEevations range from 35 to 105 feet above msl but are mostly between50 and 85 feet above msl. The ridges and intervening lower areasparallel to the Atlantic coast are best developed in the area betweenOrlando and the Econlockhatchee River.

The Rolling Highlands occupy the western part of Orange Countywith an island outlier in the vicinity of Orlando. Elevations rangefrom about 50 feet in the Wekiva River basin to about 210 feet abovemsl near the Avalon lookout tower in the southwestern part of the county.This area contains many lakes and depressions that usually have nosurface outlets.

The three physiographic regions described above are approximatelyequivalent to the Pleistocene terraces postulated by MacNeil (1950) asthe Pamlico terrace from about 8 feet to about 30 feet above msl, theWicomico terrace from about 30 feet to about 100 feet above msl, andthe Okefenokee terrace from about 100 to 150 feet above msl.

Cooke (1939) has called the surface defined by the 42- and 70-foot shorelines the Penholoway terrace and the surface defined bythe 70- and 100-foot shorelines the Wicomico terrace. The altitudesabove 150 feet in Orange County probably represent sandhills or alteredremnants of higher terraces.

CLIMATE

Orange County has a subtropical climate with only two pronouncedseasons - winter and summer. The average annual temperature atOrlando is essentially 72 0 F and the average annual rainfall is 51.4inches. Summer thunderstorms account for most of the rainfall. Thunder-storms occur on an average of 83 days per year (U. S. Weather Bureau,annual report, 1960); one of the highest incidences of thunderstorms inthe United States.


Table 1. Temperature and Rainfall at Orlando, Florida

Normal Normal Normal Normal Maximum Minimumrmaximum minimum average rainfall rainfall rainfalltemp.

2 ('F) temp. ("F) temp. (*F) (inches) (inches) (year) (inches) (year)

Jan. 70.7 50.0 60.4 2.00 6.44 1948 0.15 1950

Feb. 72.0 50.7 61.4 2.42 5.64 1960 .10 1944

Mar. 75.7 54.0 64.9 3.41 10.54 1960 .16 1956

April 80.5 59.8 70.2 3.42 6.18 1953 .28 1961

May 85.9 66.2 76.1 3.57 8.58 1957 .43 1961

June 89.1 71.4 80.3 6.96 11.61 1947 1.97 1948

July 89.9 73.0 81.5 8.00 19.57 1960 4.35 1957

Aug. 90.0 73.5 81.8 6.94 15.19 1953 3.40 1958

Sept. 87.6 72.4 80.0 7.23 15.87 1945 1.65 1958

Oct. 82.6 65.3 74.0 3.96 14.51 1950 1.51 1949

Nov. 75.6 56.2 65.9 1.57 4.86 1951 .09 1950

Dec. 71.6 51.2 61.4 1.89 4.30 1950 trace 1944

Yearly 80.9 62.0 71.5 51.37 68.74 1960 39.61 1943

Average for 10 or more years.2U.S. Weather Bureau records, 1921-60.

U. S. Weather Bureau records, 1943-60.

SINKHOLES

Sinkholes are common in areas underlain by limestone formations.Rainfall combines with carbon dioxide in the atmosphere to form a weakcarbonic acid. As the water percolates through the limestone, solutiontakes place and cavities of irregular shape are gradually formed. Whenthe cavities enlarge to the extent that the roof can no longer supportthe overburden, the surface deposits, generally sand, collapse intothe cavity and a sinkhole is formed. Many of Orange County's naturallakes, ponds, and closed depressions are the surface expression ofsuch collapse. Sinkholes range in size from small pits a few feet indiameter to large depressions several square miles in area. Largedepressionsare usually formed by the coalescence of several sinkholes.

Sinkholes may form either suddenly by collapse of the roof of alarge caverr or slowly by a gradual sinking of the ground surface. The


latter condition is illustrated by the formation of a sinkhole in the

Orlando area in April 1961. The sinking was first noted as a depression

in a graded road. By the following day a hole about 6 feet in diameter

had formed. Within 2 days the hole gradually increased to about 60 feet

in diameter and to about 15 feet in depth. The hole was filled and no

further development has been noted.

Another sinkhole occurred in April 1961 in Pine Hills, west of

Orlando. A depression about 1 foot deep and 50 feet in diameter formedduring April 23 and 24 and was marked only by a faint line in the sand

except where the outer edge intersected two houses. The floor of oneroom, the carport, and the concrete driveway of one house was badly

cracked. The corner of the other house dropped about 6 inches.

The slow rate of settlement was probably caused by a gradual

funneling of the overlying sand and clay into relatively small solution

channels in the limestone. The channels eventually became filled

and the subsidence stopped.

DRAINAGE

The eastern and southern parts of Orange County are drainedprincipally by surface streams. The St. Johns River and its tributariesdrain the eastern part of the county while Shingle Creek, Reedy Creek,

Boggy Creek, and canals in the upper Kissimmee River basin drainmost of the south-central and southwestern part. Many swamps andsloughs occur in the eastern and southern parts of the county becauseof the poorly developed drainage.

In the western and northwestern parts of the county much of thedrainage is to closed depressions and thence by seepage to the under-lying limestone or by evaporation from the lakes and ponds. A fewsinkholes have open connections with solution channels in the limestone.Water that collects in these sinkholes drains directly into the solutionchannels. Most of the sinkholes, however, are floored with relativelyimpermeable sediments and the rate of seepage through these lake-filled sinkholes may not be much greater than in areas adjacent to thelakes.

More than 300 drainage wells were drilled between 1906 and 1961in the upland area of the county, especially in Orlando and vicinity,to drain surface water directly into the artesian aquifer (fig. 3).

Sa5s 40' a3' 3' 25' 20' . lo " o' 0el Do ' 802 5 - I I I II I,1 1-1 1-1-1-1-1 1 1 1

A K I*"-^ ._~ . ...-..----

41 I

EXPLANATION _ - --45

----4_ _ - -3-5'd

, % -- WN'c II-: . . .

, - I ^ - - 2 - -- -0'

d --~- E-- -- --- 1- ---1 o.- ,. i---,--..---.-- =- -

I405 35 30 . . 0. ,,- 0 05' 800 o 80-50'

Se taken from U.S. Geologicol o a 0 me Well Inventory by W i Lichilar

I'24,000

Figure 3. Distribution of drainage wells in Orange Countyv Florida.

2wi^i ] @// V --- --- T

Figure 3. Distribution of drainage wells in Orange Countyj Florida. "'


The greatest activity was during 1960 when about 35 drainagewells were drilled. Considerable quantities of water are disposed ofin this manner, but figures on the total amount are not available. Thequality of the water that enters the aquifer through drainage wells rangesfrom pure rainwater to water used to flush cow barns.

GEOLOGY

The materials penetrated by water wells in Orange County rangein age from middle Eocene (about 50 million years ago) to Recent.The formations, in ascending order of age, include the Lake City Lime-stone, the Avon Park Limestone, and the Ocala Group of middle Eoceneage; the Hawthorn Formation of middle Miocene age; and undifferentiatedpost-Miocene deposits.

Sand and clay of the Hawthorn Formation and younger depositsgenerally cover the limestones to depths ranging from a few feet inthe northern part of the county to about 100 to 150 feet in the Orlandoarea and more than 350 feet in the eastern part of the county. Vernon(1950) has postulated that the western two-thirds of the county is partof the upthrown side of a faulted block called the Kissimmee faultedflexure. Indications of another fault exist in the St. Johns River marsharea with the upthrown side to the east. Further geologic data will becollected to aid in solving the complex structure underlying OrangeCounty. Table 2 summarizes the properties of the geologic formationspenetrated by water wells in Orange County.

HYDROLOGY

All natural supplies of fresh water are derived from precipitation.The cycle of precipitation, evaporation, and the intervening movementsof water is known as the hydrologic cycle. Some precipitation returnsalmost immediately to the atmosphere by evaporation, some is transpiredby plants, some is stored in surface or underground reservoirs beforebeing returned to the atmosphere by evapotranspiration, and some movesto the sea by surface or underground routes, eventually to be evaporatedagain.1 The stratigraphic nomenclature used in this report conforms generallyto the usage of the Florida Geological Survey. It conforms also to thenomenclature of the U. S. Geological Survey, except that Ocala Groupis used in this report instead of Ocala Limestone.

Table 2. Summary of the Properties of the Geologic Formations Penetrated by Water Wells in Orange County, Florida

Formation Thickness, Description of Water-bearing

Series. name in feet material properties Aquifer Water level

Recent Undifferen-and tiated; may

Pleistocene include 0-200 Mostly quartz sand with Varies widely in , Nonartesian 0-20 feet below theCaloosa- varying amounts of quantity and land surface but -nhatchee clay ahd shell quality of water generally less than O

Pliocene (?) Marl _________ produced 10 feet

Gray-green, clayey, Generally imper- Shallow artesian Piezometric surface not

quartz sand and silt; meable except for lower limestone defined, water level --

Miocene Hawthorn 0-200 phosphatic sand; and .limestone, shell, beds may be part generally is lower than"

buff, impure, phosphatic or gravel beds of Floridan nonartesian aquifer and

limestone, mostly in aquifer higher than Floridan '

lower' part aquifer

Cream to tan, fine, soft Moderately high trans-

Ocala 0-125 to medium hard, granu- missibility, mostGroup lar, porous, sometimes wells also penetrate

dolomitic limestone underlying formations

Upper section mostly Overall transmissibilitcream to tan, granular, very high, contains Piezometric surface 0

Eocene Avon Park 400-600 porous limestone. Often many interconnected Floridan shown in figures 10

Limestone, contains abundant cone- solution cavities, and 11

shaped Foraminifera. . Many large capacity

Lower section mostly wells draw water fror

dense, hard, brown,crys- this formation

talline dolomite

Dark brown crystalline Similar to Avon Park

Lake City Over 700. layers of dolomite alter- Limestone. Municipal

Limestone Total un-' nating with chalky fossili- supply of City ofknown' ferous layers of limestone Orlando obtained from

this formation

------------- _ -


All natural waters dissolve mineral matter from the soils androcks contacted. The quantity of mineral matter dissolved dependsmainly upon the type of material contacted and the length of the timeof contact. The solvent action upon mineral substances is greatlyincreased when the water contains dissolved gases, such as carbondioxide, which may be introduced from the atmosphere or from decayingorganic material. The most common mineral constituents dissolved inwater are silica, iron, calcium, magnesium, sodium, potassium, car-bonate and bicarbonate, sulfate, chloride, nitrates, and fluorides. Othermineral constituents may be present in minor amounts.

Dissolved organic material which is introduced into water whenit contacts living and decaying vegetation imparts color to the water.The color is generally more prevalent in surface water and shallowground water than in deep ground water.

At a particular, location ground water generally contains moredissolved mineral matter than surface water because it is in intimatecontact with the soil and rock. However, the quality of ground waterdoes not vary as much as that of surface water. During dry periods,the mineral content of surface water usually increases because of ahigher percentage of ground-water inflow and a longer time of contactwith soil and rock.

Dissolved mineral constituents in water are generally reportedin parts per million. One part per million (ppm) is one unit weight ofa constituent in a million unit weights of water. Hardness of wateris caused by the presence of alkaline earth metals such as calciumand magnesium and is expressed as an equivalent quantity of calciumcarbonate. The hardness scale generally used by the U. S. GeologicalSurvey classifies water with a hardness of 0 to 60 ppm as soft; 61 to120 ppm as moderately hard; 121 to 200 ppm as hard; and over 200 ppmas very hard. Specific conductance is a measure of the ability of waterto conduct an electric current and may be used in estimating the totaldissolved mineral content. The total dissolved mineral content of mostsurface water in Orange County is between 50 and 60 percent of theconductivity. Thus, by making a simple conductivity measurement,the mineral content can be estimated by multiplying the specific con-ductance by a factor of 0.55. The mineral content of ground water inOrange County can be estimated by multiplying the specific conductanceby a factor of 0.62. Color is expressed in units of the platinum-cobaltscale. Hydrogen-ion concentration (pH) is a measure of the acidity or


alkalinity of a solution. A pH value of 7.0 is neutral. Progressivevalues of pH above 7.0 denote increasing alkalinity, and regressivevalues below 7.0 denote increasing acidity.

SURFACE WATER

Most of the surface water in Orange County is from rain within thecounty, but some of it is from rain on adjacent areas of higher elevationthat flows into the county. The surface water is only temporarily storedin the lakes, swamps, and stream channels. The amount in storagecontinuously changes because the rate of replenishment differs from therate of depletion.

Permanent lakes are the most reliable sources of surface waterin Orange County. Swamps and marshes are intermittent sources thatgo dry after relatively short periods of drought.

The St. Johns River, the Wekiva River, and the Little Econlock-hatchee River north of State Highway 50 are the only streams in thecounty that do not either go dry or recede to extremely low base flowsin most years. The flow of the St. Johns River is sustained in all butextreme droughts by water stored in several large lakes that are a partof its main stem. The Wekiva River is sustained at relatively highbase flow by several springs. The lower Little Econlockhatchee Riverreceives water from the Orlando sewage system.

Surface-water data have been collected at 62 sites in the county.Figure 4 lists the sites where data have been collected systematicallyand shows the periods of record. Table 3 lists the sites where miscel-laneous data have been collected.

Surface water from the southwestern 340 square miles of OrangeCounty drains to the south into the Kissimmee River. Surface waterfrom the eastern and northern 660 square miles of the county drainsto the north into the St. Johns River. Figure 5 shows the drainagebasins and the surface-water data collection points in Orange County.

KISSIMMEE RIVER BASIN

Reedy Creek: Reedy Creek drains 49 square miles in the south-,west corner of Orange County. The drainage from about 22 square milesof this basin in Lake County flows into Orange County.


taM- Station

It dIrLake, at Orlando

Z jal-East Tohopekallga Canal nr Narcoossee '2

3 ApophaL-Beauci Can4a at conrsol m Astatula

-Aoa- o4cai Caol at State Hwy 448. ncAslatu c5 pka. Lake. at Winter Garden6 oss Lake nc Orlando

7 B ,esi Lake, at Windermere

81 8iq Sand Lake at Doctor Phillips

9 Ioggy Creek n Kissimmeet0 Bggy Creek nc Taft I

t I utter, Lake, at Windermere12 Concord, Lake, at Orlando13 Conway, Lake, ca Pinecastle14 Carrine, Lake, r. Orlando

15 Cypress Creek at Vineland

6 lsston Canal nr Wewahotee

7 oraT Lake, at Mount Dora I. .

18 Econlockhatchee River nc Bithio9 Econlockhatchee River nc Chuluota

20 Fairviw, Lake, at Orlando21. Hart Lake, nt Norcoossee

22 Nigland, Lake, at Orlando

23 vanhae, Lake, at Orlando

24 lm Creek 1n Christmas

25 Johns Lake at Oakland 1

7

26 tle Econlockhatchee River nr Union Parki

27 ae Lake Foirview at Orlando-

2z Biln~ Lake, at Winter Park29 Sari Jane Lake nr Norcoossee

30 iMr Jane-Hart Canal r. Norcoossee* *

3t MIrle-Mary Jane Canal nr. Norcoossee

32 r t

Lake at Orlando

33 Poinsett, Lake, nr Cocoa

34 Rowena, Lake, at Orlando

35 St Johns River nr. Christmas

36 St Johns River no Cocoo

37 St Johns River Flood Profile38 Shingle Creek oat airport, nr. Kissimmee39 Stingle Creek nr. Vineland

40 Silver, Lake, at Orlando

4 t Spier Lake, nr Orlando

42 Spring Lake at Orlando43 Sue, Lake, at Orlando

44 Susannah, Lake, nr. Orlando

45 Hdm9rhin, Lake, at Orlando

46 W *iva River r. Sanford i 9 s

47 Wenonah (Francis) Lake nr Plymouth

EXPLANATION

Daily to weekly stage

Monthly stage or annual flood crest 1n i

Periodic discharge measurements i" . **......** ... ....... *- ...........

Daily stage and discharge F. :;: ::::.:.:::.:::: • •:·:•

Figure 4. List and duration of records at surface-water gaging stations in or

near Orange County, Florida.

5 45' 40' 35' 3 ' 20 ' 05' 55' '

50 0 i .-- ; Limit of f looedig i n St. Johns River marsh4. 1W 'e -and Atowns-

1 - Surface wafer dolo collection poinstatuL 1 e .. Qu.o*.w eample ediscilan pow, surf", tssur s

= i 19 S.7 .. on num1 S rla )i o I nfg R re r 4 o bt 3

0 Its 0

4O

J# --I0

z

el4 035 30 2' 20 5' 0 05 5 o 55 80o 5

30' 3

Figure 5. Drai-age basins and surface-water data collection points in Orange County, Florida.-

2V - 25'

-p 0 L K 20'

28,17'2al 15' 10. t1 : 585' GO

'

Bsae taken from USGeologlCo l O I ;• _45 L 6 .1 9 9 I10 tes

Survey Iopogrophic quadrangles,1;24,000

Figure 5. Drainage basins and surface-water data collection points in Orange County, Florida. %


Table 3. Sites Where Miscellaneous Surface-Water Data Have Been Collected

In And Near Orange County, Florida(Station number corresponds to that shown for figure 5.)

Station number Station

48 Bonnet Creek near Vineland

49 Christmas Creek near Christmas

50 Howell Creek near Maitland

51 Jim Branch near Narcoossee

52 Little Wekiva River near Forest City

53 Mills Creek near Chuluota

54 Reedy Creek near Vineland

55 Roberts Branch near Bithlo

56 Rock Springs near Apopka

57 Second Creek near Christmas

58 Settlement Creek near Christmas

59 Taylor Creek near Cocoa

60 Tootoosahatchee Creek near Christmas

61 Wekiva Springs near Apopka

62 Witherington Spring near Apopka

Elevations in Reedy Creek basin in Orange County range from75 feet at the southern county line to 210 feet at Avalon fire lookouttower. The eastern part of the basin is relatively flat swampy terraininterspersed with islands of low relief. The western part is rollinghills interspersed with lakes and swamps. The divide between ReedyCreek basin and Bonnet Creek basin to the east is rather indefinite,and some interchange of water occurs between basins.

At Reedy Creek near Vineland (station 54), 1 mile south of thecounty line, the minimum flow observed was less than 0.01 cfs (cubicfeet per second) in May 1961. The maximum flow was 1,940 cfs at thepeakof the flood in September 1960.

Analyses of water collected from Reedy Creek at station 54 atlow flows on June 15, 1960, and May 23, 1961, show the water to bevery soft and low in mineral content. At almost zero flow on May 23,


1961, the hardness was 11 ppm, and the mineral content, based on aconductivity measurement, was estimated at 24 ppm.

Bonnet Creek: Bonnet Creek and its tributary, Cypress Creek,drain 55 square miles of Orange County, east of Reedy Creek basin.The part of the Bonnet Creek basin that is drained by Cypress Creekdiffers hydrologically from the rest of the basin.

Elevations in Bonnet Creek basin range from 75 feet at the countyline to 195 feet near Windermere. Elevations in the western part of thebasin, the part excluding Cypress Creek basin, range from 75 to 100feet. This area is flat and swampy but contains several lakes of moderatesize and islands of low relief.

The minimum flow observed at Bonnet Creek near Vineland (station48), 1 mile south of the county line, was 0.4 cfs in May 1961 and themaximum flow was 1,180 cfs at the peak of the flood in September 1960.

The water in Bonnet Creek has a slightly higher mineral contentand less color than the water in most other streams in the county. OnNovember 24, 1959, theimineral content was 107 ppm, the hardness was66 ppm, and the color was. 10 units. The higher mineral content andlower color are probably due to ground-water inflow.

Cypress Creek basin is comprised of about 8 square miles of lakes,2 square miles of swamps, and 22 square miles of rolling hills in theeastern part of Bonnet Creek basin. Elevations range from 90 feet atits junction with Bonnet Creek to 195 feet near Windermere.

The flow from Cypress Creek basin has been gaged at Vineland(station 15) since 1945. The average annual runoff is about 4 inchesand ranged from a minimum of 0.3 inch in 1955 to a maximum of 17.72inches in 1960. In 10 of the 15 years of complete record, at least oneperiod of no flow occurred. The longest period of no flow was 107 daysin 1956. The maximum flow recorded was 354 cfs in September 1960.

Shingle Creek: Shingle Creek drains 83 square miles of OrangeCounty west of U.S. Highway 441 and south of State Highway 50.

Elevations range from 70 feet at the county line to 175 feet nearWindermere. The basin is relatively flat and altitudes are generallyless than 105 feet except for rolling hills on the western fringe. A closed'depression occupies 3.3 square miles of the northern part of the basin.


Continuous records of stage and discharge for Shingle Creek near

Kissimmee (station 38) have been obtained since October 1958. The

maximum discharge of record at this station was 3,320 cfs in March 1960.

Periodic observations of stage and discharge near Vineland (station 39)

have been obtained since September 1959. At this station, the maximum

discharge was 1,740 cfs in March 1960. In most years there is no flow

for many days at either site.

The water in Shingle Creek near Vineland (station 39) has low

mineral content and is soft. Dissolved organic material, usually about

50 percent of the dissolved solids, causes high color, especially during

the early periods of high flow. The dissolved solids, including organic

material, are less than 165 ppm and the hardness is usually less than

30 ppm. Color ranges from 55 to 200 units.

Boggy Creek: Boggy Creek drains 86 square miles of the county

in and south of Orlando. An area of about 11 square miles in the upper

part of the basin has no surface outlet and drains underground.

Elevations range from 60 feet at the county line to about 125 feet

in the upper basin. The lower part of the basin is flat and contains

many swamps and marshes but relatively few lakes. The upper part

of the basin is rolling hills interspersed with many lakes.

Periodic measurements of the discharge of Boggy Creek near

Kissimmee (station 9) were made from January 1955 to September 1959.

Since September 1959, continuous records of the discharge of Boggy

Creek near Taft (station 10) have been collected. The maximum dischargeduring the period of record was 3,680 cfs in March 1960, and the minimumwas 0.1 cfs in June 1961.

Analyses of water collected periodically from Boggy Creek show

that the water is soft, low in mineral content, and high in color. The

total dissolved material ranged from 59 to 115 ppm, and the dissolvedmineral content ranged from 29 to 62 ppm which indicates that about

50 percent of the total dissolved material is organic. Color intensityranged from 45 to 140 units and was usually highest during the earlypart of flood periods. The hardness of the water is less than 20 ppm.

Jim Branch: Jim Branch drains 5.8 square miles in the south-

central port of Orange County. Elevations in the basin range from 75to 85 feet.


The maximum flow of Jim Branch near Narcoossee (station 51)has not been determined. A dry stream channel has been observed atthis station.

Water collected from Jim Branch at low flow on May 23, 1961was very soft (9 ppm) and low in mineral content (30 ppm, estimatedfrom its conductivity).

Ajay-East Tohopekaliga Canal: This canal drains approximately171 square miles, of which 54.5 square miles are in Orange Countyand 116.5 square miles are in Osceola County.

Elevations of the drainage area in Orange County range from 60to 90 feet. The topography is fairly flat and is characterized by swampsin the northern part and by lakes in the southern part.

Periodic measurements of the flow in Ajay-East TohopekaligaCanal near Narcoossee (station 2) have been made since 1942. Themaximum measured discharge was 1,420 cfs in March 1960. A reverseflow of 0.25 cfs was measured in February 1946. The average dis-charge, based on the relation between drainage area and average dischargeat several points on the main stem of the Kissimmee River, is estimatedto be about 170 cfs.

The flow into Orange County from an area of 111 square miles inOsceola County has been measured in Myrtle-Mary Jane Canal nearNarcoossee (station 31) since November 1949. The maximum flow intothe county via this canal was 990 cfs in September 1960. In September1956, the flow reversed for 2 days and flowed out of the county at therate of 17 cfs. The average discharge in this canal for the period 1950to 1960 was 129 cfs.

Water from Ajay-East Tohopekaliga Canal, collected at station 2during low flow on May 23, 1961, was very soft (16 ppm) and low inmineral content (39 ppm, estimated from its conductivity).

ST. JOHNS RIVER BASIN

St. Johns River: The St. Johns River is the eastern boundary ofOrange County. Small tributaries drain 174 square miles of OrangeCounty directly to the St. Johns River. An additional 490 square miles

,of the county are drained to the St. Johns River by tributaries whichflow across the county line before joining the main stem.


The St. Johns River slopes very little in its approximately 20-mile

reach along the border of Orange County. At flood stages, the riverfalls from an elevation of about 17.5 feet at Lake Poinsett to about 10.5feet at the northern county line. At the minimum stages in 1945, theriver fell from 8.0 feet to minus 0.4 foot in this reach.

Stage and discharge records have been collected at St. JohnsRiver near Christmas (station 35) since December 1933 and at St. JohnsRiver near Cocoa (station 36) since October 1953. The average dischargefor the period of record at station 35 was 1,431 cfs. For the 7-yearperiod October 1953 to September 1960, the average discharge at station35 was 1,689 cfs; and at station 36, 1,431 cfs. The maximum flow atstation 35 was 11,700 cfs in October 1953. There was no flow at station35 for periods during March, April, and June 1939.

Large quantities of water may be stored in the wide channel andin lakes in the St. Johns River valley.

Analyses of water collected daily from the St. Johns River atstation 36 from October 1953 to September 1960 and a continuous recordof its conductivity since June 1959 show that the quality of the watervaries greatly.

Figure 6 shows the relation of specific conductance to streamflow for the St. Johns River at station 36 from June 1958 to July 1961.The mineral content in the water varies inversely with stream flow be-cause the percentage of mineralized ground water in the stream is greatestduring low flows. The scatter of the plotted points may be due to thevariable inflow of highly mineralized artesian water though possibly inpart to the problem of representative sampling. Inflow from one welloccurs just above the conductivity recorder, but it is doubtful if waterfrom this single well causes all of the variations in conductivity. Duringthe period 1953-60, the dissolved solids in water from the St. JohnsRiver ranged from 103 ppm October 21-31, 1953, to 998 ppm July 11-20,1956; the hardness ranged from 30 ppm October 21-31, 1953, to 294 ppmJune 11-20, 1956; specific conductance ranged from 107 micromhosOctober 10, 1953, to 1,620 micromhos June 18, 1956; and the watertemperature ranged from 460 F January 9-12, 1956, to 95°F August 9,1956. The chloride content reached a maximum of 403 ppm at a meandischarge of 41 cfs during the period June 11-20, 1956. This chlorideconcentration is enough to taste slightly salty to most people (Hem,1959).

1000

'800W "f* ------- --:--- --

' 800' --

400-*

s *--- . *- -

s____. *__ - . zCS 1 *

200 * *

100 ----100 200 400 100 2000 400 7000 1000

Mean discharge in cubic feet per second

Figure 6. Relation of specific conductance to stream flow, St.Johns River at station 36, near Cocoa, Florida, 1958-61.


Small tributaries draining to east: The eastern part of the countybetween the main stem of the St. Johns River and the EconlockhatcheeRiver, amounting to about 180 square miles, is drained to the St. JohnsRiver by numerous small tributaries. Table 4 shows data pertinent tothese tributaries.

During the low flow period from June 14 to 17, 1960, the dissolvedmineral content of the water in the small tributaries draining eastwardinto the St. Johns River was estimated from conductivity measurementsto range from 33 ppm in Taylor Creek to 86 ppm in Second Creek. Themineral content of the water in Christmas Creek was estimated to be52 ppm on May 24, 1961, when the other small tributaries were dry.

Table 4. Data on Small Tributaries Draining the Eastern Part of Orange County,

Florida

Drainagearea Elevation

Station (square (feet) Discharge (cfs)

Subdivision of area number miles) Max. Min. Max. Date Min. Date

Taylor Creek nearCocoa 59 8.74 75 14 3,000 Mar. 0 *

1960Sweetwater Branch -- 4.31 50 16 --- --- 0 *

Ji• Creek nearChristmas 4 31.4 75 11 3, 750 Mar. 0 *

1960Second Creek near

Christmas 57 17.3 76 17 1,500 Sept. 0 *1960

Settlement Creeknear Christmas 58 8.86 76 17 --- -- 0 *

Tootoosahatchee Creek

near Christmas 60 23.6 76 14 --- --- *

Near Creek -- 6.52 72 13 --- --- *

Unnamed Creek -- 4.37 61 12 -- --- 0

Christmas Creek 49 15.0 71 11 --- --- 0.04 June

1961

Buscombe Creek I -- 2.15 56 11 --- --- 0

Roberts Branch 55 5.05 72 37 --- -- 0 *

Area withoutdefinite channels -- 13.4 46 14 --- --- 0 *

St. Johns Riverflood plain -- 40.2 18 4

* Many days in most years.


Lake Pickett: Lake Pickett and its contributory drainage areaoccupy 8.1 square miles. Mills Creek drains Lake Pickett to the Econ-lockhatchee River. Elevations in the Lake Pickett drainage basin rangefrom 60 to 75 feet.

The hardness of the water in Mills Creek at Chuluota (station 53)on May 24, 1961, was 7 ppm. and the mineral content, estimated fromits conductivity, was 21 ppm. The pH of the water was 5.9 indicatingthat it is slightly corrosive. The water quality of Lake Pickett probablyis similar to that of Mills Creek.

Econlockhatchee River: The Econlockhatchee River drains 117square miles of Orange County. The drainage basin ranges from 2.5 to9.5 miles wide and the average width of the basin in Orange Countyis 6.2 miles. The basin is about 14 miles east of Orlando and spansthe county from south to north. The drainage from 17 square miles ofthe basin in Osceola County enters Orange County. Elevations in theEconlockhatchee River basin in Orange County range from 20 to 90feet.

The Econlockhatchee River basin and the area drained by smalltributaries to the St. Johns River are unusual for Orange County in thatthey contain only three lakes of significant size. These basins do,however, contain many swamps and marshes.

Continuous records of the flow of the Econlockhatchee Rivernear Chuluota (station 19) have been collected since 1936, and periodicmeasurements of the flow of the Econlockhatchee River near Bithlo(station 18) have been made since September 1959. The maximum flowat station 19 was 11,000 cfs and at station 18, 7,840 cfs. The minimumflow at station 19 was 6.7 cfs in June 1945. The river flow ceases atstation 18 in most dry years. The average flow at station 1.9 was 266cfs for the period 1936 to 1960.

A continuous conductivity record since October 1959 and analysesof water collected periodically from the Econlockhatchee River nearBithlo show the water to be high in color, soft, and low in mineral con-tent. The conductivity ranged from 24 to 189 micromhos and the colorranged from 45 to 240 units. The color is always greatest during the

early part of high flow periods.

Figure 7 shows the cumulative frequency curves of specific con-iductance for the Econlockhatchee River at station 18 for the 1960 and


160 - -- - -

o 140

a 80

0

061

20

S(o - - -- -----i---- -

o

2 5 10 30 50 70 90 99

Percent of time specific conductance was equal to or less thanthat shown

Figure 7. Cumulative frequency curves of specific conductance for the Econ-lockhatchee River at station 18, near Bithlo, Florida, 1960-61.

and 1961 water years (October 1 to September 30). These curves maybe used to estimate the mineral content of water in the river for anypercentage of time. For example, the conductivity was 130 micromhos orless for 80 percent of the time in the 1961 water year whereas in 1960the conductivity never exceeded 120. The mineral content of water inthe Econlockhatchee River averages about 0.55 of the conductivity;therefore, the dissolved mineral content would be 72 ppm (130 x 0.55)or less for 80 percent of the time during the 1961 water year. The mineralcontent of the water in the Econlockhatchee River was lower in 1960than in 1961 because of greater dilution by surface runoff in 1960.

g80 - -- y ---

4 0.---- -- ^-- - ------

20 ^-- ---- -------

than in 1961 because of greater dilution by surface runoff in 1960.


Little Econlockhatchee River: The Little Econlockhatchee River

drains 71 square miles of Orange County east of Orlando. Elevationsin this basin range from about 35 feet near the county line to 127 feetat the eastern edge of Orlando.

A few lakes exist along the western rim of the basin but noneexist elsewhere. Many swamps and marshes temporarily store waterand thereby reduce the magnitude of peak flows in the river.

The flow from the upper 27 square miles of the basin has beengaged since October 1959 at Little Econlockhatchee River near UnionPark (station 26). The maximum and minimum flows at this stationwere 1,640 cfs in March 1960 and 0.1 cfs in June 1961. The averageflow for the period October 1959 to May 1961 was 36 cfs.

Effluent from the Orlando sewage plant is discharged into theriver just north of State Highway 50. The amount of effluent rangesfrom 5 to 12 mgd (million gallons per day) and averages about 7 mgdoral communication, Mr. Reed Terry, Orlando Sewage Plant).

Analyses of water collected from the Little EconlockhatcheeRiver at station 26 show that the quality is similar to that of the Econ-lockhatchee River. Color ranged from 30 to 32 units and was highestduring high flow periods. The dissolved solids content of the waterranged from 83 to 140 ppm, mineral content ranged from 35 to 75 ppm,and the water hardness did not exceed 48 ppm.

Howell Creek: Howell Creek drains about 20 square miles inOrange County, mostly in the suburban areas of Maitland, Winter Park,

and the northern half of Orlando. Elevations in the Howell Creek basinrange from about 55 to 125 feet.

This basin contains a chain of lakes connected by natural channels,canals, and culverts, beginning at Spring Lake at Orlando (station 42),

at an elevation of about 88 feet and ending at Lake Maitland at WinterPark (station 28), at an elevation of about 66 feet. Several other lakes

are connected to the chain of lakes by canals or culverts. Lake Under-hill at Orlando (station 45), in the Boggy Creek basin, is connected

to Lake Highland in the Howell Creek basin by a culvert.

The flow of Howell Creek near Maitland (station 50) has beenZmeasured several times. The maximum discharge was about 160 cfs


in September 1960. Flow at this site ceases when the level of LakeMaitland is below about 65.5 feet with the center board of the controlout or about 66.0 feet with the center board in. The levels of manyof the lakes in the basin are partly controlled by drainage wells andthe flow from the basin is accordingly modified.

The water in Howell Creek and Lake Maitland are similar andare of good quality except for moderate hardness. Hardness at highand low lake levels was 65 and 81 ppm, respectively. The dissolvedsolids at high and low lake levels were 128 and 147 ppm, respectively.

Wekiva River: The Wekiva River and its tributaries, the LittleWekiva River and Rock Springs Run, drain about 130 square miles inOrange County. Elevations in this basin range from about 15 feet atthe northern county line to about 195 feet near Windermere.

The area near the stream channels is flat and swampy, and rangesin elevation from about 15 to 30 feet. From the edges of these flatswamps, rolling hills rise abruptly to elevations ranging between 60 and100 feet. More than half of the Wekiva River basin in Orange Countyconsists of rolling hills interspersed with lakes and sinks. There isno surface outflow from this area.

Records of the daily stage and discharge of the Wekiva Rivernear Sanford (station 46) have been collected since October 1935. Thecontributing drainage area at this station is about 200 square miles.The average discharge for the period 1935-60 was 273 cfs. The maximumdischarge was 2,060 cfs in September 1945 and the minimum, 105 cfs inJune 1939.

The flows of Rock Springs, Wekiva Springs, and WitheringtonSpring (stations 56, 61, and 62) near Apopka in the Wekiva River basin,have been measured occasionally since 1931. Table 5 shows the resultsof these measurements.

During low flow on May 25, 1961, the hardness of the water of theLittle Wekiva River at Forest City (station 52) was 41 ppm and themineral content, estimated from the conductivity of the water, was 90 ppm.

The quality of water from Rock Springs, and Wekiva Springs, issimilar to the ground water in the area, and variations with flow aresmall.


Table 5. Discharge Measurements of Springs in Orange County, Florida

Downstream location

of,measuring section

Name of spring and Date of Discharge in relation to head of

station number measurement (cfs) (mgd) spring (feet)

Rock Springs (56) Z- 5-31 55.9 36. 1 50.3- 8-32 51.9 33.5 502-10-33 54.2 35.0 401-30-35 62.8 40.6 80

11- 7-35 57.1 36.9 5012- 6-35 62.8 40.6 5001- 4-36 54.9 35.5 : 600

1- 4-36 56.2 36.3 606- 7-45 52.5 33.9 505- 9-46 59. 1 38.2 304-26-56 54.7 - 35.4 1,000

11-24-59 70.0 45.2 150

11-24-59 72.4 46.8 1,200

6-17-60 78.2 50.5 1,25010-17-60 83.2 53.8 1,250

5-25-61 68.4 44.2 1,300

Wekiva Springs (61) 3- 8-32 63.9 41.3 lob

2-10-33 66.9 43.2 100-,11- 7-35 72.5 46.9 3006- 7-45 64.8 41.9 2005- 9-46 67.5 43.6 150

4-27-56 62.0 40.1 200

11-25-59 88.8 57.4 3006-17-60 86.0 55.6 200

10-17-60 91.7 59.3 150

5-25-61 86.6 56.0 150

Witherington Spring

(62) 8- 8-45 4.69 3. 03 4,22410-19-60 12.0 7.76 4,752.

Apopka-Beauclair Canal: This canal drains Lake Apopka andthe surrounding areas. The total area drained by the canal is about

180 square miles, of which about 120 square miles is in Orange County.Elevations in this basin range from about 65 feet in the mucklands ad-

jacent to Lake Apopka to m6re than 210 feet near Avalon lookout tower.

The flow in Apopka-Beauclair Canal near Astaula was measuredperiodically at station 3 from 1942 to 1948. Since July 1958 the dailyflow has been determined at station 4. The maximum flow at station 4

was 754 cfs in March 1960 and the minimum flow was estimated to beabout 5 cfs during periods when a control structure in the canal wasclosed.


LAKES, SWAMPS, AND MARSHES

Orange County has about 1,100 permanent bodies of open waterand hundreds of intermittent marshes and swamps. The vast majorityof the lakes are in the western half of the county. Swamps and marshesoccur in all parts of the county but are less prevalent in the northwesternpart than elsewhere in the county.

The lakes range in altitude from about 20 to 155 feet and in size

from less than 1 acre to nearly 47 square miles. Records of the levelsfor the lakes listed in figure 4 have been collected by the U.S. Geolog-ical Survey for the periods shown. Records for many additional lakeshave been collected by the engineering departments of the city of Orlandoand Orange County.

Because of relatively large volumes of water stored in lakes,the quality does not change as rapidly as in streams. Some changesin the quality of the water in lakes occur because of dilution, by highrunoff, and because of ground-water inflow and concentration of mineralmatter by evaporation.

Water from Lake Hart near Narcoossee (station 21) has been ana-lyzed semiannually since October 1954. This water has high color, lowpH values, and low dissolved mineral content. The color ranged from50 units on October 8, 1958, to 170 units on November 8, 1956. The pHvalues, which ranged from 5.5 to 6.2, indicate that the water is slightlycorrosive. The dissolved mineral content was low and ranged from 20to 34 ppm.

The water in Lake Apopka at Winter Garden (station 5) is hardand high in calcium bicarbonate, indicating large quantities of ground-water inflow. During the low stage in May 1961 the calcium contentwas 29 ppm, the bicarbonate was 123 ppm, and the water hardness was126 ppm.

Water collected from Johns Lake at Oakland (station 25) duringhigh stage on October 29, 1959, had a hardness of 30 ppm, a mineralcontent of 77 ppm, and a color of 80 units.


GROUND WATER

Ground water is the subsurface water in the zone of saturation -thezone in which all the openings of the soil or rock are completely filledwith water under atmospheric or greater pressure. Ground water occursunder nonartesian or artesian conditions. Nonartesian conditions occurwhen the upper surface of the zone of saturation (the water table) is notconfined and accordingly is free to rise and fall. Artesian conditionsoccur when an aquifer (water-bearing formation or group of formations)is confined by relatively impermeable beds and the water is under greaterthan atmospheric pressure.

The heights to which water will rise in tightly cased wells thatpenetrate an artesian aquifer define its pressure or piezometric surface.The piezometric surface is not directly related to the water table andmay be above, below, or at the same level as the water table. Wherethe water table is above the piezometric surface the nonartesian watermay infiltrate through the confining layer to the artesian aquifer. Suchareas are recharge areas to the artesian aquifer. Conversely, wherethe piezometric surface is above the water table, the artesian watermoves upward and the area is a discharge area of the artesian aquifer.As no confining bed is completely impermeable, some leakage up ordown usually occurs; however, where the confining bed is composedof a thick section of dense material, such as clay, the amount of leakageis relatively small.

Ground water in Orange County occurs in a shallow nonartesianaquifer, in several shallow artesian aquifers, and in the Floridan aquifer,

which is artesian in Orange County.

NONARTESIAN AQUIFER

Aquifer properties: The nonartesian aquifer in Orange Countyextends from the water table to about 30 or 40 feet below land surface.

It is composed mainly of quartz sand with varying amounts of clay,

hardpan, and shell material. The nonartesian aquifer extends over

most of the county, but its composition and thickness and consequently

its productivity vary and there may be many local areas where it will

not produce enough water to supply a well. Most wells in the nonartesian

aquifer are small diameter sand-point or screened wells, 20 to 30 feet

deep, that yield small to moderate quantities of water.


Water levels: The depth to the water table in Orange County

ranges from 0 to about 40 feet below the land surface. The data avail-able indicate that the yearly fluctuations of the water table range froma few feet in low-lying parts of the county to more than 20 feet in higherareas. Figure 8 shows the hydrograph of one well (832-105-3) in the

83-08 I I

,°»--, i- i ~~-- ----

C" S-- - -

|^h4-I--- --- l---_ - .I i I L

S -I i ; L

, ,0,--a-- - ^ - T7;_ \- -- - --_ , f A^, -- -t_, _ i _ _ _l ! i I ^ i

z i-j-.-LJ I

^[ 832'*C3 | ..t l. - • ; ;./, . iI -~/4

ýy J_#& AX WG SM t CT ,0V DE

Figure 8. IHlydrographs of observation wells in Orange County and rainfall atOrlando, Florida.


nonartesian aquifer in comparison with the hydrographs of observationwells in the artesian aquifer in Orange County. The graph shows thatat that location the water level fluctuated less than 2 feet in 1961.The lowest level was in early June, the beginning of the wet season.

Recharge and discharge: Practically all the recharge to the non-artesian aquifer in Orange County comes from rainfall within or nearthe county. Most of the county is blanketed with permeable sand whichallows the water to infiltrate rapidly. In much of the eastern and southernparts of the county, where the land is flat and an impermeable layer of

hardpan is near the surface, the overlying surface sands are quicklysaturated during the rainy season and many swamps and sloughs areformed.

Discharge from the nonartesian aquifer in Orange County is byevapotranspiration, seepage into surface-water bodies, downward leakageto underlying aquifers, seepage out of the county, and pumpage. Thehydrographs of wells 832-105-1, 2, and 3, in figure 8, show that in thethe vicinity of these wells (fig. 9) the water table was consistentlyabove the pressure surfaces in the underlying artesian aquifers andaccordingly some shallow water probably discharged downward.

Quality of water: Water collected from a selected number of wellsin the nonartesian aquifer shows a range in chemical composition. The

water.from wells developed in clean quartz sand is usually very soft(hardness generally less than 25 ppm) and low in mineral content (about

20 to 50 ppm). The very soft water often has low pH value - indicatingthat it is corrosive.

Total mineral content as high as about 500 ppm (estimated from

conductivity measurements) and high concentrations of some constituentsindicate that the water in some wells in the nonartesian aquifer is pol-luted. The water from well 822-138-3 (fig. 9) had concentrations of

potassium (10 ppm), sulfate (107 ppm), and nitrate (173 ppm), which

definitely indicates a possible nearby source of pollution. Use of water

containing an excess of 45 ppm of nitrate for feeding formulas for infants

results in methemoglobinemia or cyanosis (blue babies) in the infants.

A high concentration of nitrate was found only in well 822-138-3. The

waterfrom some of the nonartesian wells had as much as 90 units of color.

1 I II III I ' 11 't . I " , , I [• (• I I I .IC)Y

fil . 40 3b 3O hla Id 1 0 , 1 bw0

S4 r -* n-ed 4 K C00 UET

S--- -- -- -- --

__.. ....-. ^-<-.-.S -I-OE--.------------------------------- "

- F-

At Lrn

: ..-. '--..-,^..--- --- .-.---- -- 0t

i., , .. . .d_ 1 . L -, . .. - - -.

S40

| ~I35 I I I 20 10 0" ' 8100 55 --

Survey topographic quadrangles1124,000

Figure 9. Orange County, Florida, showing location of Inventoried wells other than drainage wells.

, : : - - -: :----- - ^ -",, I.- --

Bose tokln from U.S. Gologlcol 0 I i 3 4 8 6 7 6 9 IOmllilSurve/ topographic quodronglei.

H124,000

Figure 9. Orange County, Florida, showing location of inventoried wells other than drainage wells.


SHALLOW ARTESIAN AQUIFERS

Aquifer properties: Several shallow artesian aquifers occur withinthe confining beds of the Hawthorn or younger formations at depthsranging from about 60 feet to more than 150 feet below land surface.These aquifers are composed of discontinuous shell beds, thin limestonelayers, or permeable sand zones. The shallow artesian aquifers aremost productive in the area east and south of Orlando, where they yieldquantities of water sufficient for domestic use to screened or open-endwells.

Water levels: The only record of water-level fluctuations in ashallow artesian aquifer is from well 832-105-2 (depth 75 feet) (fig. 8).The range of fluctuation in this well, for the period of record, was about3.5 feet, or from 7 to 10.5 feet below land surface. At this location theshallow artesian water level is 6 to 12 feet below the nonartesian waterlevel and 6 to 14 feet above the water level in the Floridan aquifer.

Recharge and discharge: Recharge to the shallow artesian aquifersis mostly by leakage through overlying beds or by upward leakage fromunderlying beds where the piezometric surface in the Floridan aquifer isabove the piezometric surface in the shallow artesian aquifer. A smallamount of water probably flows into the county from surrounding countieswithin the shallow artesian aquifers.

Discharge from the shallow artesian aquifers is by downwardleakage to the Floridan aquifer, upward leakage to the nonartesianaquifer where the piezometric surface is above the water table, under-ground flow out of the county, and pumpage.

FLORIDAN AQUIFER

The principal artesian aquifer that underlies Orange County is apart of the Floridan aquifer which underlies Florida and parts of Alabama,Georgia, and South Carolina. The Floridan aquifer, as defined by Parket(1955, p. 189), includes "parts or all of the middle Eocene (Avon Parkand Lake City limestones), upper Eocene (Ocala limestone), Oligocene(Suwannee limestone), and Miocene (Tampa limestone) and permeableparts of the Hawthorn formation that are in hydrologic contact with therest of the aquifer."


Aquifer properties: The Floridan aquifer in Orange County iscovered by a layer of sand and clay which ranges in thickness fromabout 40 to 350 feet. The total thickness of the aquifer is unknownand it may include formations older than the Lake City Limestone.Supply wells for the city of Orlando penetrate more than 1,300 feet ofthe aquifer.

The lithology of the Floridan aquifer is variable but, in general,it is composed ofalternating layers of limestone and dolomite, or dolomiticlimestone. The limestone layers are usually softer and of lighter colorthan the dolomitic layers. The upper part of the aquifer is mostly cream totan limestone and the lower part is mostly light to dark brown dolomite ordolomitic limestone. In many parts of the county persistent layers ofdense, hard, dark brown, dolomitic limestone occur between depths of.about 400 and 600 feet below land surface.

Although the permeability of the dolomite is extremely low, thedolomitic zones contain many interconnected solution cavities and chan-nels that make its overall permeability very high. Tests made by Unkles-bay (1943, p. 13) show that wells with open hole between depths of60 and 450 feet and wells with open hole between 550 and 1,000 feetbelow land surface have the same water level and fluctuate together,indicating that the solution channels are interconnected vertically aswell as horizontally.

Solution channels, ranging in diameter from a fraction of an inchto many feet probably occur throughout the aquifer but are most preva-lent at depths between 200 and 600 feet and between 1,100 and 1,500feet below the land surface. Cavities 15 feet or more in depth havebeen reported by drillers. Large diameter wells in the Floridan aquiferwill yield more than 4,000 gpm.

Piezometric surface: The piezometric surface of the Floridanaquifer in Orange County slopes to the east and northeast from its highestpoint in the southwestern part of the county (fig. 10,11). Water movesdowngradient, from areas of high piezometric level to areas of lowerpiezometric level. In general, the direction of movement is at right anglesto the contour lines. The arrows in figures 10 and 11 show the generaldirection of movement of water in the Floridan aquifer. Because of the

cavernous nature of the aquifer the actual direction of movement of waterat particular locations may be different than the general direction indicatedby the configuration of the piezometric surface, The flattened ridge onthe piezometric surface in the vicinity of Orlando is caused by rechargethrough the drainage wells in the area. Figure 10 depicts the piezometric

5' 40' 35' 30 25' 20' 1 I 05 81'00' 55' 80°5so

MO•NT U

L'A KE COUNTY EXPLANATION N6"

Well equfppd wilh reording age.4above mion sea level,

~ Conlour represenlt Ihe plesomelrle surface,in feel above mion

to level, In Spltember, 1960.SArrow Indlcole direction of ground-woler flow,

:o S Contour nlterval' 5 fie

40 - - 40'SEMINOLE C U NTY

--. . ...~ClUNTY

S 35' 0 . 10 057 5 050'BApe en from U.S. eolcal I 2 4 6 9 10 mlO

K14'- 550

0_3 1-.-!073

Sury opgrphc qudrngle124,0

F u 10 Oag o c t |S OSCEOLA 042COUNTY

35 . 5 8050

12 4,000K

Figure 10. Orange County,,.Florida, showing the contours of the piezometric surface at high water condi.tions, September 1960. I

... - r7 1 1I I I I .ll ll i ir I - II i i I 1 1 I I I 1 i I - n i 1 1 '_ ..=.,.' '*x,, . ^ , ' N '' '»-.-' "

" 4L l I.XPLANATION

<»'-~l e vel, in'"111i - 451above mien iII level.

Conaour represenlis Ih pleiom rle slurfuce,in feel oboe1 moen Iga lwirl, in JulI, 1l1, Dolhid

0 hre i nterred Arrow indole, dlreslin of RA oM -wlr IowSAPOK Confour Inervo a fltef

S4d 40

\5 'o , SEMINOLE

is 0 U N Y T Y

. .--- ',... .. COU T _o f l T ,3 5 7 9

.. e 00o i ' o

e 01

36 - 3d-- ii i 4 6 il

Boe tken from U S Geological o I 2 3 4 6. I0 mil

a 24,000

Fiure 11. Orane County Florida, showin the contours of the iezometric surfa at bout normal ontons J 1961.

O S C E OL A COUNTY

8145' 354 30' 2'20' 20 l0 05' 810' 55 8O'50S

Borle token from U S ologicol 0 I 2 3 44 5 6 7 8 9 lOmilesSurvey lopogrophis quoalroago6

1124,000

Figure 11. Orange County, Florida, showing the contours of the piezometric surface at about normal conditions, July 1961.


levels in September 1960, the highest observed during the investigation.The high levels of September 1960 equaled or exceeded the highestprevious recorded levels, which occurred in the early 1930's. Figure 11,which shows the piezometric surface in July 1961, about 10 months later,represents about normal conditions.

The magnitude of fluctuations of the piezometric surface rangesfrom place to place in the county. The greatest fluctuations occur inOrlando, where more than 300 drainage wells in and around the citypermit direct and immediate recharge to the aquifer (fig. 3) and wherepumping is concentrated. Hydrographs of five artesian wells in figure 8illustrate this condition. The water level in well 833-120-3 at theOrlando Air Base varied 23 feet in 1960-61, from a high of 75 feet onSeptember 11, 1960, to a low of 52 feet on June 6, 1961, whereas thefluctuation in the other wells in the Floridan aquifer was small.

Recharge and discharge: Most of the recharge to the Floridanaquifer in Orange County is from infiltration of rain through the relativelythin semipermeable confining beds in the highlands section of the countyand through the more than 300 drainage wells in the county. A lesserquantity enters the county by underground flow from southern Lake Countyand a very small amount enters from Osceola County. The best data

available in 1961 suggest that most of the ground water in the artesianaquifer in Orange County originates within the county.

Discharge of ground water from the Floridan aquifer in OrangeCounty is by (1) outflow into northern Lake County, Seminole County,and Brevard County; (2) upward leakage into the St. Johns marsh; (3) use

within the county; and (4) spring outflow. Preliminary estimates ofthe

amount of recharge of artesian water from various sources and dischargeto various areas are given in the section on water budget.

Quality of water: The quality of the water in the Floridan aquifer

ranges greatly throughout the county, but varies little at a particular

location and depth. The total dissolved solids, as estimated fromconductivity measurements, ranged from 60 ppm in water from well

843-131-1 in the northwestern part of the county to 1,810 ppm in water

from well 829-056-1 in the eastern part of the county.

Figure 12 shows that in the western part of the county most of

the water in the Floridan aquifer is relatively low in mineral content,

and the dissolved solids are less than 150 ppm. The mineral content

of the water increases toward the eastern part of the county, and the

,6ll- T" -- I- - K.... OT-'i'a oS--'r"T-- i*r-T- *7T"-'F-"-7'T-r-"'T'T-T~'T T-T~iT~T -F-i-TT-rT--r'I""" -r-r-T--1-r-r"--'-l-r-"i-i" i , '

-3-,1 -ki P,.AN4TION4 P 1 U T IOLVTP 0LiO IN PPM

-.. T AKE C. OUy 0 Laos than 100SRANGE CCINTY !1Il io 500

"Q 0 b 4,01 tao < B° OO0 501 ta b0040 0 O IQ 1000 * . 4W.

0 Q * Orelter than 1000

S! o ~

4d - 40'0 S SEMINOLE

' La. - ORANGE 0 o0 , 0 R r

O U N T Y. . ' -" ° ° .. 'J " " ".'

-o- o o ooo * \ , -, o

000 S -U N T

0 G)0 0 0 00 -0

0 RANGE O UNTY4000 0

g e 1 O 3Cu 30F 2 20' f 10d 05o t 55w 80'i'Bao tken from U. S. Geological a I 2 3 4 ' 6 B 9 M0 mil0 l

Survey topographic quadrangles1124,000

Figure 12. Orange County, Florida, showing general range of dissolved solids of the water in wells in the Floridan aquifer.

INFORMATION CIRCULAR NO. 41 41.

dissolved solids exceed 1,000 ppm in the flowing wells along the St.Johns River. The high mineral content of artesian water in the easternpart of the county is probably due to incomplete flushing of saline waterthat entered the aquifer when the sea last covered Florida.

Figure 13 shows the principal mineral constituents in water fromselected wells in the Floridan aquifer in Orange County. The totalalkalinity (carbonate plus bicarbonate) is reported as carbonate. Car-bonate is present in natural water when the pH value exceeds 8.2. Someof the artesian water in Orange County contains small amounts of carbon-ate, but most of the alkalinity is due to bicarbonate.

The composition of water from well 843-136-1 in northwesternOrange County and from well 832-058-1 in eastern Orange County (fig.13)indicates that artesian water in western OrangeCounty is high in calciumcarbonate whereas the highly mineralized water in the eastern part of thecounty is high in sodium chloride.

Except for high hardness, most water from the Floridan aquiferin western and central Orange County is of good chemical quality.However, water from flowing wells to the east along the St. Johns Riveris very hard and contains large amounts of sodium, sulfate, and chloride.West of longitude 81003' the hardness ranged from 48 to 335 ppm andaveraged 153 ppm. The water from well 832-058-1, near the east edgeof Orange County, had a hardness of 590 ppm, contained 354 ppm of

sodium, 250 ppm of sulfate, and 630 ppm of chloride on July 3, 1957.Water from the same well had a hardness of 580 ppm and contained 640ppm of chloride on October 24, 1960. Hydrogen sulfide gas is generallypresent in water from the flowing wells, and can be detected by thecharacteristic odor and taste. Hydrogen sulfide can be eliminated byaeration.

PUMPING TEST

The ability of an aquifer to transmit water is referred to as thecoefficient of transmissibility (T); defined as the quantity of water,in gallons per day, that will move through a vertical section of theaquifer 1 foot wide and extending the full saturated height of the aquifer,

under a unit hydrologic gradient at the prevailing temperature of thewater (Theis, 1938, p. 892). A measure of the capacity of the aquifer

to store water is referred to as the coefficient of storage (S); definedas' the volume of water released from or taken into storage per unit


Well number Dissolved solids

o E ECL 9 - 70 8

0 0 0 , M 1 0 1 04a, 0 W c <a, Co t oD € OD C00 OD OD -

100- - 00

90 - -: '" 90*0 .. • " , . .0

S.0 -- , \ -. . -. 8080 -- .

S70 -C 3 70

0 . .- -

3 , "Ittio 1o 0

Floridan aquifer in Orange County, Florida.

060 60

§50 - - 50Qo __ _ . * :* - -- ---

40 - "" . ..... 40

Mg ' - - ---. --"

30 -- i " 30

20 - c C \ 20

10 -- --- -10

------------------------------- 0,

Figure 13. Composition of mineral content of water from selected wells in theFloriden aquifer in Orange County, Florida.


surface area of the aquifer per unit change in head normal to that surface.The leakage coefficient (P/m) is a measure of the ability of the confiningbeds above and below the aquifer to transmit water to the main producingzone. It is defined as the quantity of water that moves through a unitarea of the confining bed with a head difference across.the bed of unity.

The above coefficients of an aquifer can be determined from-ob-servation wells at a known distance from a well being pumped at aconstant rate by analyzing the resulting changes in water level.

A. pumping test to determine the coefficients of the Floridanaquifer was made in Orlando on February 17, 1961,. A 12-inch drainagewell on Lake Davis (841-122-4) was pumped for 11 hours at a rate of1,100 gpm and changes in water levels were recorded in four nearbywell s.

Background data collected before and after the test were usedto eliminate from the drawcown curves extraneous effects, such asnatural fluctuations of the water levels not related to the pumping.The corrected drawdown data (s) were plotted versus time (t) sincepumping began, divided by the square of the distance (r) from the pumpedwell to the observation well (s versus t/r2 ). The resulting curves werecompared with a family of leaky aquifer type curves developed by H. H.Cooper, Jr. (U.S. Geological Survey, Tallahassee, Florida). This familyof curves is based on the equation for nonsteady flow in an infiniteleaky aquifer developed by Hantush and Jacobs (1955, p. 95-100) anddescribed by Hantush (1956, p. 702-714). The equation assumes apermeable bed overlain by less permeable beds through which water,under a constant head, ;can infiltrate to reach the aquifer. The trans-missibility and storage coefficients obtained by the leaky aquifer methodapply to the main producing zone, and the leaky coefficient applies to thesemipermeable confining beds.

The coefficients and other pertinent data for the Orlando: test areshown in table 6. The range in, determined values reflects in part thenonhomogeneous and anisotropic conditions of the limestone aquifer.

This test indicates the aquifer has approximately the following coef-

ficients: transmissibility 500,000, storage 0.001, and leakage 0.1. Atransmissibility of 500,000 gpd/ft indicates a very productive aquifer.


Table 6. Results of Pumping Well 831-122-4, Orlando, Florida, February 17, 1961

Casing Distance to Transmis- MaximumObservation Depth Depth observation sibility Leakage drawdownwell number (feet) (feet) well (feet) (gpd/ft) Storage (gpd/ft /ft ) (feet)

831-122-15 350 88 750 455,000 0.00071 0.131 2.90

831-121-6 335 115 950 440,000 .0031 .312 .66

831-121-7 428 315 1,900 745,000 .00083 .074 .26

831-122-18 435 114 3,900 745,000 .00083 .049 .14

WATER BUDGET

The water available for use by man is that stored in surface orunderground reservoirs. If the water in these reservoirs is not usedby man, it eventually leaves the reservoir in which it is stored andmoves to another part of the hydrologic cycle. Over long-term climaticcycles the amount of water leaving an area must balance the amountentering it. If the amounts of water entering and leaving an area areout of balance, a change in the amount of water in storage occurs. Anaccounting of the amounts of water entering and leaving an area andrelated changes in storage is termed a water budget. An approximatewater budget for Orange County based upon general information presentlyavailable follows. Additional investigation will result in refining thevarious figures and they are presentedonly to show the relative magnitude.

Rainfall within Orange County averages about 2,500 mgd. Surface-water inflow averages about 140 mgd and ground-water inflow, mostlywithin the Floridan aquifer, averages about 40 mgd.

Water lost by evapotranspiration is estimated to average about1,750 mgd, surface runoff from the county averages about 790 mgd, andabout 140 mgd is lost by underground flow to Brevard, Lake, and Seminolecounties.

An average of 814 mgd of water from sources outside the countyflows along the eastern border of the county in the St. Johns River.


USE OF WATER

Use of ground water in Orange County is estimated tohave averaged

about 65 mgd in 1960. Of this total, about 17 mgd were pumped by the

Orlando Utilities Commission to users in and around Orlando, including

the Martin Company; about 9 mgd were pumped by the city .of Cocoa from

their well field in Orange County, about 7 mgd were used by privately

supplied industry, mostly for citrus processing and packing;.4 mgd were

pumped by private water companies in the Orlando area; about 3 mgd

'were used for irrigation; and an estimated 25 mgd were used by com-

munities and private individuals outside of the Orlando area.

Use of surface water is estimated to average about 45 mgd. About

30 mgd is used for irrigating citrus trees and about 15 mgd is used for

irrigating row crops mostly in the Zellwood muckland area north of Lake

Apopka.

INFORMATION CIRCULAR.N0.41; 47

REFERENCES

Black, A. P.

1951 (and Brown, Eugene) Chemical character of Florida's waters:

Florida State Board Cons., Div. Water Survey and Research Paper 6.

Brown, D. W.

1957 (and Kenner, W. E., and Brown, Eugene) Interim report on the water

resources of- Brevard -County, Florida: Florida Geol. Survey Inf.

Circ. 11-.

1962 (and Kenner, W. E., Crooks, J. W., and Foster, J. B.) Water resources

of Brevard County, Florida: Florida Geol. Survey Rept. Inv. 28.

Brown, Eugene (see Black, A. P.; Brown, D. W.)

Cole, W. S.

1941 Stratigraphic and paleontologic studies of wells in Florida: Florida

Geol. Survey Bull. 19.

1945 Stratigraphic and paleon'tologic studies oflwells in Florida - no. 4:

Florida Geol. Survey Bull. 28.

Collins, .W. D.

1928 (and Howard, C. S.) Chemical character of waters in Florida: U.-S.

Geol. Survey Water-Supply Paper 596-G.

Cooke, C. W.

1939 Scenery of Florida: Florida Geol. Survey Bull. 17..

1945 Geology of Florida: Florida Geol. Survey Bull. 29.

Cooper, H. H., Jr. (see Stringfield, V. T.)

Crooks, J. W. (see Brown, D. W.)

Fenneman, N. M.

1938 Physiography of eastern United States: New York, McGraw-Hill

Book Co., Inc.

Ferguson, G. E. (see Parker-, G..G.)-. . .


Florida State Board of Health

1961 Some physical and chemical characteristics of selected Florida

waters: June 1960.

Foster, J. B. (see Brown, D. W.)

Gunter, Herman (also see Sellards, E. H.)

1931 (and Ponton, G. M.) Need for conservation and protection of our

water supply with special reference to waters from the Ocala lime-

stone: Florida Geol. Survey 21st and 22d Ann. Rept.

Hantush, M. C.

1955 (and Jacob, C. E.) Nonsteady radical flow in an infinite leaky dquifer:

Am. Geophys. Union Trans., v. 36, no. 1, p. 95-100.

1956 Analysis of data from pumping tests in leaky aquifers: Am. Geophys.

Union Trans., v. 37, p. 702-714.

Hem, J. D.

1959 Study and interpretation of the chemical characteristics of natural

water: U. S. Geol. Survey Water-Supply Paper 1473.

Howard, C. S. (see Collins, W. D.)

Jacob, C. E. (see Hantush, M. C.)

Kenner, W. E. (see Brown, D. W.)

Love, S. K. (see Parker, G. G.)

MacNeil, F. S.

1950 Pleistocene shorelines in Florida and Georgia: U. S. Geol. Survey

Prof. Paper 221-F.

Matson, G. C.1913 (and Sanford, Samuel) Geology and ground waters of Florida: U. S.

Geol. Survey Water-Supply Paper 319.

Meinzer, O.E.1923 The occurrence of ground water in the United States, with a dis-

cussion of principles: U. S. Geol. Survey Water-Supply Paper 489.


Parker, G. G.

1955 (and Ferguson, G. E., Love, S. K., and others) Water resources of

southeastern Florida: U.S. Geol. Survey Water-Supply Paper 1255.

Ponton, G. M. (see Gunter, Herman)

Puri, H. S.

1953 Contribution to the study of the Miocene of the Florida Panhandle:

Florida Geol. Survey Bull. 36.

Rainwater, F. H.

1960 (and Thatcher, L. L.) Methods for collection and analysis of water

samples: U. S. Geol. Survey Water-Supply Paper 1454.

Reitz, H. J. (see Wander, 1. W-)

Sanford, Samuel (see Matson, G. C.)

Sellards, E. H.

1908 A preliminary report on the underground water supply of central

Florida: Florida Geol. Survey Bull. 1.

1913 (andGunter,Herman) The artesian water supply of eastern and southernFlorida: Florida Geol. Survey 5th Ann. Rept.

Stringfield, V. T.

1935 The piezometric surface of artesian water in the Florida Peninsula:

Am. Geophys. Union Trans., 16th Ann. Mtg., Pt. 2, p. 524-529.

1936 Artesian water in the Florida Peninsula: U. S. Geol. Survey Water-

Supply Paper 773-C.

1950 (and Cooper, H. H., Jr.) Ground water in Florida: Florida Geol.

Survey Inf. Circ. 3.

Thatcher, L. L. (see Rainwater, F. H.)

Theis, C. V.

1938 The significance and nature of the cone of depression in ground-

water bodies: Econ. Geology, v. 33, no. 8.

U. S. Geological Survey

1943 Progress report on hydrologic studies of lake sources of municipal

water supplies of Orlando, Florida: Open-file rept.


U. S. Weather Bureau

1960 Climatological data, Florida, annual summary, 1960: v. 64, no. 13.

Unklesbay, A. G.

1944 Ground water conditions in Orlando and vicinity, Florida: Florida

Geol. Survey Rept. Inv. 5.

Ver.-on, R. O.

1951 Geology of Citrus and Levy counties, Florida: Florida Geol. Survey

Bull. 33.

Wander, 1. W.

1951 (and Reitz, H.J.) The chemical composition of irrigation water used in

Florida citrus groves: Univ.of Florida Agr. Experiment Station Bull.408.

White, W. A.

1958 Some geomorphic features of central peninsular Florida: Florida

Geol. Survey Bull. 41.

-FLORIDA-GEOLOGICAL-SURVEY

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