Ona

Tampa

Ocala

Venus

DeLand

Venice

Bartow

Ruskin

Brandon

Parrish

Palatka

Tavares

Orlando

Seville

Placida

Dunedin

Bronson

Gardner

Arcadia

Sebring

Sarasota

Lorraine

Bushnell

Oklawaha

Leesburg

Lakeland

Mulberry

Pineland

Suwannee

Palmdale

La Belle

Basinger

Wauchula

Englewood

Bradenton

Chiefland

Inverness

Homosassa

Kissimmee

Polk City

Davenport

Dade City

Avon Park

Fort Myers

Clearwater

Cross City

Fort McCoy

Rock Ridge

Plant City

Fort Ogden

Frostproof

Lake Wales

Fort Meade

Cape

Coral

Punta Gorda

Myakka

Head

Myakka City

Saint Cloud

Lake Alfred

Citrus Park

Zephyrhills

San Antonio

Brooksville

Port Richey

Gainesville

Lake Placid

Winter Haven

Daytona Beach

Fort Lonesome

Crystal River

Tarpon Springs

Port Charlotte

St. Petersburg

Altamonte Springs

STARKEY

DUNEDIN

CROSS BAR

RANCH

BELLEAIR

CYPRESS CREEK

MORRIS

BRIDGE

SOUTH CENTRAL

NW HILLSBOROUGH

DISPERSED

EAST

LAKE

VERNA

ELDRIDGE

WILDE

NORTH

PASCO

ODESSA

COSME

SOUTH PASCO

LAKELAND

SECTION 21

PINE ISLAND

SOUND

CHAR LO TTE

HA

RB

O

R

CALOOSAHATCHEE

RIVER

LAKE

OKEECHOBEE

Shell Creek

Prairie

Creek

Horse

Creek

Peace River

Big Slough Canal

Deer Prairie

Creek

Myakka River

LAKE

ISTOKPOGA

Lake

Jackson

Lake

Placid

Lake June

in Winter

Braden River

Manatee

River

Little Manatee River

S. Prong

Reedy

Lake

Lake

Livingston

Lake

Clinch

Crooked

Lake Buffum

Lake

Peace River

Lake

Arbuckle

Lake

Wechyokapka

Lake

Rosalie

Tiger

Lake

LAKE

KISSIMMEE

Lake Marian

TAMPA

BAY

HILLSBOROUGH

BAY

OLD TAMPA

BAY

Alafia

River

N. Prong

Lake

Hancock

Lake

Garfield

Lake

Pierce

Lake

Jackson

Cypress

Lake

Lake

Gentry

Alligator

Lake

Lake

Preston East Lake

Tohopekaliga

Lake

Hart

Lake Tohopekaliga

Lake

Conway

Lake

Hamilton

Lake

Marion

Lake

Juliana

Lake

Mattie

Lake

Parker Lake

Thonoiosassa

Blackwater

Creek

River

Hillsborough

Withlacoochee

River

Lake

Tarpon

An c l o te

River

Pithlachascoiee

River

Crews

Lake

Lake

Monroe

Lake

Jessup

Lake

Harney

LAKE

APOPKA

LAKE

HARRIS

Lake

Dora

Lake

Griffin

Lake Eustis

Lake

Dorr

Lake

Norris

Lake

Weir

Lake

Panasoffkee

Wekiva

River

Lake

Louisa

Lake

Minnehaha

TSALA

APOPKA

LAKE

Crystal River

Springs Group

LAKE

GEORGE

Lake

Woodruff

Lake

Disston

Lake

Kerr

ST. JOHNS RIVER

Oklawaha River

Orange

Lake

Lake

Stafford

CRESCENT

LAKE

Lochloosa

Lake

Newmans

Lake

ST. JOHNS RIVER

Wekiva

River

River

Waccasassa

G U L F

O F

M

E X

I

C

O

ATLANTIC OCEAN

Lithia

Springs

Sulphur

Springs

Rainbow

Springs

Homosassa

Springs

WeekiWachee

Springs

Warm

Mineral

Springs

Chassahowitzka

Springs

Crystal

Springs

Crystal River Springs

L E E

P O L K

L A K E

D I X I E

TAYLOR

H E N D R Y

G L A D E S

O R A N G E

C I T R U S

M A R I O N

P U T N A M

D E S O T O

O S C E O L A

V O L U S I A

F L A G L E R

A L A C H U A

S A R A S O T A

S E M I N O L E

S T J O H N S

C H A R L O T T E

H I G H L A N D S

G I L C H R I S T

O K E E C H O B E E

P A S C O

H A R D E E

S U M T E R

M A N A T E E

P I N E L L A S

H E R N A N D O

H I L L S B O R O U G H

L E V Y

40

30

50

10

20

70

80

90

100

110

120

70

60

10

20

30

10

60

20

80

30

20

70

40

50

50

50

50

70

60

80

90

70

30

10

40

40

50

60

70

50

5

6

0

0

70

50

60

70

80

90

4

3

5

3

1

6 4

5

8

5

8

7

9

6

5

6

1

4 5

2

3

2

2

2

8 7

9

8

2

3 3

4 4

0

8

2

4 5

4 5

5

3

7 8

9 8

8

9

6

6 9 9

7 6 6 6

3

1

7 8

9

1

20

14

29

19

45

48

25

29

22

15

23

21

53

20 52

52

45 52

53 45

54 54

50

45 47 25

45

16

45

15

46

44

11

12

43

42 44 47

42 43

41 45

26

17

39 45 46

32 44 36

54 36

38 19 48 41 47

32 52 17

38 45

40 49 46

16

54 13

45

43

43 15 46

48

19 39 51 46

41 12

26 33

47 36 53

47

52

57

58

38 49 47 41 28

19 65

43 21

39

12 48

18 50 12 55 39 49

33 40 67 34

41 66 40

71

53 17 16

20

60 55 21

78 41

82 77

59 79 45

78 50

79 39 44 20

81 61 34

75 39 87

41 74 49

50

63 35

50

51 85

73 39

66 86

72

51 70 90 95 82 49 54 99

45

67 87 32

59 65

35 36 35

67 70

74 46

91

78 44 43

40 37 56

46 62

40

49

61 42

52 50

72

69

43

59 57 48

82

44

83

46 63

43

45

73

45 48

48

41

51

47 50

51

49

50

65

79

44

19 49

16

52 46

44

85

82

22

82

63

39

37

45

11

11

33 15

14

12 37 14 18 26

41 25

62

41

60 58

60 68 27 54 72 75 71 73

87 32

68 74 68

70

40 90

65 45 45 31 63 37 82 73

79

41

68 62

75

51 62 61

97

47

87 23

29

24

45 47

11

49

22

15 40

94

29 55 71 54 46 88

46

32 34

29

21

28

29

20 99 99

24

48

38

18 29 39

99

91

94

16 23

84

91 25

23 82

63 85

20

10 12 21

59 98

17

17 80

18 21 55

68 12

17 45 11

14

77

39 78

62

13 35 23

36 15 37 59

24

97

23

13

93

11

78

11 89

28 78

87

83

43 86 14

13

17

76 77

20

49

19

12

45 88

15

20 62 74

38 82

62 15

70

15

84

15 35

27

18

55 50

20

33 58 36 21

65

48

24

30 34 23

49 49 44

47 71

50

50 24 51

34 42 50

29 39 48

35 36 29

33 50

34 21

37 44

24 42 50

24

48

48

29 36

46

52

46

100

115

104

110

117

109

105

124

125

104 126

127

127

128

118

123

113

100

117

100

108

104

100

8

6

7

9

31

30

72

54

58

35

40

52

19

60

57

59

49

31

17

12 11

29 42

18

81°

81°

82°

82°

83°

83°

84°

84°

29°

29°

28°

28°

27°

27°

SCALE 1:500,000

MILES

KILOMETERS

5 0 5 10 15 20

5 0 5 10 15 20

A

T LA

NT IC OCEAN

G U L F O F M E X I C O

STUDY AREA

MAP AREA

ALABAMA GEORGIA

FLORIDA

U.S. DEPARTMENT OF THE INTERIOR

U.S. GEOLOGICAL SURVEY

Prepared in cooperation with the

SOUTHWEST FLORIDA WATER MANAGEMENT DISTRICT

Scientific Investigations Map 3148

Ortiz, A.G., 2011, Potentiometric surface of the Upper

Floridan aquifer, west-central Florida, September 2010

POTENTIOMETRIC SURFACE OF THE UPPER FLORIDAN AQUIFER,

WEST-CENTRAL FLORIDA, SEPTEMBER 2010

By A.G. Ortiz

Base from Southwest Florida Water Management District digital data, 1992,

State Plane Florida East projection, NAD83

Copies of this map can be purchased from:

U.S. Geological Survey

Branch of Information Services

Box 25286

Denver, Colorodo 80225-0286

Figure 1. Change in potentiometric surface of the Upper Floridan aquifer from September 2009 to

September 2010 in west-central Florida. Positive values indicate an increase in water-level altitudes.

Negative values indicate a decrease in water-level altitudes.

HYDROLOGIC CONDITIONS IN WEST-CENTRAL FLORIDA

The Floridan aquifer system consists of the Upper and Lower Floridan aquifers separated

by the middle confining unit. The middle confining unit and the Lower Floridan aquifer in

west-central Florida generally contain highly mineralized water. The water-bearing units

containing fresh water are herein referred to as the Upper Floridan aquifer. The Upper

Floridan aquifer is the principal source of water in the Southwest Florida Water Management

District and is used for major public supply, domestic use, irrigation, and brackish water

desalination in coastal communities (Southwest Florida Water Management District, 2000).

This map report shows the potentiometric surface of the Upper Floridan aquifer measured

in September 2010. The potentiometric surface is an imaginary surface connecting points

of equal altitude to which water will rise in tightly-cased wells that tap a confined aquifer

system (Lohman, 1979). This map represents water-level conditions near the end of the

wet season, when groundwater levels usually are at an annual high and withdrawals for

agricultural use typically are low. The cumulative average rainfall of 53.17 inches for

west-central Florida (from October 2009 through September 2010) was 0.41 inches above the

historical cumulative average of 52.76 inches (Southwest Florida Water Management

District, 2010). Historical cumulative averages are calculated from regional rainfall summary

reports (1915 to most recent complete calendar year) and are updated monthly by the

Southwest Florida Water Management District.

This report, prepared by the U.S. Geological Survey in cooperation with the Southwest

Florida Water Management District, is part of a semi-annual series of Upper Floridan

aquifer potentiometric-surface map reports for west-central Florida. Potentiometricsurface maps have been prepared for January 1964, May 1969, May 1971, May 1973, May 1974,

and for each May and September since 1975. Water-level data are collected in May and

September each year to show the approximate annual low and high water-level conditions,

respectively.

Most of the water-level data for this map were collected by the U.S. Geological Survey during

the period September 13-17, 2010. Supplemental water-level data were collected by other

agencies and companies. Most water-level measurements were made during a 5-day period;

therefore, measurements do not represent a "snapshot" of conditions at a specific time,

nor do they necessarily coincide with the seasonal low water-level condition.

WATER-LEVEL CHANGES

Water levels in about 61 percent of the wells measured in September 2010 were higher than the

September 2009 water levels (Ortiz, 2010a). Data from 402 wells indicate the September 2010 water

levels ranged from about 9 feet below to about 6 feet above the September 2009 water levels (fig. 1).

The largest water level increase occurred in north-central Pasco County. The largest water

level declines occurred in south-central Pasco County and north-central Manatee County (fig. 1).

Water levels in about 83 percent of the wells measured in September 2010 were higher than the

May 2010 water levels (Ortiz, 2010b). Data from 413 wells indicate the September 2010 water

levels ranged from about 5 feet below to 23 feet above the May 2010 water levels. The largest

water level decline was in northwest Pasco County and the largest rise in water levels was in

east-central Manatee County.

ACKNOWLEDGMENTS

The author thanks Tampa Bay Water and CF Industries for their assistance with the collection of

data used to prepare this report.

SELECTED REFERENCES

Lohman, S. W., 1979, Ground-water hydraulics: U. S. Geological Survey Professional Paper 708, 72 p.

Ortiz, A. G., 2010a, Potentiometric surface of the Upper Floridan aquifer, west-central Florida,

September 2009: U.S. Geological Survey Scientific Investigations Map 3117, 1 sheet.

Ortiz, A. G., 2010b, Potentiometric surface of the Upper Floridan aquifer, west-central Florida,

May 2010: U.S. Geological Survey Scientific Investigations Map 3139, 1 sheet.

Southwest Florida Water Management District, 2000, Aquifer characteristics within the Southwest

Florida Water Management District: Broooksville, FL, 123 p.

Southwest Florida Water Management District, 2010, Hydrologic conditions for the month of September

2010: Broooksville, FL, 84 p.

EXPLANATION

MUNICIPAL WELL FIELD

POTENTIOMETRIC CONTOUR -- Shows altitude at which water would have stood in tightly cased wells. Contour interval is 10 feet.

National Geodetic Vertical Datum (NGVD) of 1929. Hachures indicate depressions. Dashed where approximately located.

BOUNDARY OF SOUTHWEST FLORIDA WATER MANAGEMENT DISTRICT

OBSERVATION WELL -- Number is altitude of water level in feet above or below NGVD of 1929.

SPRING

CITY OR TOWN

OBSERVATION WELL -- Number is altitude of water level in feet above or below NGVD of 1929.

Bold number indicates water levels corrected for salinity.

VERNA

20

16

21

>= 5.00

0 to 4.99

<0 to -4.99

-5.00 to -9.99

EXPLANATION

Change in the potentiometric

surface, in feet

(Positive values indicate an

increase in water-level altitudes)