The Suwannee River flows through an area of northcentral Florida where ground water has elevated nitrate 

concentrations. A study was conducted to determine 

how springs and other ground-water inflow affect the 

quantity and quality of water in the Suwannee River. The 

study was done on a 33-mile (mi) reach of the lower 

Suwannee River from just downstream of Dowling 

Park, Fla., to Branford, Fla. (fig. 1). Water samples for 

nitrate concentrations (dissolved nitrite plus nitrate as 

nitrogen) and discharge data were collected at 11 springs 

and 3 river sites during the 3-day period in July 1995 

during base flow in the river.

In the study reach, all inflow to the river is derived 

from ground water. Measured springs and other groundwater inflow, such as unmeasured springs and upward 

diffuse leakage through the riverbed, increased the river 

discharge 47 percent over the 33-mi reach. The 11 measured springs contributed 41 percent of the increased 

discharge and other ground-water inflow contributed 

the remaining 59 percent. River nitrate loads increased 

downstream from 2,300 to 6,000 kilograms per day 

(kg/d), an increase of 160 percent in the 33-mi study 

reach. Measured springs contributed 46 percent of this 

increase and other ground-water inflow contributed the 

remaining 54 percent.

The study reach was divided at Luraville, Fla., into 

an 11-mi upper segment and a 22-mi lower segment to 

determine whether the ground-water inflows and nitrate 

concentrations were uniform throughout the entire 

study reach (fig. 1). The two segments were dissimilar. 

The amount of water added to the river by measured 

springs more than tripled from the upper to the lower 

segment. Even though the median nitrate concentration 

for the three springs in the upper segment (1.7 milligrams 

per liter (mg/L)) was similar to the median for the eight 

springs in the lower segment (1.8 mg/L), nitrate concentrations in the river almost doubled from 0.46 to 

0.83 mg/L in the lower segment. Only 11 percent of the 

increase in nitrate load for the study reach occurred in 

the upper segment; the remaining 89 percent occurred in 

the lower segment. Measured springs were the major 

source of nitrate load in the upper reach and other 

ground-water inflow was the major source in the lower 

segment.

Differences in nitrate loads between the upper and 

lower river segments are probably controlled by such 

factors as differences in the magnitude of the spring 

discharges, the size and location of spring basins, and 

the hydrologic characteristics of ground water in the 

study area.

FLORIDA

SOUTH

CAROLINA

ALABAMA GEORGIA

Location of the

area of study and the

Suwannee River Basin

upstream of

Branford, Florida

Area of Study

Suwannee

River

Basin

Spring Contributions to Water Quantity and

Nitrate Loads in the Suwannee River

during Base Flow in July 1995

By John R. Pittman, Hilda H. Hatzell, and Edward T. Oaksford

Summary
2

Steinhatchee River

Su

wannee

River

Suwannee

River

Fenholloway

River

Santa Fe River

SUWANNEE

COUNTY

GILCHRIST

COUNTY COLUMBIA

COUNTY

TAYLOR

COUNTY

MADISON

COUNTY

Dowling

Park

Luraville

Live

Oak

LAFAYETTE

COUNTY

10 75

90

27

27

129

129

129

51

247

349

53

250

83°15′ 83°00′

30°15′

30°00′

82°45′

Shirley

Spring

Charles

Springs

Royal Spring Convict

Spring

Running

Springs

Telford

Springs

Little River

Springs

Blue

Spring

Troy Spring

Mearson Spring

Ruth Spring

Branford

51

19

Ellaville

Location of Ellaville

and the area of study

within the Suwannee

River Basin

0

0

5 MILES

5 KILOMETERS

DIRECTION OF

SURFACE-WATER FLOW

SURFACE-WATER SAMPLING SITE

SPRING

EXPLANATION

Figure 1. Location of 11 springs and 3 surface-water sampling sites along the Suwannee River 

in north-central Florida.

Introduction

The Suwannee River, important historically and recreationally, is of great interest to the State of Florida and has been 

designated as an “Outstanding Florida Water.” Of particular 

interest to water-resource agencies is the increase of nitrogen in 

this valuable river, especially during periods of base flow.

For 20 years (1971-91), nitrate concentrations in the 

Suwannee River near Branford, Fla., increased at a rate of 

0.02 mg/L per year; the median nitrate concentration for that 

period was 0.5 mg/L (Ham and Hatzell, 1996). Possible 

sources for nitrate in ground water in the study area are septic 

tanks, synthetic fertilizers, and animal waste (Andrews, 1994). 

The Suwannee River recharges and receives discharge 

from the Upper Floridan aquifer, the primary source of public 

and private water supply in the Suwannee River Basin and the 

surrounding areas (fig. 1). In the northwestern part of the 

basin in Georgia, direct surface runoff is a significant source 

of inflow to the basin. In the northeastern and southern parts 

of the basin, inflow to the river is predominantly from numerous springs and upward diffuse leakage of ground water 

through the riverbed (riverbed leakage). 

Base flow in rivers occurs during natural conditions when 

ground-water discharge to the river is the primary source of 

flow. Ground-water influence on water quality in the river is 

more pronounced during base flow and in the river reaches 

having the greatest number of springs and the least tributary 

inflow (Hull and others, 1981). The Suwannee River directly 

recharges ground water in the Upper Floridan aquifer when 

river levels are above the adjacent ground-water levels. The 

pattern reverses during periods of base flow, when the groundwater levels are above the river water levels and ground-water 
3

J J F M A M J A S O N D

1995

5,000

10,000

15,000

20,000

25,000

0

DISCHARGE, IN

CUBIC FEET PER SECOND

ELLAVILLE

Sampling

Interval

BRANFORD

discharges to the river through numerous springs and from 

riverbed leakage. These gains and losses from the river can be 

simultaneous in adjoining parts of the river as ground-water 

discharges to the river in one part while the river recharges the 

ground water in another part (Crane, 1986). 

The median nitrate concentration for ground water in 

north-central Florida is low (0.01 mg/L nitrate as nitrogen; 

Katz, 1992). However, mean nitrate concentrations ranged 

from less than 0.5 to greater than 4 mg/L in ground water in 

the vicinity of the Suwannee River between Ellaville, Fla., 

and Branford, Fla. (Ceryak and Hornsby, 1996). These 

elevated nitrate concentrations increase the likelihood that 

ground-water inflow from springs and riverbed leakage can 

increase nitrate concentrations and loads in the lower 

Suwannee River. 

Study Design

A study was conducted in July 1995 to determine how 

springs and other ground-water inflow affect the quantity and 

quality of water in the Suwannee River during base flow. 

The study area was a 33-mi reach of the lower Suwannee 

River, extending from 1.2 mi south of the bridge at State 

Road 250 near Dowling Park, Fla., downstream to the bridge 

at U.S. Highway 27 at Branford, Fla. (fig. 1). This river reach 

was selected because all inflow to the river is from ground 

water. The study reach includes Troy Spring, which is a first 

magnitude spring, and about 25 other named springs. 

Eleven springs along the reach were selected for discharge 

measurements and water-quality sampling (fig. 1). Criteria 

for spring selection were based on a variety of spring 

properties, such as the amount of discharge, previous nitrate 

concentrations, size of the spring run, location along the 

reach, and land uses in the vicinity of the orifice. Spring 

discharge measurements were made by standard U.S. Geological Survey methods for wadeable channels (Buchanan 

and Somers, 1969). Three river discharge measurement and 

sampling sites were also selected (fig. 1). River discharge 

measurements were made with a broad band acoustic Doppler 

current profiler (Simpson and Oltmann, 1993).

Contributions to river discharge from measured springs 

and other ground-water inflow (unmeasured springs and 

upward diffuse leakage through the riverbed) can be 

determined by calculating the gain in river discharge within 

the reach when two conditions are met. First, there should be 

no surface-water inflow to the study reach from tributaries. 

The reach of the Suwannee River from just downstream of 

Dowling Park to Branford was selected because of the lack of 

surface-water tributaries as well as the high density of springs. 

Second, the river discharge in the reach should be nearly 

stable throughout the measurement period. Near-stable flow 

conditions (less than 10 percent change in river discharge) 

usually occur during base flow when sustained periods of little 

or no precipitation occur in the drainage basin. 

Hydrographs of the Suwannee River at Ellaville and 

Branford indicated that the river was at base flow during late 

July 1995 (fig. 2). The stream gaging station at Ellaville (station 

02319500) is 17 river miles upstream from the beginning of 

the study reach. The station at Branford (station 02320500) is at 

the downstream end of the study reach.

Figure 2. Hydrographs of Suwannee River at Ellaville and Branford, Fla.
4

The 33-mi study reach was divided 

into an 11-mi upper (upstream) segment 

and a 22-mi lower (downstream) segment 

to determine whether the measured springs 

and other ground-water inflows and nitrate 

contributions were relatively constant in 

each segment or if one segment provided 

more inflow and nitrate per river mile than 

the other. River and spring discharge 

measurements were made and waterquality samples were collected sequentially 

during July 25-27, 1995, beginning at the 

upstream site near Dowling Park and 

ending at the most downstream site at 

Branford, as follows:

After all water-quality sampling was completed, a 

discharge measurement for the river was made at the initial site 

downstream of Dowling Park to determine whether near-stable 

flow conditions had occurred throughout the sampling period.

Spring water-quality samples were collected by lowering 

Teflon tubing directly into the spring orifices and pumping the 

sample water into sample bottles using a peristaltic pump. River 

water-quality samples were collected using a weighted bottle 

sampler. The river cross-section was divided into three 

sections of equal width and the sampling boat was 

maneuvered to the center of each section during sample 

collection. One subsample of river water was collected in 

each of the three sections of the channel and the three 

subsamples were composited prior to filling the sample 

containers. Water temperature, pH, specific conductance, and 

dissolved oxygen were measured onsite. Water samples were 

analyzed for nutrients and major constituents. In this report, 

the term nitrate refers to dissolved nitrite plus nitrate nitrogen.

Table 1. Discharge, nitrate concentrations, and nitrate loads contributed to the 

Suwannee River during July 25-27, 1995

[ft3/s, cubic feet per second; mg/L, milligrams per liter; kg/d, kilograms per day. Values for river and 

spring locations were measured; values for other ground-water inflow were calculated]

Suwannee River near Dowling Park, Fla.

(301259083143700)

Suwannee River near Luraville, Fla.

(02320000)

Shirley Spring (301240083144200)

Charles Springs (02319900)

Telford Springs (02320003)

Running Springs (02320060)

Convict Spring (02320100)

Royal Spring (02320130)

Mearson Spring (02320240)

Troy Spring (02320050)

Ruth Spring (02320260)

Little River Springs (02320400)

Suwannee River at Branford, Fla. (02320500)

Blue Spring (02319950)

Other ground-water inflow

Other ground-water inflow

2,020

2,370

1.5

7.5

33

17

1.7

16

30

132

9.9

67

293

2,970

77

264

0.46

0.46

1.7

2.2

2.5

2.0

8.2

1.3

1.7

1.7

3.4

1.4

2.7

0.83

1.7

0.05

2,300

2,700

6

40

200

83

34

51

120

550

82

230

1,950

6,000

320

34

Location and station number River

segment

Discharge

(ft3

/s)

Nitrate

load

(kg/d)

Nitrate

concentration (mg/L)

Upper Lower

♦ River discharge was measured and 

water-quality samples were collected 

at the site near Dowling Park (station 

301259083143700).

♦ Spring discharge was measured and 

water-quality samples were collected 

at three springs (table 1) in the upper 

segment, which is between Dowling 

Park and Luraville.

♦ River discharge was measured and 

water-quality samples were collected 

at Luraville (station 02320000). 

♦ Spring discharge was measured and 

water-quality samples were collected 

at eight springs (table 1) in the lower 

segment, which is between Luraville 

and Branford.

♦ Lastly, river discharge was measured 

and water-quality samples were collected at the site at Branford (station 

02320500). 
5

The nitrate load is the mass 

of nitrate per unit of time. An 

instantaneous load, expressed in 

kilograms per day, was 

calculated by multiplying the 

nitrate concentration in the 

water sample by the instantaneous discharge, which is the 

discharge measured when the 

sample was taken. Although 

the data collected in this study 

are insufficient to determine the 

long-term variability of spring 

discharge and nitrate load, 

calculating the instantaneous 

load is helpful in understanding 

the amounts of nitrate added to 

the river from the ground water 

during the 3-day sampling 

period.

For other ground-water 

inflow from unmeasured springs 

and riverbed leakage, discharge 

and nitrate loads were 

calculated by subtracting the sum of the spring values from 

the increase in the segment. Nitrate concentrations for this 

other ground-water inflow were estimated by dividing the 

calculated load by the calculated discharge and adjusting for 

units.

River and Spring Discharge

River discharge increase over the entire 33-mi study 

reach (just downstream of Dowling Park to Branford) was 

950 cubic feet per second (ft3

/s), or about 47 percent (table 1). 

Measured springs contributed 41 percent of the increase in 

discharge, whereas other ground-water inflow contributed

the remaining 59 percent (fig. 3). River discharge increased 

350 ft3/s in the upper segment of the reach between Dowling Park and Luraville. In this 11-mi segment, 25 percent of 

the increase in river discharge was contributed by measured 

springs, whereas 75 percent was contributed by other groundwater inflow (fig. 3). River discharge increased 600 ft3/s in 

the lower segment of the reach between Luraville to Branford. In this 22-mi segment, 51 percent of the increase in 

discharge was contributed by measured springs, whereas 

49 percent was contributed by other ground-water inflow. 

Little River Springs above

Nitrate concentrations at springs 

(except for 

Convict Spring) 

were generally 

lower than those 

reported 

for ground 

water in the 

same area.

Branford, Fla.
6

The difference in segment lengths must be addressed 

to compare the increases in river discharge between the 

two segments of the study reach. One way to compare the 

amount of water entering the river in the two segments is 

to compare the amount of increase in discharge per river 

mile. This is calculated by dividing the change in river 

discharge per segment by the number of river miles in the 

segment. The increase in discharge per river mile is 32 

(ft3/s)/mi for the upper segment between Dowling Park 

and Luraville, and is 27 (ft3/s)/mi for the lower segment 

between Luraville and Branford. Even though more 

springs occur in the lower segment, the springs did not 

increase the discharge per river mile in the lower segment 

relative to the upper segment. 

Discharge in the Suwannee River at the upstream site 

downstream of Dowling Park increased about 11 percent 

during the 3-day sampling period, whereas discharge at 

Branford remained stable throughout the sampling period. 

The stable condition at Branford indicated that the increase in 

discharge at Dowling Park had not yet occurred throughout 

the entire sampling reach; thus, stable conditions existed 

during the sampling period. Because of the increase in 

discharge at the upstream site of the study reach, calculations 

of contributions from the two segments of the river reach are 

considered approximate values. The changes in river 

discharge between Dowling Park and Branford are attributed 

to discharge from the measured springs and other groundwater inflow, such as unmeasured springs and riverbed 

leakage, as well as the possible small error introduced by the 

11 percent increase in flow entering the study reach.

Figure 3. Contributions of measured springs and other ground-water inflow (unmeasured springs and riverbed leakage) to increases 

in river discharge.

SPRINGS

25% OTHER

GROUND

WATER

75%

SPRINGS

51% OTHER

GROUND

WATER

49%

SPRINGS

OTHER 41%

GROUND

WATER

59%

LOWER SEGMENT

UPPER SEGMENT

STUDY REACHSuwannee

Steinhatchee River

Su

wannee

River

River

Fenholloway

River

Santa Fe River

83°15′ 83°00′

30°15′

30°00′

82°45′

SURFACE-WATER SAMPLING SITE

SPRING

0 EXPLANATION

0

5 MILES

5 KILOMETERS

Blue

Spring

Ruth Spring

Convict

Spring

Troy Spring

Mearson Spring

SUWANNEE

COUNTY

GILCHRIST

COUNTY COLUMBIA

COUNTY

TAYLOR

COUNTY

MADISON

COUNTY

Dowling

Park

Branford

Live

Oak

LAFAYETTE

COUNTY

Royal Spring

Running

Springs

Little River

Springs

Telford

Springs

Shirley

Spring

Charles

Springs

Luraville
7

Nitrate Concentrations

Nitrate concentrations in the measured springs ranged 

from 1.3 to 8.2 mg/L (table 1; fig. 4). The highest nitrate concentration was measured at Convict Spring, a low discharge 

spring, which has a history of higher nitrate concentrations 

than other springs in the area (Hornsby and Mattson, 1997, 

p. 124). This elevated nitrate concentration may be derived 

from leachate from septic tanks at a development surrounding 

the spring, or it may be from fertilized cropland several hundred feet south of the spring (Andrews, 1994). In contrast, 

Blue Spring, a high discharge spring located within a county 

park that uses septic tanks for the groundskeeper residence 

and public restrooms, has a nitrate concentration of 1.7 mg/L. 

Nitrate concentrations at springs other than Convict Spring 

were generally lower than those reported for ground water in 

the same area (Ceryak and Hornsby, 1996, p. 22).

Nitrate concentrations at the three river sites were lower 

than nitrate concentrations at the springs (fig. 4). The nitrate 

concentration in the river was 0.46 mg/L at the upstream site 

just downstream of Dowling Park, remained unchanged at 

Luraville, and increased to 0.83 mg/L at Branford (table 1). 

Although nitrate concentrations in the river almost doubled 

from Luraville to Branford, there was little appreciable 

difference in median nitrate concentrations of springs in the 

upper and lower segments. Median nitrate concentration in the 

three springs sampled in the upper segment was 1.7 mg/L, 

whereas the median nitrate concentration in the eight springs 

sampled in the lower segment was 1.8 mg/L. 

The estimated nitrate concentrations (table 1) for other 

ground-water inflow (unmeasured springs and riverbed 

leakage) were different for the two segments. In the upper 

segment, the estimated nitrate concentration was 0.05 mg/L, 

which is much lower than that of the measured springs but of 

the same magnitude as the median nitrate as nitrogen 

concentration of 0.01 mg/L for ground water in north-central 

Florida (Katz, 1992). In contrast, the estimated nitrate 

concentration for other ground-water inflow in the lower 

segment was 2.7 mg/L, which is within the range of the 

concentrations for the measured springs (table 1).

Figure 4. Nitrate concentrations and loads in the Suwannee River and 11 springs discharging to the river reach between Dowling 

Park and Branford, Fla. (River nitrate loads are an order of magnitude larger than spring loads.)

0

7,000

1,000

2,000

3,000

4,000

5,000

6,000

NITRATE LOAD, KG/D

10

0

2

4

6

8

NITRATE

CONCENTRATIONS,

MG/L

RIVER

SITES

RIVER

SITES

0

700

100

200

300

400

500

600

NITRATE LOAD, KG/D

UPPER

SEGMENT

UPPER

SEGMENT

(springs between

Dowling Park and

Luraville, Fla.)

(springs between

Dowling Park and

Luraville, Fla.)

LOWER

SEGMENT

LOWER

SEGMENT

(springs between

Luraville and

Branford, Fla.)

(springs between

Luraville and

Branford, Fla.)

SHIRLEY

SPRING

RUNNING

SPRINGS

CONVICT

SPRING

ROYAL

SPRING

MEARSON

SPRING

TROY

SPRING

RUTH

SPRING

LITTLE

RIVER

SPRINGS

DOWLING

PARK

LURAVILLE

BRANFORD

TELFORD

SPRINGS

BLUE

SPRING

CHARLES

SPRINGS
8

Figure 5. Contributions of measured springs and other ground-water inflow (unmeasured springs and riverbed leakage) to increases 

in river nitrate load.

SPRINGS

41% OTHER

GROUND

WATER

59%

OTHER

GROUND

WATER

8%

SPRINGS

92%

SPRINGS

OTHER 46%

GROUND

WATER

54%

LOWER SEGMENT

STUDY REACHSuwannee

Steinhatchee River

Su

wannee

River

River

Fenholloway

River

Santa Fe River

83°15′

30°15′

30°00′

82°45′

SURFACE-WATER SAMPLING SITE

SPRING

0 EXPLANATION

0

5 MILES

5 KILOMETERS

SUWANNEE

COUNTY

GILCHRIST

COUNTY COLUMBIA

COUNTY

TAYLOR

COUNTY

MADISON

COUNTY

Dowling

Park

Branford

Live

Oak

LAFAYETTE

COUNTY

UPPER SEGMENT

83°00′

Ruth Spring

Convict

Spring

Blue

Spring

Troy Spring

Mearson Spring

Royal Spring

Running

Springs

Little River

Springs

Telford

Springs

Shirley

Spring

Charles

Springs

Luraville

Nitrate Loads

Nitrate loads for the springs varied nearly two orders of 

magnitude, ranging 6 kg/d at Shirley Spring to 550 kg/d at Troy 

Spring (table 1; fig. 4). A comparison of nitrate loads for the 

springs provides a different perspective than the comparison of 

nitrate concentrations in the springs. For example, Convict 

Spring had the highest nitrate concentration (8.2 mg/L), but 

because of its low discharge the nitrate load was only 34 kg/d. 

Royal Spring had the lowest nitrate concentration (1.3 mg/L), 

but because of a higher discharge had a higher load (51 kg/d) 

than Convict Spring.

River nitrate loads increased 160 percent (3,700 kg/d) in 

the entire 33-mi study reach downstream of Dowling Park to 

Branford (fig. 4). Measured springs contributed 46 percent of 

this increase and other ground-water inflow from unmeasured springs and riverbed leakage contributed the remaining 

54 percent (fig. 5). 

The nitrate loads in the upper and lower segments of the 

river reach are very different; with most of the increase in 

nitrate load occurring in the lower segment. Only 11 percent 

(400 kg/d) of the nitrate load increase occurred in the upper 

segment; the remaining 89 percent (3,300 kg/d) occurred in 

the lower segment (fig. 4). Percentages of discharge and 
9

Only 11

percent increase

in nitrate load for the

Suwannee River study reach

occurred in the upper segment;

the remaining 89 percent occurred

in the lower segment.

nitrate load coming from measured springs and other 

ground-water inflow (figs. 3 and 5) were nearly the 

same in the entire study reach. 

Measured springs, especially Blue Spring, are the 

major sources of nitrate loads in the upper segment, 

whereas other ground-water inflow is the major source 

in the lower segment (fig. 4, table 1). Although 

measured springs contributed only 25 percent of the 

river discharge in the upper segment, they contributed 

92 percent of the river nitrate load. In the lower 

segment, measured springs contributed 51 percent of 

the discharge but only 41 percent of the river nitrate 

load (figs. 3 and 5). 

Differences between the 11-mi upper and 22-mi 

lower segment are also evident in the nitrate load added 

per river mile. The upper segment added approximately 

36 (kg/d)/mi of nitrate with 33 (kg/d)/mi contributed by 

measured springs and 3 (kg/d)/mi contributed by other 

ground-water inflow. The lower segment added 

approximately 150 (kg/d)/mi of nitrate, with 

61 (kg/d)/mi contributed by measured springs and 

89 (kg/d)/mi contributed by other ground-water 

inflow.

Suwannee River above

 Branford, Fla.
10

The increase in nitrate load in the study reach is related to 

the effects of land use on ground water. Because the Upper 

Floridan aquifer is unconfined in the vicinity of the Suwannee 

River, nitrate from animal wastes, fertilizers, septic tanks, and 

other sources can readily enter the ground water by downward 

percolation through surface soils into the upper part of the 

aquifer. Numerous sinkholes associated with the karstic 

terrain in north-central Florida also provide portals for rapid 

downward movement of water. Ground water containing 

nitrate enters the river through springs and by upward diffuse 

leakage through the riverbed.

Differences in the nitrate concentrations and loads 

between the two river segments are related to several factors 

that interact with effects of land use, such as differences in 

(1) the magnitude of the spring discharge in the two segments, 

(2) the size and location of the spring basins, and (3) the 

ground-water hydrology. 

In the upper segment, only one spring (Blue Spring) 

had a discharge greater than 25 ft3/s, whereas four springs 

(Telford, Mearson, Troy, and Little River Springs) in the 

lower segment had discharges greater than 25 ft3/s (table 1). 

Of these four springs, Troy Spring (a first magnitude spring) 

accounted for 41 percent of the nitrate load from measured 

springs in the lower segment. The nitrate load contributed by 

Troy Spring is greater than the entire increase in nitrate load in 

the 11-mi upper segment (table 1; fig. 4). 

Spring basins are defined by the area contributing water 

to the discharge of the springs. The range in nitrate 

concentrations among the springs in the lower segment 

indicates that the types and intensity of land use may be more 

variable among the spring basins in the lower segment 

compared to those in the upper segment. Little information is 

available concerning the size and locations of the spring 

basins in the study area. For some of the springs in the study 

reach, a large part of the spring basin may even be on the 

opposite side of the river from the spring orifice.

Ground-water hydrologic characteristics, such as 

differences in water levels between the river and the aquifer, 

and the water-transmitting properties of the aquifer determine 

the amounts of ground water inflowing to the river from 

springs and riverbed leakage. The ground water may be 

derived from shallower or deeper parts of the Upper Floridan 

aquifer as well as from locations near or far from the river. 

Differences in the source of the ground water may contribute 

to the differences in the increase in nitrate loads between the 

two river segments. The larger percentage of increase in 

discharge, and the lower calculated nitrate concentrations 

from other ground-water inflow (unmeasured springs and 

riverbed leakage) in the upper segment compared to the lower 

segment, indicate that the contributing ground water may be 

different for the two segments. 

References

Andrews, W.J., 1994, Nitrate in ground water and spring water near 

four dairy farms in north Florida, 1990-93: U.S. Geological 

Survey Water-Resources Investigations Report 94-4162, 63 p.

Buchanan, and Somers, 1969, Discharge measurements at gaging 

stations: U.S. Geological Survey Techniques of WaterResources Investigations Book 3, Chapter A8, 65 p.

Ceryak, Ron, and Hornsby, David, 1996, Groundwater quality 

report: Live Oak, Fla., Suwannee River Water Management 

District, WR-96-02, 31 p.

Ceryak, Ron, Knapp, M.S., and Burnson, Terry, 1983, The geology 

and water resources of the upper Suwannee River Basin: Tallahassee, Florida Department of Natural Resources, Report of 

Investigations 87, 166 p.

Crane, J.J., 1986, An investigation of the geology, hydrogeology, and 

hydrochemistry of the lower Suwannee River Basin: Tallahassee, Florida Department of Natural Resources, Report of Investigations 96, 205 p.

Ham, L.K., and Hatzell, H.H., 1996, Analysis of nutrients in the 

surface waters of the Georgia-Florida Coastal Plain study unit, 

1970-91: U.S. Geological Survey Water-Resources Investigations Report 96-4037, 67 p.

Hatzell, H.H., 1995, Effects of waste-disposal practices on groundwater quality at five poultry (broiler) farms in north-central 

Florida, 1992-93: U.S. Geological Survey Water-Resources 

Investigations Report 95-4064, 35 p.

Hornsby, David, and Mattson, Rob, 1997, Surface water quality and 

biological monitoring network annual report, 1996; Live Oak, 

Fla., Suwannee River Water Management District, WR-97-03, 

200 p.

Hull, R.W., Dysart, J.E., and Mann, W.B., IV, 1981, Quality of surface water in the Suwannee River Basin, Florida, 1968 through 

December 1977: U.S. Geological Survey Water-Resources 

Investigations Report 80-110, 97 p.

Katz, B.G., 1992, Hydrochemistry of the Upper Floridan aquifer, 

Florida: U.S. Geological Survey Water-Resources Investigation 

Report 91-4196, 37 p.

Rosenau, J.C., Faulkner, G.L., Hendry, C.W., Jr., and Hull, R.W., 

1977, Springs of Florida: Tallahassee, Florida Bureau of 

Geology Bulletin 31 (revised), 461 p.

Simpson, M.R., and Oltmann, R.N., 1993, Discharge-Measurement 

system using an acoustic Doppler current profiler with applications to large rivers and estuaries: U.S. Geological Survey 

Water-Supply Paper 2395, 32 p.
11

Project Chief

Georgia-Florida Coastal Plain Study Unit

U.S. Geological Survey

227 North Bronough Street; Suite 3015

Tallahassee, FL 32301

U.S. Geological Survey

Branch of Information Services

Box 25286

Denver, CO 80225

The National Water-Quality Assessment (NAWQA) Program, conducted by 

the U.S. Geological Survey, evaluates the Nation’s ground water, rivers and streams. 

The building blocks of the Program are scientific investigations in 59 hydrologic basins 

(“study units”). Collectively, these study units cover one-half of the land area of the 

United States, encompass more than two-thirds of the water resources used in human 

activities, and include sources of drinking water used by 70 percent of the U.S. 

population served by public supplies.

The Program’s investigative methods balance the unique characteristics of 

individual watersheds with a nationally consistent emphasis on physical, chemical and 

biological evidence. Study-unit investigations proceed in 3 to 5 year rotations, with 

about one-third of the study units involved in intensive sampling at any given time. 

Each basin is revisited every 10 years to record trends.

The NAWQA Program

For more information, please contact:

850-942-9500

800-USA-MAPS

Copies of this report can be purchased 

from:
12

U.S. Geological Survey

Water-Resources Investigations Report 97-4152

1997

U.S. DEPARTMENT OF THE INTERIOR

BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY

Gordon P. Eaton, Director

Any use of trade, product, or firm names in this publication is for descriptive purposes only 

and does not imply endorsement by the U.S. Geological Survey