U.S. Department of the Interior

U.S. Geological Survey

SCALE 1:4,000

Lambert Conformal Conic projection

North American Datum of 1983 Approximate mean

declination, 2011

Magnetic

North

True North

141/2°

1,150

1,250

1,250

1,200

1,200

1,200

1,130

1,200

1,250

1,200

1,200

1,250

TABLE ROCK DAM

Boat dock

0 0.05 0.1 0.2 0.3 0.4 0.5 MILE

0 0.05 0.1 0.2 0.3 0.4 0.5 KILOMETER

82°41'

82°41'30"

82°42'

82°42'

82°40'30"

35°4'

35°4'

35°3'45"

35°3'45"

35°3'30"

82°40'30"

82°41'

82°41'30"

35°3'30"

EXPLANATION

Depth, in feet

0

150

1,200 Bathymetric contour–Line of equal lake-bottom elevation,

 in feet above National Geodetic Vertical Datum of 1929.

 Intervals are 10 feet

Bathymetric Maps and Water-Quality Profiles of Table Rock and North Saluda Reservoirs, Greenville County, South Carolina

By

Jimmy M. Clark, Celeste A. Journey, Douglas D. Nagle, and Timothy H. Lanier

2014

Scientific Investigations Map 3289

Plate 1 of 2

Figure 2. Bathymetric map of Table Rock Reservoir, Greenville County, South Carolina, May 2013.

Prepared in cooperation with Greenville Water

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

If printed, dimensional calibration may vary between electronic plotters and between X and Y directions on the same plotter, and paper may change size due to atmospheric 

conditions; therefore, scale and proportions may not be true on plots of this map.

Suggested citation:

Clark, J.M., Journey, C.A., Nagle, D.D., and Lanier, T.H., 2014, Bathymetric maps and water-quality profiles of Table Rock and North Saluda Reservoirs, Greenville County, 

South Carolina: U.S. Geological Survey Scientific Investigations Map 3289, 2 plates, http://dx.doi.org/10.3133/sim3289.

ISSN 2329-132X (online)

For additional information, please contact the Director, South Carolina Water Science Center, email: dc_sc@usgs.gov, or

visit http://sc.water.usgs.gov/.

Prepared by the Science Publishing Network, Raleigh Publishing Service Center

Abstract

Lakes and reservoirs are the water-supply source for many communities. As such, water-resource managers that oversee these water supplies 

require monitoring of the quantity and quality of the resource. Monitoring information can be used to assess the basic conditions within the 

reservoir and to establish a reliable estimate of storage capacity. In May 2013, a global navigation satellite system receiver and fathometer were 

used to collect bathymetric data, and an autonomous underwater vehicle was used to collect water-quality and bathymetric data at Table Rock 

Reservoir in Greenville County, South Carolina. These bathymetric data were used to create a bathymetric contour map and stage-area and stagevolume relation tables for the reservoir. Additionally, statistical summaries of the water-quality data were used to provide a general description of 

water-quality conditions in the reservoir.

Introduction

Greenville Water provides drinking water to more than 450,000 residents in the upstate region of South Carolina (Greenville Water, 

2011). The water authority obtains its drinking water from three surface-water sources: Table Rock Reservoir, North Saluda (also known as 

Poinsett) Reservoir, and Lake Keowee (fig. 1). Accurate storage capacity and water-quality data are vital for management and planning of the 

drinking-water supply. Therefore, detailed surveys of bathymetry and water quality for the Table Rock Reservoir were conducted to determine 

the stage (water-level)-volume relations and water-quality condition of the reservoir. The U.S. Geological Survey (USGS), in cooperation with 

Greenville Water, conducted bathymetric, water-quality, and imaging surveys of Table Rock Reservoir. The resulting datasets were used to 

produce a digital bathymetric map of the reservoir and to describe the basic water-quality conditions within the reservoir at the time of data 

collection.

Description of the Study Area

The Table Rock Reservoir is located in the foothills of the Blue Ridge Mountains in Greenville County, South Carolina (fig. 1) and was 

created in 1930 by the impoundment of the South Saluda River. Both the reservoir and the surrounding watershed are owned by Greenville Water, 

making it a well-protected source of drinking water. The watershed area, measured using a 10-meter (m) digital elevation model (DEM) (Gesch 

and others, 2002; Gesch, 2007) with a geographic information system (GIS), is 9,737 acres (15.2 square miles (mi2)). Table Rock Reservoir 

reaches full pool at an elevation of 1,250 feet (ft) relative to the National Geodetic Vertical Datum of 1929 (NGVD 29) (K.C. Price, Greenville 

Water, written commun., 2013). The surface area of the reservoir at full pool is 476 acres and includes 8.6 miles of shoreline.

Methods 

The YSI EcomapperTM autonomous underwater vehicle (AUV) was used, where possible, to collect bathymetric and water-quality data 

in the reservoir. The AUV can cost-effectively collect dense data by surveying large areas with minimal time compared to traditional manned 

boat surveys. Using the AUV, spatially dense Doppler Velocity Log (DVL) data were collected in the open-water and unobstructed areas of the 

reservoir. On the basis of initial site reconnaissance and using the AUV’s VectorMap planning software, a data-collection plan was established 

using selectable settings such as depth, speed, location, and sonar resolution. Georeferenced aerial imagery of the water body was loaded into 

VectorMap as background data for programming the surveys and establishing numbered waypoints, which are points placed by the user to 

indicate the route for the AUV to travel. For optimal efficiency of data collection and accuracy of the datasets, a transect spacing of approximately 

100 ft or 1 percent of the longitudinal length of the lake was used (Wilson and Richards, 2006). The AUV uses a Wide Area Augmentation 

System (WAAS) capable global positioning system (GPS) to navigate on the water surface and a DVL instrument for underwater navigation, 

which includes vertical beams for altitude and depth measurement. As a failsafe, the AUV can use an internal compass in the event that a problem 

occurs with the DVL. Vertical accuracy of the DVL at depths of 0 to 200 ft is ±0.4 ft (YSI, Incorporated, 2011).

In shallow areas (generally less than 3 ft), areas containing debris, or any area otherwise difficult for the AUV to maneuver, the bathymetric 

data were collected with digital echo sounding equipment attached to a manned boat. The data were collected by interfacing a 220-channel global 

navigation satellite system (GNSS) receiver and data logger to a dual-frequency fathometer and used methods described in Nagle and others 

(2009). Horizontal accuracy of both GPS types is typically less than 3 ft. The echo sounding equipment also was used as a quality-control check 

on selected AUV transects. The time measurement accuracy of echo sounding equipment typically is rated by manufacturers at ±0.1 ft plus 0.1 to 

0.5 percent of the depth (U.S. Army Corps of Engineers, 2002). To assess potential outliers and erroneous depth data, all data were post-processed 

and imported into a three-dimensional program called ArcScene. Data that were determined to be erroneous were removed from further processing and analysis. Using a GIS, the data then were used to create a triangulated irregular network (TIN), which digitally represents a surface 

(Environmental Systems Research Institute, 2013). Using methods described by Johnson and others (2008), the TIN was used to produce contour 

maps at 10-ft intervals and stage-volume relations. All GIS processing was accomplished by using Environmental Systems Research Institute 

(Esri) GIS software, including ArcScene, ArcMap, and 3-D Analyst extension (Environmental Systems Research Institute, 2013).

Water-quality data were collected simultaneously with the bathymetric data by using a bulkhead-mounted multiparameter sonde that 

is part of the AUV. The water-quality data were used to assess the spatial variability of water temperature, pH, specific conductance, and 

dissolved-oxygen concentrations. During the period of study, water-quality conditions in the reservoir were relatively uniform with minimal 

variability; therefore, no maps of the water-quality conditions were produced. Statistical summaries of the water-quality data are provided for the 

reservoir. In addition, near-surface and near-bottom measurements of water-quality conditions were made periodically and assessed to determine 

if changes in water quality occurred vertically in the water column. These water-quality data were collected using a hand-held multiparameter 

sonde from a manned boat. All water-quality sensors were calibrated prior to and after the deployment according to procedures outlined by YSI 

and the USGS National Field Manual (YSI, Incorporated, 2011; Wilde, variously dated; respectively).

Bathymetry and Storage Volumes

The maximum depth recorded in Table Rock Reservoir was 123 ft (fig. 2). On the basis of side-scan sonar data, there are many areas in the 

reservoir in which the relic stream channel is clearly visible. Also, no obvious areas of sediment buildup were detected. The reservoir is considered to be at full pool when the surface elevation reaches 1,250 ft. Using the 3-D Analyst extension within ArcMap, the volume of the reservoir 

at full pool was determined to be 1,180 x 106 cubic feet (ft3) (table 1; fig. 3). During the data-collection period, the highest recorded surface 

elevation was 1,250.2 ft.

Water-Quality Conditions

Spatial variability of water-quality conditions were assessed in Table Rock Reservoir for May 14–15, 2013. Subsequent data were collected 

on June 12, 2013, in order to add more depth data in targeted areas of the reservoir. As mentioned previously, water-quality conditions were 

relatively uniform and demonstrated minimal spatial variability.

 During the 2-day, data-collection period in May, water-quality data were collected near the surface at depths of 2 to 6 ft. The water 

temperature ranged from 17.3 to 21.1 degrees Celsius (oC) (table 2), and pH ranged from 5.4 to 6.3. Specific conductance ranged from 13 to 

14 microsiemens per centimeter (μS/cm) at 25 degrees Celsius, and dissolved-oxygen concentrations ranged from 9.4 to 9.7 milligrams per liter 

(mg/L).

 In order to determine vertical changes in the water column, a hand-held multiparameter sonde was used periodically to collect 

near-surface and near-bottom water-quality data. In Table Rock Reservoir, near-surface and near-bottom measurements of water temperature 

(17.8 and 8.2 oC, respectively) demonstrated a temperature change with depth, indicating some degree of thermal stratification (table 3). A 

different pattern, however, was identified for pH, specific conductance, and dissolved-oxygen concentrations in the reservoir, which had fairly 

constant measurements at both near-surface and near-bottom depths (table 3).

Purpose and Scope

The purpose of this report is to provide bathymetric, stage-volume, and water-quality data that can be used by water-resource managers to effectively 

plan and manage the resources available from the reservoir. Bathymetric, side-scan sonar, and water-quality data were collected at Table Rock Reservoir 

from May 14 to June 12, 2013. The bathymetric data were used to determine stage-volume relations, which can be used to assist water authorities in 

water-use planning. These relations are especially important during periods of high water usage or drought. Side-scan sonar data of the lake bed also 

were collected and used to verify and aid in the development of the bathymetric map. In addition, water temperature, pH, specific conductance, and 

dissolved-oxygen concentrations data were collected to provide a synoptic description of water-quality conditions in the reservoir.

This investigation of bathymetry and water-quality conditions in drinking-water reservoirs in South Carolina supports two of the six USGS strategic 

science directions (U.S. Geological Survey, 2007). The first strategy, Understanding Ecosystems and Predicting Ecosystem Change, is designed to study 

and monitor ecosystem change as well as interpret the findings and predictions for policymakers (U.S. Geological Survey, 2007). The second strategy is the 

Water Census of the United States, which informs the public and decision makers with, among other things, the status and changes of water resources and 

forecasting possible outcomes for water availability, water quality, and ecosystems caused by changing environments (U.S. Geological Survey, 2007).

Table 3. Near-surface and near-bottom water-quality data collected at Table Rock Reservoir, Greenville County, 

South Carolina, May 14–15, 2013.

Water-quality 

constituent Unit Near-surface measurement

Near-bottom 

measurement

Table Rock Reservoir

Water temperature Degrees Celsius 17.8 8.2

pH Standard units 6.7 6.6

Specific conductance Microsiemens per centimeter at 25 degrees Celsius 14 15

Dissolved-oxygen concentration Milligrams per liter 9.5 9.4

1,232

1,234

1,236

1,238

1,240

1,242

1,244

1,246

1,248

1,250

1,252

Elevation, in feet (NGVD 29)

850 900 950 1,000 1,050 1,100 1,150 1,200

Volume, in million cubic feet

Figure 3. Stage-volume curve at Table Rock Reservoir, Greenville County, 

South Carolina, May 2013. Acknowledgments

The authors would like to recognize the contributions of Greenville Water for providing boats and staff to assist in data collection.

Selected References

Environmental Systems Research Institute, 2013, ArcGIS Help 10.1: Redlands, Calif., Environmental Systems Research Institute, accessed 

December 10, 2013, at http://resources.arcgis.com/en/help/main/10.1/index.html#//00qn0000001p000000.

Gesch, D.B., 2007, The national elevation dataset, in Maune, D., ed., Digital elevation model technologies and applications—The DEM users 

manual (2d ed.): Bethesda, Md., American Society for Photogrammetry and Remote Sensing, p. 99–118.

Gesch, Dean, Oimoen, Michael, Greenlee, Susan, Nelson, Charles, Steuck, Michael, and Tyler, Dean, 2002, The national elevation dataset: 

Photogrammetric Engineering and Remote Sensing, v. 68, no. 1, p. 5–11.

Greenville Water, 2011, 2011 Water quality report, 4 p., accessed December 10, 2013, at http://www.greenvillewater.com/wp-content/

uploads/2013/02/waterquality.pdf.

Johnson, M.R., Andersen, M.J., and Sebree, S.K., 2008, Hydrographic surveys for six water bodies in eastern Nebraska, 2005–07: 

U.S. Geological Survey Scientific Investigations Report 2008–5048, 5 p.

Nagle and others, 2009, Bathymetry of lake William C. Bowen and Municipal Reservoir #1, Spartanburg County, South Carolina, 2008: 

U.S. Geological Survey Scientific Investigations Map 2009–3076, 1 sheet.

U.S. Army Corps of Engineers, 2002, Engineering and design—Hydrographic surveying, Publication No. EM 1110-2-1003, chap. 9, 3 p., 

accessed December 10, 2013, at http://140.194.76.129/publications/eng-manuals/EM_1110-2-1003_pfl/toc.htm.

U.S. Geological Survey, 2007, Facing tomorrow’s challenges—U.S. Geological Survey science in the decade 2007–2017: 

U.S. Geological Survey Circular 1309, 70 p.

Wilde, F.D., ed., variously dated, Field measurements: U.S. Geological Survey Techniques of Water-Resources Investigations, book 9, chap. A6, 

with sec. 6.0–6.8, accessed December 10, 2013, at http://water.usgs.gov/owq/FieldManual/Chapter6/Ch6_contents.html.

Wilson, G.L., and Richards, J.M., 2006, Procedural documentation and accuracy assessment of bathymetric maps and area/capacity tables for 

small reservoirs: U.S. Geological Survey Scientific Investigations Report 2006–5208, 14 p.

YSI, Incorporated, 2011, 6-Series multiparameter water quality sondes user manual: YSI, Incorporated, accessed December 10, 2013, at 

http://www.ysi.com/media/pdfs/069300-YSI-6-Series-Manual-RevH.pdf.

Table 1. Stage-area and stage-volume relations for selected elevations at 

Table Rock Reservoir, Greenville County, South Carolina, May 2013.

[NGVD 29, National Geodetic Vertical Datum of 1929]

Elevation 

(feet, NGVD 29) Surface area (acres) Volume (cubic feet x 106)

1,250.2 478 1,184

a

1,250 476 1,180

1,248 468 1,138

1,246 460 1,098

1,244 451 1,058

1,242 443 1,019

1,240 432 981

1,238 423 944

1,236 415 907

1,234 407 872

a

Full-pool elevation.

ANDERSON

COUNTY

PICKENS

COUNTY

SPARTANBURG

COUNTY

GREENVILLE

COUNTY

Greenville

ESRI® Data & Maps, 2010

North American Datum of 1983

Universal Transverse Mercator projection, zone 17

SOUTH CAROLINA

NORTH CAROLINA

North Saluda

Reservoir

0 2 4 6 8 MILES

0 2 4 6 8 KILOMETERS

Blue Ridge

Piedmont

Area shown

Lake

Keowee

Table Rock

Reservoir South

Saluda

River

Saluda

River

North

Saluda

River

NORTH CAROLINA

SOUTH CAROLINA

GEORGIA

29

25

276

123

276

178

176

25

N

Figure 1. Location of Table Rock and North Saluda Reservoirs and Lake Keowee, Greenville County, South Carolina.

Table 2. Statistical summary of water-quality conditions at Table Rock Reservoir, Greenville County, South Carolina, May 14–15, 2013. 

[Water-quality data were collected at a depth of 2 to 6 feet]

Water-quality constituent Unit Minimum Maximum Mean Median

Table Rock Reservoir

Water temperature Degrees Celsius 17.3 21.1 18.1 18.0

pH Standard units 5.4 6.3 5.8 5.8

Specific conductance Microsiemens per centimeter at 25 degrees Celsius 13 14 14 14

Dissolved-oxygen concentration Milligrams per liter 9.4 9.7 9.5 9.5
Approximate mean

declination, 2011

Magnetic

North

True North

141/2°

1,150

1,150

1,200

0 0.125 0.25 0.50 MILE

0 0.125 0.25 0.50 KILOMETER

82°23'30"

82°22'30"

82°22'30"

82°23'30"

82°23'

82°23'

82°25'

82°24'30"

82°24'30"

82°24'

82°24'

35°9'30"

35°9'

35°9'

35°8'30" 35°8'30"

82°23'30"

82°24'

82°25'

82°24'30"

35°9'30"

1,200

1,200

1,200

1,150

1,150

1,200

1,100

1,150

1,100

1,200

1,150

EXPLANATION

Depth, in feet

0

150

1,200 Bathymetric contour–Line of equal lake-bottom

 elevation, in feet above National Geodetic

 Vertical Datum of 1929.

 Intervals are 10 feet

Boat dock

NORTH SALUDA DAM

SCALE 1:6,000

Lambert Conformal Conic projection

North American Datum of 1983

U.S. Department of the Interior

U.S. Geological Survey

Bathymetric Maps and Water-Quality Profiles of Table Rock and North Saluda Reservoirs, Greenville County, South Carolina

By

Jimmy M. Clark, Celeste A. Journey, Douglas D. Nagle, and Timothy H. Lanier

2014

Scientific Investigations Map 3289

Plate 2 of 2

Figure 2. Bathymetric map of North Saluda Reservoir, Greenville County, South Carolina, April 2013.

Prepared in cooperation with Greenville Water

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

If printed, dimensional calibration may vary between electronic plotters and between X and Y directions on the same plotter, and paper may change size due to atmospheric 

conditions; therefore, scale and proportions may not be true on plots of this map.

Suggested citation:

Clark, J.M., Journey, C.A., Nagle, D.D., and Lanier, T.H., 2014, Bathymetric maps and water-quality profiles of Table Rock and North Saluda Reservoirs, Greenville County, 

South Carolina: U.S. Geological Survey Scientific Investigations Map 3289, 2 plates, http://dx.doi.org/10.3133/sim3289.

ISSN 2329-132X (online)

For additional information, please contact the Director, South Carolina Water Science Center, email: dc_sc@usgs.gov, or

visit http://sc.water.usgs.gov/.

Prepared by the Science Publishing Network, Raleigh Publishing Service Center

Figure 3. Stage-volume curve at North Saluda Reservoir, Greenville County, 

South Carolina, April 2013.

ANDERSON

COUNTY

PICKENS

COUNTY

SPARTANBURG

COUNTY

GREENVILLE

COUNTY

Greenville

ESRI® Data & Maps, 2010

North American Datum of 1983

Universal Transverse Mercator projection, zone 17

SOUTH CAROLINA

NORTH CAROLINA

North Saluda

Reservoir

0 2 4 6 8 MILES

0 2 4 6 8 KILOMETERS

Blue Ridge

Piedmont

Area shown

Lake

Keowee

Table Rock

Reservoir South

Saluda

River

Saluda

River

North

Saluda

River

NORTH CAROLINA

SOUTH CAROLINA

GEORGIA

29

25

276

123

276

178

176

25

N

Figure 1. Location of Table Rock and North Saluda Reservoirs and Lake Keowee, Greenville County, South Carolina.

Purpose and Scope

The purpose of this report is to provide bathymetric, stage-volume, and water-quality data that can be used by water-resource managers 

to effectively plan and manage the resources available from the reservoir. Bathymetric, side-scan sonar, and water-quality data were collected 

at North Saluda Reservoir from April 15 to June 12, 2013. The bathymetric data were used to determine stage-volume relations, which can be 

used to assist water authorities in water-use planning. These relations are especially important during periods of high water usage or drought. 

Side-scan sonar data of the lake bed also were collected and used to verify and aid in the development of the bathymetric map. In addition, 

water temperature, pH, specific conductance, and dissolved-oxygen concentrations data were collected to provide a synoptic description of 

water-quality conditions in the reservoir. 

This investigation of bathymetry and water-quality conditions in drinking-water reservoirs in South Carolina supports two of the six USGS 

strategic science directions (U.S. Geological Survey, 2007). The first strategy, Understanding Ecosystems and Predicting Ecosystem Change, 

is designed to study and monitor ecosystem change as well as interpret the findings and predictions for policymakers (U.S. Geological Survey, 

2007). The second strategy is the Water Census of the United States, which informs the public and decision makers with, among other things, the 

status and changes of water resources and forecasting possible outcomes for water availability, water quality, and ecosystems caused by changing 

environments (U.S. Geological Survey, 2007).

Description of the Study Area

The North Saluda Reservoir, which also is known as the Poinsett Reservoir, is located in the foothills of the Blue Ridge Mountains in 

Greenville County, South Carolina (fig. 1). The reservoir was created by the impoundment of the North Saluda River and was put into operation 

in 1961. Both the reservoir and the surrounding watershed are owned by Greenville Water, making it a well-protected source of drinking water. 

The watershed area, measured using a 10-meter (m) digital elevation model (DEM) (Gresch and others, 2002; Gesch, 2007) with a geographic 

information system (GIS), is 16,122 acres (25.2 square miles (mi2)). North Saluda Reservoir reaches full pool at an elevation of 1,230 feet (ft) 

relative to the National Geodetic Vertical Datum of 1929 (NGVD 29) (K.C. Price, Greenville Water, written commun., 2013). The surface area of 

the reservoir at full pool is 1,049 acres and includes 17.9 miles of shoreline.

Methods 

The YSI EcomapperTM autonomous underwater vehicle (AUV) was used, where possible, to collect bathymetric and water-quality data 

in the reservoir. The AUV can cost-effectively collect dense data by surveying large areas with minimal time compared to traditional manned 

boat surveys. Using the AUV, spatially dense Doppler Velocity Log (DVL) data were collected in the open-water and unobstructed areas of the 

reservoir. On the basis of initial site reconnaissance and using the AUV’s VectorMap planning software, a data-collection plan was established 

using selectable settings such as depth, speed, location, and sonar resolution. Georeferenced aerial imagery of the water body was loaded into 

VectorMap as background data for programming the surveys and establishing numbered waypoints, which are points placed by the user to 

indicate the route for the AUV to travel. For optimal efficiency of data collection and accuracy of the datasets, a transect spacing of approximately 

100 ft or 1 percent of the longitudinal length of the lake was used (Wilson and Richards, 2006). The AUV uses a Wide Area Augmentation 

System (WAAS) capable global positioning system (GPS) to navigate on the water surface and a DVL instrument for underwater navigation, 

which includes vertical beams for altitude and depth measurement. As a failsafe, the AUV can use an internal compass in the event that a problem 

occurs with the DVL. Vertical accuracy of the DVL at depths of 0 to 200 ft is ±0.4 ft (YSI, Incorporated, 2011).

In shallow areas (generally less than 3 ft), areas containing debris, or any area otherwise difficult for the AUV to maneuver, the bathymetric 

data were collected with digital echo sounding equipment attached to a manned boat. The data were collected by interfacing a 220-channel 

global navigation satellite system (GNSS) receiver and data logger to a dual-frequency fathometer and used methods described in Nagle and 

others (2009). Horizontal accuracy of both GPS types is typically less than 3 ft. The echo sounding equipment also was used as a quality-control 

check on selected AUV transects. The time measurement accuracy of echo sounding equipment typically is rated by manufacturers at ±0.1 ft 

plus 0.1 to 0.5 percent of the depth (U.S. Army Corps of Engineers, 2002). To assess potential outliers and erroneous depth data, all data were 

post-processed and imported into a three-dimensional program called ArcScene. Data that were determined to be erroneous were removed from 

further processing and analysis. Using a GIS, the data then were used to create a triangulated irregular network (TIN), which digitally represents a 

surface (Environmental Systems Research Institute, 2013). Using methods described by Johnson and others (2008), the TIN was used to produce 

contour maps at 10-ft intervals and stage-volume relations. All GIS processing was accomplished by using Environmental Systems Research 

Institute (Esri) GIS software, including ArcScene, ArcMap, and 3-D Analyst extension (Environmental Systems Research Institute, 2013).

Water-quality data were collected simultaneously with the bathymetric data by using a bulkhead-mounted multiparameter sonde that 

is part of the AUV. The water-quality data were used to assess the spatial variability of water temperature, pH, specific conductance, and 

dissolved-oxygen concentrations. During the period of study, water-quality conditions in the reservoir were relatively uniform with minimal 

variability; therefore, no maps of the water-quality conditions were produced. Statistical summaries of the water-quality data are provided for the 

reservoir. In addition, near-surface and near-bottom measurements of water-quality conditions were made periodically and assessed to determine 

if changes in water quality occurred vertically in the water column. These water-quality data were collected using a hand-held multiparameter 

sonde from a manned boat. All water-quality sensors were calibrated prior to and after the deployment according to procedures outlined by YSI 

and the USGS National Field Manual (YSI, Incorporated, 2011; Wilde, variously dated; respectively).

Bathymetry and Storage Volumes

The maximum depth recorded in North Saluda Reservoir was 149.5 ft (fig. 2). Side-scan sonar did not indicate any obvious sediment 

buildup and, similar to Table Rock Reservoir, the relic stream channel was distinct throughout the reservoir. North Saluda Reservoir is considered 

to be at full pool when the surface elevation reaches 1,230 ft. Reservoir volume at this level was determined to be 3,181 x 106 cubic feet (ft3) 

(table 1; fig. 3). During the data-collection period, the highest recorded surface elevation was 1,230.3 ft.

Abstract

Lakes and reservoirs are the water-supply source for many communities. As such, water-resource managers that oversee these water 

supplies require monitoring of the quantity and quality of the resource. Monitoring information can be used to assess the basic conditions within 

the reservoir and to establish a reliable estimate of storage capacity. In April and May 2013, a global navigation satellite system receiver and 

fathometer were used to collect bathymetric data, and an autonomous underwater vehicle was used to collect water-quality and bathymetric data 

at North Saluda Reservoir in Greenville County, South Carolina. These bathymetric data were used to create a bathymetric contour map and 

stage-area and stage-volume relation tables for the reservoir. Additionally, statistical summaries of the water-quality data were used to provide a 

general description of water-quality conditions in the reservoir.

Introduction

Greenville Water provides drinking water to more than 450,000 residents in the upstate region of South Carolina (Greenville Water, 

2011). The water authority obtains its drinking water from three surface-water sources: Table Rock Reservoir, North Saluda (also known as 

Poinsett) Reservoir, and Lake Keowee (fig. 1). Accurate storage capacity and water-quality data are vital for management and planning of the 

drinking-water supply. Therefore, detailed surveys of bathymetry and water-quality for the North Saluda Reservoir were conducted to determine 

the stage (water-level)-volume relations and water-quality condition of the reservoir. The U.S. Geological Survey (USGS), in cooperation with 

Greenville Water, conducted bathymetric, water-quality, and imaging surveys of North Saluda Reservoir. The resulting datasets were used to 

produce a digital bathymetric map of the reservoir and to describe the basic water-quality conditions within the reservoir at the time of data 

collection.

Water-Quality Conditions

Spatial variability of water-quality conditions were assessed in North Saluda Reservoir for April 15–18, 2013. Subsequent data were 

collected on June 12, 2013, in order to add more depth data in targeted areas of the reservoir. Data collection targeted a depth of 2 to 6 ft except 

in areas where depth exceeded the sensor range. The only instance where depth exceeded the sensor range occurred in the area near the dam out 

to approximately 2,000 ft upstream from the dam where depths reached nearly 150 ft. In order to collect these data, the AUV was programmed 

to operate in this target area at a depth of 35 ft. As mentioned previously, water-quality conditions were relatively uniform and demonstrated 

minimal spatial variability.

 In North Saluda Reservoir, during the 4-day, data-collection period in April, water-quality data were collected near the surface at depths of 

2 to 6 ft. The water temperature ranged from 14.2 to 18.1 oC (table 2), and pH ranged from 5.6 to 6.8. Specific conductance was higher in North 

Saluda Reservoir when compared to Table Rock Reservoir, ranging from 23 to 24 microsiemens per centimeter (μS/cm), and dissolved oxygen 

ranged from 10.2 to 10.7 milligrams per liter (mg/L).

In order to determine vertical changes in the water column, a hand-held multiparameter sonde was used periodically to collect near-surface 

and near-bottom water-quality data. In North Saluda Reservoir, near-surface and near-bottom measurements of water temperature (16.6 and 

8.3 oC, respectively) demonstrated a temperature change with depth (table 3). As was observed in Table Rock Reservoir (plate 1), pH, specific 

conductance, and dissolved-oxygen concentrations in this reservoir were unaffected by the thermal stratification and had fairly constant 

measurements at both near-surface and near-bottom depths (table 3).

Table 1. Stage-area and stage-volume relations for selected elevations at 

North Saluda Reservoir, Greenville County, South Carolina, April 2013.

[NGVD 29, National Geodetic Vertical Datum of 1929]

Elevation 

(feet, NGVD 29) Surface area (acres) Volume (cubic feet x 106)

1,230.3 1,052 3,195

a

1,230 1,049 3,181

1,228 1,033 3,091

1,226 1,018 3,001

1,224 1,003 2,913

1,222 988 2,826

1,220 970 2,741

1,218 949 2,657

1,216 931 2,575

1,214 913 2,495

a

Full-pool elevation.

1,212

1,214

1,216

1,218

1,220

1,222

1,224

1,226

1,228

1,230

1,232

2,400 2,600 2,800 3,000 3,200 3,400

Elevation, in feet (NGVD 29)

Volume, in million cubic feet

Selected References

Environmental Systems Research Institute, 2013, ArcGIS Help 10.1: Redlands, Calif., Environmental Systems Research Institute, accessed 

December 10, 2013, at http://resources.arcgis.com/en/help/main/10.1/index.html#//00qn0000001p000000.

Gesch, D.B., 2007, The national elevation dataset, in Maune, D., ed., Digital elevation model technologies and applications—The DEM users 

manual (2d ed.): Bethesda, Md., American Society for Photogrammetry and Remote Sensing, p. 99–118.

Gesch, Dean, Oimoen, Michael, Greenlee, Susan, Nelson, Charles, Steuck, Michael, and Tyler, Dean, 2002, The national elevation dataset: 

Photogrammetric Engineering and Remote Sensing, v. 68, no. 1, p. 5–11.

Greenville Water, 2011, 2011 Water quality report, 4 p., accessed December 10, 2013, at http://www.greenvillewater.com/wp-content/

uploads/2013/02/waterquality.pdf.

Johnson, M.R., Andersen, M.J., and Sebree, S.K., 2008, Hydrographic surveys for six water bodies in eastern Nebraska, 2005–07: 

U.S. Geological Survey Scientific Investigations Report 2008–5048, 5 p.

Nagle and others, 2009, Bathymetry of lake William C. Bowen and Municipal Reservoir #1, Spartanburg County, South Carolina, 2008: 

U.S. Geological Survey Scientific Investigations Map 2009–3076, 1 sheet.

U.S. Army Corps of Engineers, 2002, Engineering and design—Hydrographic surveying, Publication No. EM 1110-2-1003, chap. 9, 3 p., 

accessed December 10, 2013, at http://140.194.76.129/publications/eng-manuals/EM_1110-2-1003_pfl/toc.htm.

U.S. Geological Survey, 2007, Facing tomorrow’s challenges—U.S. Geological Survey science in the decade 2007–2017: 

U.S. Geological Survey Circular 1309, 70 p.

Wilde, F.D., ed., variously dated, Field measurements: U.S. Geological Survey Techniques of Water-Resources Investigations, book 9, chap. A6, 

with sec. 6.0–6.8, accessed December 10, 2013, at http://water.usgs.gov/owq/FieldManual/Chapter6/Ch6_contents.html.

Wilson, G.L., and Richards, J.M., 2006, Procedural documentation and accuracy assessment of bathymetric maps and area/capacity tables for 

small reservoirs: U.S. Geological Survey Scientific Investigations Report 2006–5208, 14 p.

YSI, Incorporated, 2011, 6-Series multiparameter water quality sondes user manual: YSI, Incorporated, accessed December 10, 2013, at 

http://www.ysi.com/media/pdfs/069300-YSI-6-Series-Manual-RevH.pdf.

Table 2. Statistical summary of water-quality conditions at North Saluda Reservoir, Greenville County, South Carolina, 

April 15–18, 2013.

[Water-quality data were collected at a depth of 2 to 6 feet]

Water-quality 

constituent Unit Minimum Maximum Mean Median

North Saluda Reservoir

Water temperature Degrees Celsius 14.2 18.1 15.0 14.9

pH Standard units 5.6 6.8 6.3 6.3

Specific conductance Microsiemens per centimeter at 25 degrees Celsius 23 24 23.8 24

Dissolved-oxygen concentration Milligrams per liter 10.2 10.7 10.4 10.4

Table 3. Near-surface and near-bottom water-quality data collected at North Saluda Reservoir, Greenville County, 

South Carolina, April 15–18, 2013.

Water-quality 

constituent Unit Near-surface measurement

Near-bottom 

measurement

North Saluda Reservoir

Water temperature Degrees Celsius 16.6 8.3

pH Standard units 6.9 6.8

Specific conductance Microsiemens per centimeter at 25 degrees Celsius 23 24

Dissolved-oxygen concentration Milligrams per liter 9.8 9.7

Acknowledgments

The authors would like to recognize the contributions of Greenville Water for providing boats and staff to assist in data collection.