Introduction

On December 14, 2005, the embankment of the upper reservoir at the Taum Sauk pump storage facility, 

Reynolds County, Missouri, catastrophically failed and flooded the East Fork Black River, depositing debris 

and sediment in Johnson’s Shut-Ins State Park, the lower Taum Sauk Reservoir, and downstream in the Black 

River (location map). A bathymetric survey conducted December 20–22, 2005, documented the bathymetry of 

the lower Taum Sauk Reservoir after the upper reservoir failure (Rydlund, 2006). After subsequent excavation 

of sediment and debris from the lower reservoir by Ameren Union Electric (UE), the U.S. Geological Survey 

(USGS), in collaboration with Roux Associates Inc., conducted a bathymetric survey of the lower Taum Sauk 

Reservoir on June 16–19, 2008, to prepare a current (2008) bathymetric map (fig. 1) for the lower reservoir, 

establish a current (2008) elevation-area and capacity table, and determine reservoir area and capacity differences between the 2005 and 2008 bathymetric surveys. 

Acknowledgments

The USGS thanks Ameren UE for granting access to their property for the survey. 

Methods

Bathymetric data (water depths and positions) were collected on June 16–19, 2008 (fig. 2). Position data 

were collected using a boat-mounted differentially corrected global positioning system (DGPS). Water depths 

were collected using a survey-grade 200-kilohertz echo sounder emitting sound pulses that are reflected off 

the reservoir bottom and received by a transducer. In some areas of the reservoir, water depths were measured 

manually (target data-collection points) using a steel rod graduated in tenths, because the water depth was 

below the minimum operating depth [approximately 2.5 feet (ft)] of the echo-sounding equipment. Water-surface edge points were collected using only the DGPS coordinate data with no depth. Approximately 350,000 

data points were collected in the 2008 survey. Bathymetric data were collected with the echo sounder along 

transect lines spaced approximately 50 ft apart, which is approximately 0.5 percent of the longitudinal length 

of the reservoir. Individual data-collection points along a transect line were approximately 0.7 to 1.6 ft apart. 

Water-depth data were converted to reservoir-bottom elevation by subtracting the depths at each location from 

the reference water-surface elevation of the reservoir. The reference water-surface elevation was determined 

by measuring from surveyed reference marks of known elevation (figs. 1 and 3). Elevations of these reference 

marks were obtained from the Missouri Department of Natural Resources (O. Lashley, Missouri Department 

of Natural Resources Division of Geology and Land Survey, oral commun., 2006). The reference marks were 

not used to establish or verify horizontal datum. The position data were used as collected from the DGPS with 

a stated positional accuracy of less than 3.28 ft (Trimble Navigation Limited, 1999). The vertical datum is 

North American Vertical Datum 1988 (NAVD 88) and the horizontal datum is North American Datum 1983 

(NAD 83). 

Geographic information system (GIS) software was used to produce a three-dimensional surface of the 

reservoir-bottom elevations from the bathymetric data. The boundary of the reservoir at full pool elevation 

was determined from laser intensity detection and ranging (LIDAR) data collected in December 2005 (Sanborn, Inc., written commun., 2005). The 2008 boundary was altered where changes were seen from collected 

edge points and 2008 imagery. The surface between the 2008 and 2005 surveyed data and the full pool boundary was created using established interpolation techniques (Wilson and Richards, 2006). An area and capacity 

table was produced from the three-dimensional surface (table 1) showing surface area and water volumes at 

specified elevations. The surface was contoured using GIS software and the contours were cartographically 

edited to create a bathymetric map (fig. 1). 

A bathymetric map (fig. 3) of the lower Taum Sauk Reservoir was created and an elevation-area and 

capacity table (table 2) was computed from the survey data collected by the USGS in December 2005. After 

the failure of the upper reservoir (Rydlund, 2006), a bathymetric survey was conducted by the USGS in 

December 2005. Both the 2008 and the 2005 surveys collected data along similar transect lines (figs. 2 and 4) 

and both bathymetric maps (figs. 1 and 3) were created using methods documented in Wilson and Richards 

(2006). Approximately 311,000 data points were collected in the 2005 survey. Additional data points were collected for the 2008 survey because the reservoir water-level was higher in 2008, and debris deposited during 

the 2005 flood had been removed allowing access to more reservoir area (figs. 2 and 4). 

The area and capacity tables from the two surveys were compared by calculating the difference between 

the two tables for each elevation (table 3). To produce the bathymetric surface difference map (fig. 5), the 

2008 and 2005 bathymetric surfaces were first converted into an evenly spaced elevation grid of 3.28-ft cell 

size, then the difference was computed by subtracting the 2005-surface grid from the 2008-surface grid.

Quality Assurance

Accuracy of the bathymetric surface and contours is a function of the survey data accuracy, density of the 

survey data (transect interval and data-collection frequency), and the processing steps that occur during their 

creation. Onsite, a bar check consisting of measurements of depth to a suspended steel plate was performed at 

the beginning of each day of data collection following established protocols (U.S. Army Corps of Engineers, 

2002; Wilson and Richards, 2006) to ensure that the echo sounder was calibrated correctly. The water-surface 

elevation was determined at the beginning and end of each day of data collection using established reference 

markers as vertical controls (figs. 1 and 3) to ensure an accurate computation of reservoir-bottom elevation. 

Survey echo sounder data accuracy also is dependent on factors such as vessel draft/index errors, platform 

stability, vessel velocity, and subsurface material density (Wilson and Richards, 2006). Though similar, these 

factors were not exactly the same for the 2008 and 2005 surveys because of weather conditions, instantaneous boat speeds, and consolidation/compaction of bottom sediments. 

To assess the quality of the 2008 bathymetric surface and contours, quality-assurance data were collected using similar transect lines that were used to assess quality assurance of the 2005 bathymetric surface. 

The quality assurance-transects were spaced approximately 250 ft apart (figs. 2 and 4) and were oriented at 

an oblique angle (about 40 degrees) to the survey transects. Data from the quality-assurance transects were 

used as an independent data set allowing for computation of accuracy of the bathymetric surface and bathymetric-contour map (Wilson and Richards, 2006). Approximately 54,400 quality-assurance data points were 

collected for the 2008 survey (fig. 2) and approximately 31,700 quality-assurance data points were collected 

for the 2005 survey (fig. 4). More quality-assurance data points were collected for the 2008 survey because 

more reservoir area was open for surveying in 2008. The vertical accuracies of the 2008 and 2005 bathymetric surfaces, from which the elevation-area and capacity tables were derived, were computed to be 0.77 and 

1.45 ft at the 95 percent confidence level. The vertical accuracies of the 2008 and 2005 bathymetric contour 

maps were computed to be 2.72 and 3.38 ft at the 95 percent confidence level. Bathymetric contours are less 

accurate than the bathymetric surface because of cartographic interpretation of the contours for map display.

Differences in Reservoir Bathymetry, Area, and Capacity 

The water-surface elevation of the reservoir was approximately 750.3 ft during the 2008 survey, which 

is equal to the spillway elevation. For the 2005 survey, the water-surface elevation of the reservoir was 3.0 ft 

lower at 747.3 ft. Excavation of sediment and debris occurred between the two surveys. Using the area and 

capacity table for each survey, the difference in the reservoir surface area and capacity (volume) between the 

2008 and 2005 surveys was computed at each elevation. At the elevation of 750 ft, the 2008 reservoir surface 

was 3 acres greater than the 2005 surface and the 2008 capacity was 620 acre-feet (acre-ft)greater than the 

2005 capacity (table 3). The small differences in area and capacity between the 2008 reservoir surface and 

the 2005 reservoir surface at elevations below 714 ft are confined to the tailrace immediately downstream 

from the power generation turbines at the north end of the reservoir, where the 2005 data coverage is less 

dense than the coverage in 2008.

The elevation difference map (fig. 5) shows areas of change between the two bathymetric surfaces of 

the reservoir bottom. Generally, the 2008 reservoir bottom surface is lower than the 2005 surface in the East 

Fork Black River arm, the Walker Branch cove, the area upstream from the dam, the northeast part of the 

Taum Sauk Creek arm, and areas identified as sedimentation basins (MACTEC Engineering and Consulting, Inc., oral commun., 2008) on the north side of the Taum Sauk Creek arm of the reservoir. Areas that 

show the 2008 surface higher than the 2005 surface are areas identified as haul roads (MACTEC Engineering and Consulting, Inc., oral commun., 2008) in the Taum Sauk Creek arm and East Fork Black River arm, 

the upper end of the Taum Sauk Creek arm, and the reach downstream from the sedimentation dam. Some 

larger elevation differences near the reservoir shore and at the upper end of some coves are the result of no 

coincident survey data in these areas for the 2008 and 2005 surveys. Because the water-surface elevation for 

the 2005 survey was lower and debris made some areas inaccessible, survey data in 2005 could not be collected in areas such as the Walker Branch cove, the upper end of the Taum Sauk Creek arm, upstream from 

the sedimentation dam, and between elevations 747.3 and 750 ft (figs. 2 and 4), and data interpolation was 

used to extend the bathymetric surface in these areas. As a result, elevation differences in these areas are less 

accurate than where the 2008 and 2005 survey data are coincident. 

References Cited

Rydlund, P.H., Jr., 2006, Peak discharge, flood profile, flood inundation, and debris movement accompanying 

the failure of the upper reservoir at the Taum Sauk pump storage facility near Lesterville, Missouri: U.S. 

Geological Survey Scientific Investigations Report 2006–5284, 45 p.

Trimble Navigation Limited, 1999, AgGPS 124/132 operation manual, revision B: Trimble Precision Agricultural Systems, 218 p.

U.S. Army Corps of Engineers, 2002, Engineering and design-hydrographic surveying manual No. 

1110–2–1003: Washington, D.C., 510 p.

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, 24 p.

l

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Turbines

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90°49'

90°49'

90°49'30"

90°49'30"

90°50'

90°50'

90°50'30"

90°50'30"

37°31' 37°31'

37°30'30" 37°30'30"

37°30'

37°30'

0 1,000 2,000 FEET

0 300 600 METERS

Universal Transverse Mercator projection, Zone 15

Horizontal coordinate information referenced to the

North American Datum 1983 (NAD 83)

EXPLANATION

750

740

RM2

RM1

RM3

RM1

Bathymetric contour—Shows elevation of the reservoir bottom. 

Contour interval 2 feet. Elevations referenced to North American 

Datum 1988 (NAVD 88). Contours tested 2.72 feet vertical 

accuracy at 95 percent confidence level. Hachures indicate closed 

low

Water surface—Shows approximate elevation of water surface, 

June 16−19, 2008

U.S. Geological Survey reference marker and identifier— 

RM1-chiseled arrow on northeast corner of concrete outlet structure 

at dam. Elevation 750.26 feet. RM2-chiseled arrow on down 

stream curb at boat ramp. Elevation 747.47 feet. RM3-chiseled 

arrow on downstream corner of left abutment of sediment dam. 

Elevation 760.27 feet

East Fork Black River arm

Taum Sauk Creek arm

Walker Branch cove

Lower Taum

Sauk Reservoir

90°49'

90°49'

90°49'30"

90°49'30"

90°50'

90°50'

90°50'30"

90°50'30"

37°31' 37°31'

37°30'30" 37°30'30"

37°30' 37°30'

0 1,000 2,000 FEET

0 300 600 METERS

Universal Transverse Mercator projection, Zone 15

Horizontal coordinate information referenced to the

North American Datum 1983 (NAD 83)

EXPLANATION

Data-collection points on transect lines

Quality assurance data-collection points 

 on transect lines

Individual target data-collection point

750

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90°49'

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90°50'30"

37°31' 37°31'

37°30'30" 37°30'30"

37°30'

37°30'

0 1,000 2,000 FEET

0 300 600 METERS

Universal Transverse Mercator projection, Zone 15

Horizontal coordinate information referenced to the

North American Datum 1983 (NAD 83)

EXPLANATION

747.3

750

RM2

RM1

RM3

RM1

Bathymetric contour—Shows elevation of the reservoir bottom. Contour 

interval 2 feet. Elevations referenced to North American Datum 1988 

(NAVD 88). Contours tested 3.38 feet vertical accuracy at 95 percent 

confidence level. Hachures indicate closed low

Water surface—Shows approximate elevation of water surface, 

December 20–22, 2005 

U.S. Geological Survey reference marker and identifier— RM1- 

chiseled arrow on northeast corner of concrete outlet structure at dam. 

Elevation 750.26 feet. RM2-chiseled arrow on downstream curb at 

boat ramp. Elevation 747.47 feet. RM3-chiseled arrow on downstream 

corner of left abutment of sediment dam. Elevation 760.27 feet

East Fork Black River arm

Taum Sauk Creek arm

Walker Branch cove

Lower Taum

Sauk Reservoir

90°49'

90°49'

90°49'30"

90°49'30"

90°50'

90°50'

90°50'30"

90°50'30"

37°31' 37°31'

37°30'30" 37°30'30"

37°30' 37°30'

0 1,000 2,000 FEET

0 300 600 METERS

Universal Transverse Mercator projection, Zone 15

Horizontal coordinate information referenced to the

North American Datum 1983 (NAD 83)

EXPLANATION

Data-collection points on transect lines

Quality assurance data-collection points 

 on transect lines

Individual target data-collection point

90°49'

90°49'

90°49'30"

90°49'30"

90°50'00"

90°50'

90°50'30"

90°50'30"

37°31' 37°31'

37°30'30" 37°30'30"

37°30'

Sedimentation

basins

Haul road

Haul road

Haul road

37°30'

0 1,000 2,000 FEET

0 300 600 METERS

Universal Transverse Mercator projection, Zone 15

Horizontal coordinate information referenced to the

North American Datum 1983 (NAD 83)

EXPLANATION

Bathymetric surface difference—Change between the bathymetric 

survey of December 20–22, 2005, and June 16–19, 2008

East Fork Black River arm

Taum Sauk Creek arm

Walker Branch cove

Lower Taum

Sauk Reservoir

Increase, in feet Decrease, in feet

Greater than 8

7 to 8

6 to 7

5 to 6

4 to 5

3 to 4

2 to 3

1 to 2

0 to 1

Greater than 8

7 to 8

6 to 7

5 to 6

4 to 5

3 to 4

2 to 3

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0 to 1

Approximate boundary of reservoir at full pool elevation

Dam

Sedimentation 

dam

Turbines

Johnson’s

Shut-Ins

State Park

Lesterville Centerville

Ellington

21

21

49

Fork Black River

River

Creek

Lower Taum

Sauk Reservoir

Upper Taum East Fork

Black River

Sauk Reservoir

Clearwater

Lake

Black River

Logan

Taum

Sauk

Sinking

Creek

Black

Middle

West Fork

Creek

Reynolds

County

Location map

Missouri

Differences in Reservoir Bathymetry, Area, and Capacity Between December 20–22, 2005, and June 16–19, 2008, for 

Lower Taum Sauk Reservoir, Reynolds County, Missouri

By

Gary L. Wilson and Joseph M. Richards

2008

SCIENTIFIC INVESTIGATIONS MAP 3061

Bathymetry, Area, and Capacity Differences for Lower 

Taum Sauk Reservoir

Wilson, G.L., and Richards, J.M., 2008, Differences in Reservoir Bathymetry, Area, and Capacity Between 

December 20–22, 2005, and June 16–19, 2008, for Lower Taum Sauk Reservoir, Reynolds County, Missouri

Prepared in collaboration with 

ROUX ASSOCIATES INC.

Publishing support provided by: 

Rolla Publishing Service Center

For additional information concerning this publication, contact:

Director, USGS Missouri Water Science Center 

1400 Independence Road, MS 100

Rolla, MO 65401

(573) 308–3667

Or visit the Missouri Water Science Center Web Site at:

http://mo.water.usgs.gov

Suggested citation:

Wilson, G.L., and Richards, J.M., 2008, Differences in reservoir bathymetry, 

area, and capacity between December 20–22, 2005, and June 16–19, 2008, 

for lower Taum Sauk Reservoir, Reynolds County, Missouri: U.S. Geological 

Survey Scientific Investigations Map 3061, 1 sheet.

For more information about USGS and its products:

Telephone: 1-888-ASK-USGS

World Wide Web: http://www.usgs.gov

U.S. DEPARTMENT OF THE INTERIOR

U.S. GEOLOGICAL SURVEY

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

U.S. Government.

Table 1. Reservoir area and water capacity 

(volume) at specified elevations for lower Taum 

Sauk Reservoir, June 16–19, 2008.

[Reservoir spillway elevation is 750.3 feet; elevation 747.3 

feet is water-surface elevation during 2005 survey; elevations 

referenced to North American Vertical Datum 1988 (NAVD 

88); volumes calculated from surface testing 0.77-foot vertical 

accuracy at 95 percent confidence level]

Elevation, 

in feet

Area, 

in acres

Capacity, 

in acre-feet

692 0 0

694 0 0

696 .02 .02

698 .06 .10

700 .10 .16

702 .13 .48

704 .17 .78

706 .21 1.16

708 .25 1.62

710 .30 2.16

712 .34 2.80

714 .95 3.81

716 4.44 7.92

718 14.9 26.8

720 28.7 69.5

722 47.7 144

724 68.3 261

726 88.2 417

728 111 615

730 133 859

732 152 1,140 

734 174 1,470 

736 211 1,850 

738 238 2,300 

740 258 2,800 

742 274 3,330 

744 292 3,900 

745 301 4,190 

746 309 4,500 

747.3 322 4,910 

748 330 5,130 

750 358 5,810 

Table 2. Reservoir area and water capacity 

(volume) at specified elevations for lower Taum 

Sauk Reservoir, December 20–22, 2005. 

[Reservoir spillway elevation is 750.3 feet; elevation 747.3 feet is 

water-surface elevation; elevations referenced to North American 

Vertical Datum 1988 (NAVD 88); volumes calculated from surface 

testing 1.45-feet vertical accuracy at 95 percent confidence level]

Elevation, 

in feet

Area, 

in acres

Capacity, 

in acre-feet

692 0.13 0.03

694 .14 .30

696 .15 .59

698 .16 .91

700 .17 1.2

702 .19 1.6

704 .20 2.0

706 .21 2.4

708 .23 2.8

710 .24 3.3

712 .26 3.8

714 .27 4.3

716 .29 4.9

718 .32 5.5

720 .38 6.2

722 34.6 39.0

724 58.4 133

726 76.6 267

728 95.6 438

730 121 656

732 143 921

734 163 1,230

736 184 1,570

738 210 1,970

740 227 2,410

742 245 2,880

744 262 3,390

745 273 3,650

746 282 3,930

747.3 301 4,310

748 309 4,520

750 355 5,190

Table 3. Differences in reservoir area and 

capacity (volume) at specified elevations 

between 2005 and 2008 bathymetric surfaces. 

[Reservoir spillway elevation 750.3 feet; elevation 747.3 feet is 

water-surface elevation during 2005 survey; elevations referenced 

to North AmericanVertical Datum 1988 (NAVD 88)]

Elevation, 

in feet

Area, 

in acres

Capacity, 

in acre-feet

692 -0.13 -0.03

694 -.14 -.30

696 -.13 -.57

698 -.10 -.81

700 -.07 -1.04

702 -.06 -1.12

704 -.03 -1.22

706 0 -1.24

708 .02 -1.18

710 .06 -1.14

712 .08 -1.00

714 .68 -.49

716 4.15 3.02

718 14.5 21.3

720 28.3 63.3

722 13.1 105

724 9.9 128

726 11.6 150

728 14.9 177

730 12 203

732 9 219

734 11 240

736 27 280

738 28 330

740 31 390

742 29 450

744 30 510

745 28 540

746 27 570

747.3 21 600

748 21 610

750 3 620

Figure 2. Data-collection points for lower 

Taum Sauk Reservoir survey, 2008.

Figure 1. Bathymetric contours of lower Taum Sauk Reservoir, June 16–19, 2008.

Figure 5. Change in the June 16–19, 2008, bathymetric surface from the December 20–22, 2005, bathymetric surface for lower 

Taum Sauk Reservoir.

Figure 4. Data-collection points for lower 

Taum Sauk Reservoir survey, 2005.

Figure 3. Bathymetric contours of lower Taum Sauk Reservoir, December 20–22, 2005 (modified from Rydlund, 2006).

Location of lower Taum Sauk Reservoir in Reynolds County, Missouri.