U.S. DEPARTMENT OF THE INTERIOR Prepared in cooperation with the WATER-RESOURCES INVESTIGATIONS U.S. GEOLOGICAL SURVEY DEPARTMENT OF TRANSPORTATION AND DEVELOPMENT REPORT 99-4217 PUBLIC WORKS AND FLOOD CONTROL DIRECTORATE BATHYMETRIC SURVEY AND PHYSICAL AND WATER RESOURCES SECTION CHEMICAL-RELATED PROPERTIES OF LAKE

ACE, IN FEET

INTRODUCTION 0 94° 05´ 00´´ 94° 02´ 30´´ 94° 00´´ 93° 57´ 30´´

ATER SURF 2 Caddo Lake, located in northwestern Louisiana and Hunts Cr OW W northeastern , is a popular recreational lake used for water- CADDO LAKE 4 0 1.0 MileNorth eek based activities such as fishing, boating, and swimming. Caddo 3632000 0 6 Lake is a source of drinking water for several small Louisiana 1.0 Kilometer communities surrounding the lake. The latest (1994) available 2 Line of equal depth of water, August and September 1998 DEPTH BEL 8 estimates of water withdrawn from the lake by public suppliers are (water-surface elevation 167.58 feet above sea level). Marion Dashed where approximately located. Interval 2 feet. County as follows: the Blanchard Water System, 0.695 Mgal/d (million 10 Boat channel 1 Sampling site gallons per day); the Vivian Water System, 0.413 Mgal/d; Caddo and number Caddo Water District 1, 0.222 Mgal/d; the Mooringsport Water System, Main channel Parish 12 A Boat ramp

0.113 Mgal/d; the East Mooringsport Water System, 0.17 Mgal/d; 3630000 and the East Cove Utility Water System, 0.042 Mgal/d (P.M. Study Area A 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,00020,00018,000 Johnson-Thibaut, U.S. Geological Survey, written commun., LOUISIANA SURFACE AREA, IN ACRES 1998). An understanding of current hydrologic conditions of TEXAS N 140 Caddo Lake and other lakes and in Louisiana is

essential to the management and protection of these valuable A 2 natural resources. Water quality and quantity are important ACE, IN FEET

I concerns to those who use these lakes and reservoirs for INDEX MAP 4

3628000

municipal, recreational, agricultural, or industrial purposes. S

Current and accurate information regarding the physical and 32° 47´ 30´´ 6

I

ATER SURF chemical-related properties and conditions of freshwater lakes and W reservoirs in Louisiana is fundamental to planners and managers 8

U OW for evaluating these resources. In October 1996, the U.S. S 538 Geological Survey, in cooperation with the Louisiana Department 10 of Transportation and Development, began a study to conduct a O

A 3626000 12

DEPTH BEL bathymetric survey and determine the physical and chemical- LOUISIANAL

related properties of Caddo Lake. X 0 20,000 40,000 60,000 80,000100,000

The purpose of this report is to present the results of the E 1 bathymetric survey and the results of vertical profiles of physical Figure14 2. Depth-surface area and depth-volume relations for Caddo Lake. and chemical-related properties, including depth, water TEXAST Water-surface elevation was 167.58 feet above sea level during the temperature, dissolved oxygen (DO), specific conductance, and bathymetric survey of August and September 1998. 2 3624000 pH. Hydrographic surveying software was used for combining 4 VOLUME, IN ACRE-FEET differential global positioning system (DGPS) information with 0 digital survey fathometer data to accurately map the bathymetry of 6 10 FEET 2 the lake. The bathymetric map was produced using geographic 32° 45´ 00´´ 8 information systems (GIS), and lines of equal depth of water were 4 reviewed and edited for accuracy and consistency. On-site ACE, IN 6 physical and chemical-related properties were measured at three 8

SURF 2 3622000 selected locations using a water-quality monitor. This report is 4 2 6 10 one in a series of planned map reports describing current ATER

W 12 bathymetry and physical and chemical-related properties of lakes 2 C 14

6 OW and reservoirs in Louisiana. 727 4 16

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Description of Study Area 6 DEPTH 20 8 3620000 8284 86 88 90 283 4 5 6 7 2 22 WATER TEMPERATURE, IN DISSOLVED-OXYGEN CONCENTRATION, Caddo Lake (fig. 1), which is about 20 miles northwest of 10 8 DEGREES FAHRENHEIT IN MILLIGRAMS PER LITER 27 feet 2 Shreveport, Louisiana, is located in northwestern Caddo Parish, 0 2 deep Louisiana, and western Marion County, Texas. A 1997 census 2 FEET 2

32° 42´ 30´´ 2 10 estimated a population of 200,827 for Shreveport, 244,943 for F E D 4 4

E, IN 2 0 8 2 8 2 Caddo Parish (Northeast Louisiana University, Uniform Resource B 6 IG 4 4 6 A AC

C 3618000 Locator accessed December 1, 1998), and 10,635 for Marion YP 2 8 RE 6 8 S 6 County, Texas (U.S. Bureau of the Census, URL accessed S 4 4 8 SURF BA 6 2 8 1 10 September 16, 1999). This area has a subtropical transitional YO U 6 Willow Pass ATER 12 climate with a mean annual rainfall of 46.1 inches and a mean 6 8 3 B W

o W 14 annual temperature of 65.2 F (degrees Fahrenheit) (Jay Grymes, 8 4 Twelvemile

O Louisiana Office of State Climatology, written commun., 1998). 16

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1 3616000 20 Caddo Lake has a drainage area of 2,744 square miles. The DEPTH lake receives inflow from in Texas and Hunts 4 125130 135 140 145 6.5 7.0 7.5 8.0 8.5 Creek in Louisiana, which enter at the western and northern ends, 22 SPECIFIC CONDUCTANCE, IN G pH, IN STANDARD UNITS respectively, and numerous other smaller tributaries. Water level 169 20 miles southeast MICROSIEMENS PER CENTIMETER 2 538 to Shreveport AT 25 DEGREES CELSIUS is controlled by a 3,725-foot-long spillway located at the eastern B Site 1 2457 Site 2 end of the lake in Louisiana. Water discharges into Willow Pass Site 3 Twelvemile Bayou. The spillway originally completed in 1914 32° 40´ was rebuilt in 1971; the crest elevation of the spillway is 3614000 Figure 3. Variation of water temperature, dissolved-oxygen concentration, specific conductance, and pH in Caddo Lake, August 12, 1998. 168.00 feet above sea level. The maximum design discharge is Aerial photomap by the U.S. Geological Survey 396000 398000 400000 402000 404000 406000 36,000 cubic feet per second (Ray Elifami, Louisiana Department Figure 1. Bathymetry of Caddo Lake, August and September, 1998. Color infrared photographs Caddo Lake, Roll 95040, October 15, 1995 of Transportation and Development, written commun., 1998). depth data were obtained to comprehensively describe the lake average depth of Caddo Lake was 4.6 feet, with depth of 4.6 feet or ranged from approximately 85 to 83oF (fig. 3). Northeast Louisiana University, Center for Business and Economic Caddo Lake is a very wide shallow lake; shallower areas of bathymetry; 154,959 data points of latitude, longitude, and depth were greater over more than 50 percent of the lake-surface area. Greatest Research, Louisiana parishes and municipalities July 1, 1997, the lake are densely vegetated and impassable to motorized boats. recorded. The bathymetry of Caddo Lake is shown in figure 1; all water depths are located in the eastern part of the lake east of the Highway population estimates published in January 1996: accessed December Active and abandoned oil well pumping station platforms and The DO concentration profiles were fairly uniform with depth, depths are referenced to the August 10-13, 1998, water-surface 538 bridge, where the water depth is approximately 27 feet. 1, 1998, at URL http://leap.nlu.edu/POPHS/pop1997.txt remnant pilings of decayed platforms are scattered throughout the with only site 1 showing a slight decrease in concentration with depth. elevation of 167.58 feet above sea level. lake. Well-demarcated channels allow boat traffic to avoid At site 1, DO concentrations decreased from 5.16 to 3.26 mg/L at U.S. Environmental Protection Agency, 1976, Quality criteria for water: submerged obstacles and the densely vegetated areas. PHYSICAL AND CHEMICAL-RELATED approximately 3 feet, then varied slightly with depth. For sites 2 and 3, Washington, D.C., U.S. Environmental Protection Agency, 256 p. shallow-water DO concentrations ranged from 6.90 to 7.09 mg/L, and Equipment used during the bathymetric survey included a PROPERTIES varied slightly with depth. Concentrations of DO vary considerably -----1986, Quality criteria for water: Washington, D.C., U.S. Starlink DNAV-212 DGPS, an Odom digital survey fathometer, and Acknowledgments with depth, location, and season (Demas, 1985). The criterion for DO Environmental Protection Agency [variously paged]. HYPACK software. The DGPS measured spatial position in latitude Data on physical and chemical-related properties were is 5 mg/L for freshwater aquatic life (Louisiana Department of and longitude with routine accuracy of 5 feet; horizontal control points collected on August 12, 1998, at selected sites in Caddo Lake. At Environmental Quality, 1998, p. 128; U.S. Environmental Protection The author extends appreciation to Zahir “Bo” Bolourchi, were established at the beginning and rechecked at the end of each these sites (1, 2, and 3 in fig. 1), multiple points along a vertical profile Agency, 1976; 1986). Water visibility, measured with a Secchi disk, Chief, Water Resources Section, Louisiana Department of survey day to maintain that accuracy. The survey fathometer measured were sampled to establish the occurrence and depth of stratification. was 1.0 feet. Transportation and Development, for direction and assistance the depth with routine accuracy of 0.1 foot; the fathometer was The HYDROLAB, a water-quality monitor, was calibrated at the provided for this study. Thanks are given to the National calibrated at the start and verified at the end of each survey day to In this report, “sea level” refers to the National Geodetic Vertical Datum beginning of the day prior to physical and chemical-related property Research Center of the U.S. Geological Survey, maintain that accuracy. The HYPACK software was used for survey The specific conductance varied slightly; shallow-water of 1929--a geodetic datum derived from a general adjustment of the first-order data collection. µ Lafayette, Louisiana, for providing background aerial planning, survey execution, and storage and editing of data. Data were concentrations ranged from 143 to 137 S/cm (microsiemens per level nets of both the and Canada, formerly called Sea Level photographs. exported to ARC/INFO for drawing lines of equal depth of water and centimeter at 25 degrees Celsius). The pH ranged from 8.0 to 6.73 Datum of 1929. subsequent reviewing and editing of the results. Data were collected along a vertical profile from above the lake (standard units) near the surface, and varied only slightly with depth. bed to 1.6 feet below the water surface. Data were recorded at a Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. BATHYMETRY maximum depth of 19.7 feet at site 1 and 7.2 feet at sites 2 and 3. Surface area and volume spatial analyses also were performed Temperatures decreased from 88 to 85oF within 3 feet of the surface REFERENCES within ARC/INFO. The water-surface area of Caddo Lake was at site 1; however, water temperatures were uniform throughout the 18,700 acres, and the water volume was 85,100 acre-feet. The depth- Bathymetric data for Caddo Lake were collected during water column at sites 2 and 3. Shallow-water temperatures ranged Demas, C.R., 1985, A limnological study of Lake Bruin, Louisiana: surface area and depth-volume relations are shown in figure 2. The August 10-13 and September 1-2, 1998. Accurate position and from 88oF to approximately 83oF, and bottom-water temperatures Louisiana Department of Transportation and Development, Office of Public Works Water Resources Technical Report no. 38, 96 p.

Louisiana Department of Transportation and Development - U.S. Geological Survey Water Resources Cooperative Program Bathymetric Survey and Physical and Chemical-Related Properties of For additional information contact: Copies of this report can be purchased from: District Chief U.S. Geological Survey ON AND D TI EV Caddo Lake, Louisiana and Texas, August and September 1998 U.S. Geological Survey Branch of Information Services TA E R L O O 3535 S. Sherwood Forest Blvd., Suite 120 Box 25286 P P S M Baton Rouge, Louisiana 70816 Denver, Colorado 80225 N E

N By Paul A. Ensminger

A E-mail: [email protected] Telephone (toll free): (888) ASK-USGS T R

T DOTD Telephone: (225) 389-0281

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O Fax: (225) 389-0706

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