J. B. Thomas Reservoir - 2015 Survey Report

Prepared by John Clayton and Charles Munger
Inland Fisheries Division – Amarillo District

This is the authors' summary from a 23-page report. For a copy of the complete report, use the download link in the sidebar.

Fish populations in J.B. Thomas Reservoir were surveyed in 2015 using electrofishing and trap netting and in 2016 using gill netting. Historical data are presented with the 2015-2016 data for comparison. This report summarizes the results of the surveys and contains a management plan for the reservoir based on those findings.

Reservoir Description

J.B. Thomas Reservoir is a 7,820-acre impoundment (constructed in 1952) on the Colorado River. The dam is located 16 miles southwest of Snyder and west of State Highway 208, in Scurry County, Texas. The reservoir is owned by the Colorado River Municipal Water District (CRMWD) and provides water to three member cities. The reservoir has a drainage area of 3,950 square miles; however, it experiences frequent water level fluctuations, and the reservoir was last full in 1962. The reservoir declined steadily from approximately 3,917 acres in 2005 to 320 acres in 2012 due to drought and municipal water pumping. In 2014 and 2015 the watershed experienced large rain events, and the reservoir increased in size to 6,233 acres and was 3 feet below Conservation Pool elevation (approximate 46 foot rise). Angler access is good as most of the shoreline is accessible, and currently two of four boat ramps are open and usable. At the time of sampling, habitat consisted primarily of sand/silt and rocky shore covered with flooded terrestrial vegetation and standing timber.

Management History

Important sport fish include Largemouth Bass, White Crappie, and catfishes. Florida Largemouth Bass were introduced in 1980. Due to extended drought followed by a recent large rise in lake level, Blue and Channel Catfish were restocked in 2015. Florida Largemouth Bass were stocked in 2015 and 2016. The sport fish populations have only been managed with statewide regulations.

Fish Community

• Prey species: Gizzard Shad were highly abundant in the reservoir, and the majority of sampled shad were available as prey to most sport fish. Electrofishing catch of Bluegills was low, and no Bluegill over 4-inches in length were observed.
• Catfishes: The 2015 stocking of Blue Catfish appears to have been successful with numerous juvenile fish sampled. Blue Catfish greater than 20 inches were also observed. The Channel Catfish population also appears to be recovering from the extended period of drought; both juvenile fish as well as legal sized fish were sampled. Flathead Catfish are present in the reservoir.
• Largemouth Bass: The 2015 stocking of Largemouth Bass fingerlings occurred approximately 3 months prior to the 2015 electrofishing survey. As there was little time for the fish to grow and disperse throughout the lake, few bass were observed. All fish sampled were below the minimum length limit.
• White Crappie: Few White Crappie were observed, and only one legal-sized fish was collected.

Management Strategies

Conduct monitoring with trap nets, gill nets, and electrofishing in 2017-2018 to evaluate the continued recovery of sportfish populations following the extended drought and recent water level rise. Contact CRMWD about developing parking area at White Island boat ramp. Continue educating the public about the dangers of invasive species.

Performance Report as required by Federal Aid in Sport Fish Restoration Act Texas Federal Aid Project F-221-M-6 Inland Fisheries Division Monitoring and Management Program