Calaveras Reservoir - 2011 Survey Report

Prepared by John Dennis and Randy Myers
Inland Fisheries Division
District 1-D, San Antonio, Texas

This is the authors' summary from a 36-page report. For a copy of the complete report, use the download link in the sidebar.

Fish populations were surveyed using electrofishing and gill nets during the 2007-2012 study period. An annual creel survey and a vegetation survey were also conducted. This report summarizes the results of the surveys and contains a management plan for the reservoir based on those findings.

Reservoir Description

Calaveras Reservoir is a 3,110-acre power plant cooling reservoir located southeast of San Antonio. A near-constant water level was maintained by pumping from the San Antonio River during periods of low rainfall and runoff. Angler access and recreational facilities are managed and maintained by Thousand Trails Management Services and include two boat ramps, a handicapped accessible fishing pier, a fish cleaning station, and multiple picnic, camping, and restroom facilities. Both boat ramps were renovated in 2007. Aquatic plant coverage in the reservoir was <2% of the total surface area. Exotic blue tilapia and armored catfish populations have become well established in the reservoir.

Management History

Important sport fishes included red drum, palmetto bass, and blue and channel catfishes. The red drum and palmetto bass populations were maintained by stocking, with palmetto bass stockings occurring every year since 2004 and red drum stockings every year since 1993 except 2005. Northern largemouth bass (NLMB) have been stocked to increase genetic diversity; however stocking success was short-lived. Hybrid and sub-adult white crappies were stocked to re-introduce the species to the reservoir; however a self-sustaining population was never established. Orangemouth corvina and Orangemouth corvina x speckled trout hybrids were stocked to provide an additional sport fish; however that program was discontinued. Angler harvest of all sport fishes, except largemouth bass and red drum, was regulated according to statewide size and daily bag limits. A minimum size limit of 18 inches and a 3-fish daily bag limit was implemented in 1990 for largemouth bass and harvest of red drum was restricted by a 3-fish daily bag and 20-inch minimum size limit.

Fish Community

• Prey species: Gizzard shad, threadfin shad, and bluegill were the primary prey species and are present in sufficient numbers and sizes for utilization by predators.
• Catfishes: The reservoir contained abundant populations of channel and blue catfishes which supported a popular fishery. Blue catfish abundance is increasing.
• Palmetto bass: Population abundance varied somewhat from year to year. However, the stockings have provided a consistently popular fishery for this species.
• Largemouth bass: Population abundance remained low and this species supports a limited fishery.
• Red drum: This introduced species supported a popular fishery and abundance increased markedly between 2007 and 2012.

Management Strategies

Continue to stock palmetto bass and red drum to support these popular fisheries. Change largemouth bass minimum length limit from 18 inches to the statewide minimum length limit of 14 inches.

Performance Report as required by Federal Aid in Sport Fish Restoration Act Texas Federal Aid Project F-221-M-2 Statewide Freshwater Fisheries Monitoring and Management Program