Lady Bird Lake - 2007 Survey Report

Prepared by Stephan J. Magnelia and Marcos J. De Jesus
Inland Fisheries Division
District 2-C, San Marcos, Texas

This is the authors' summary from a 25-page report. For a copy of the complete report, use the download link in the sidebar.

Fish populations in Lady Bird Reservoir were surveyed in 2007 using electrofishing and in 2008 using gill nets. This report summarizes the results of the surveys and contains a management plan for the reservoir based on those findings.

Reservoir Description

Lady Bird reservoir is a stable-level, 469-acre impoundment of the Colorado River located in the city of Austin, Travis County, Texas. Prior to 2007 the reservoir was named Town Lake. The reservoir runs through the mid-section of the city and was constructed in 1960 for purposes of flood control, municipal and industrial water supply and recreation. The reservoir also serves as a cooling source for steam-electric power generation and is owned and operated by the City of Austin (COA). The reservoir lies within the Edwards Plateau ecological area and has shoreline length of 18.3 miles and a drainage area of approximately 38,240 square miles. Some of the adjacent land has been developed into city parks. Other shoreline areas have been developed by private businesses.

Management History

Important sport fish included largemouth bass and channel catfish. Largemouth bass were managed under a 14-inch minimum length limit until September 1, 2000 when a 14- to 21-inch slot length limit was initiated. Prior to this more restrictive length limit harvest may have been limited due to a fish consumption advisory. The Florida subspecies of largemouth bass was stocked in 1998 to improve trophy largemouth bass potential.

Fish Community

• Prey species: Small Lepomis sp. continued to be the dominant forage species, although small gizzard shad were present in the 2007 survey.
• Common carp: Catch-and-release common carp (Cyprinus carpio) fishing is a popular activity on this reservoir, but little relative abundance data has been collected on this species.
• Catfishes: The channel catfish population continued to have few fish available to anglers. Previous attempts to supplement the channel catfish population through stocking were unsuccessful. Flathead catfish were present in low density.
• Largemouth bass: Largemouth bass were abundant. Past creel surveys indicate most anglers fishing the reservoir target this species. Population size structure was good. Individuals exceeding the upper end of the slot length limit (21 inches) were collected in the last three electrofishing surveys.
• Triploid grass carp: Triploid grass carp (Ctenopharyngodon idella) were first documented in the reservoir in 2007. These fish probably escaped from Lake Austin, which is directly upstream, where grass carp were used to control the aquatic plant hydrilla (Hydrilla verticillata).

Management Strategies

The reservoir's fish population should continue to be managed with existing regulations. Aquatic vegetation should be annually monitored to: 1) detect the presence of hydrilla; and, 2) the influence of triploid grass carp emigrating from upstream Lake Austin on the aquatic plant community. Additional information should be collected on the triploid grass carp and common carp populations.

Performance Report as required by Federal Aid in Sport Fish Restoration Act Texas Federal Aid Project F-30-R-33 Statewide Freshwater Fisheries Monitoring and Management Program