Lake Austin is a popular fishing and boating destination. The lake is considered to have an excellent stock of large-mouth bass, however, the lake is considered best utilized for pleasure boating during the day.
Lake Austin has been stocked with several species of fish intended to improve the utility of the reservoir for recreational fishing. Fish present in Lake Austin include largemouth bass, catfish, and sunfish. Lake Austin is one of the Texas Highland Lakes infested with hydrilla, a non-native aquatic plant species. The Lower Colorado River Authority has intentionally lowered the water levels in the lake in the months of January and February so that freezing air temperatures might destroy substantial portions of the hydrilla in the lake each winter.