Colorado City Reservoir - 2012 Survey Report

Prepared by Mandy K. Scott
Inland Fisheries Division
District 1-C, San Angelo, Texas

This is the author's summary from a 13-page report. For a copy of the complete report, use the download link in the sidebar.

Fish populations in Colorado City Reservoir were surveyed in 2010 using electrofishing, and in 2011 using gill netting. The water level was too low to allow boat access during the report year 2012-2013. This report summarizes the results of the surveys and contains a management plan for the reservoir based on those findings.

Reservoir Description

Colorado City Reservoir is a 1,618-acre reservoir located on Morgan Creek, a tributary of the Colorado River, west of Colorado City in Mitchell County, Texas. Habitat consisted primarily of flooded terrestrial vegetation, native emergent vegetation, boulders and boat docks. The Morgan Creek Power Plant, that once used Colorado City as a cooling reservoir, closed down in 2008. After that the reservoir water level was not maintained at a near-constant level as it had been in the past. Colorado City Reservoir has been severely impacted by toxic golden alga (Prymnesium parvum) blooms every year since 2001 with fish kills occurring regularly. Shoreline access was good, including at the Lake Colorado City State Park, but boat access was not possible in 2012-2013 due to water level below the end of the boat ramps.

Management History

Historically, important sport fish included Largemouth Bass, White Bass, Channel Catfish, Blue Catfish, and Red Drum. Colorado City Reservoir has been impacted by toxic golden alga blooms, and a concerted effort was made to restock the reservoir when water quality was suitable. Florida Largemouth Bass (603,683) and Bluegill (863,965) were stocked during 2004-2008 and Channel Catfish (1,054,326) during 2003-2008. Reoccurrence of golden alga-related toxic conditions rendered these stocking efforts unsuccessful at re-building populations. As a result, all fish stocking in this reservoir has been suspended pending sustained improvements in water quality.

Fish Community

Only a few Common Carp were captured in the electrofishing survey, and no fish were captured in the gill netting survey.

Management Strategies

Based on current data, Colorado City Reservoir should continue to be managed with existing regulations. Future stockings are contingent on sustained improvements in water quality as determined by monitoring cell density and toxicity levels of golden alga. A mandatory standard survey is scheduled for 2016-2017 with gill nets and electrofishing to determine the status of fish populations.

Performance Report as required by Federal Aid in Sport Fish Restoration Act Texas Federal Aid Project F-221-M-3 Inland Fisheries Division Monitoring and Management Program