H-4 (Gonzales) Reservoir 2019 Survey Report (PDF 1.2 MB)
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H-4 (Gonzales) Reservoir - 2019 Survey Report
Prepared by Greg Binion and Dusty McDonald
Inland Fisheries Division – Corpus Christi District
This is the authors' summary from a 34-page report. For a copy of the complete report, use the download link in the sidebar.
Fish populations in H-4 Reservoir were surveyed in 2019 using electrofishing, trap netting, and hoop netting and in 2020 using gill netting. Historical data are presented with the 2019-2020 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
H-4 is a 696-acre reservoir on the Guadalupe River in Gonzales County and is controlled by the Guadalupe-Blanco River Authority (GBRA). The reservoir was impounded in 1931 to provide water for hydroelectric generation and recreation. The substrate was primarily silt, sand, clay with some gravel and rock. Angler and public boat access are limited to one pay-to-use boat ramp and there are no handicap-specific facilities. Primary habitat is composed of boat docks and piers, timber, native floating-leaved and submersed vegetation, hydrilla, and water hyacinth.
Management History
Important sport fish species include Channel Catfish, Largemouth Bass, and crappie. Anglers have reported catching White Bass, Palmetto Bass, and Striped Bass from this reservoir, but these species have not been collected in any survey. Blue Catfish were stocked historically, but relative abundance remains low. The 2016 management plan focused on utilizing additional fishing gear methods to better assess declines in sport fish populations and continuing to assist GBRA with nuisance vegetation control.
Fish Community
- Prey species: Bluegill and other sunfishes formed the forage base for H-4 Reservoir. Bluegill catch rates have increased relative to 2017 with much of the population being smaller. Some Redear Sunfish did reach 8-inches and might provide decent angling opportunities. While Gizzard Shad are present, their catch rate has decreased and there are few available for predators within the reservoir.
- Catfishes: Channel Catfish catch rate increased since the last survey and the size composition was dominated by larger individuals with fish up to 29-inches collected. Blue and Flathead Catfish were present in low abundance. Flathead Catfish abundance has increased since previous surveys with fish reaching up to 30-inches with our survey.
- Largemouth Bass: Largemouth Bass fall electrofishing catch rate increased since 2017. Size composition was balanced and comprised of both juvenile and adult fish. One fish over 9 pounds was collected.
- Crappies: White Crappie catch rates have decreased since 2013 and abundance has remained low since. Black Crappie are present in the reservoir; however White Crappie is the predominant species.
Management Strategies
- Continue managing fish populations under current regulations.
- Continue to work with GBRA on controlling water hyacinth and hydrilla. Monitor the spread and expansion of water lettuce and East Indian hygrophila.
- Continue electrofishing, trap netting and gill netting to monitor population abundance of Largemouth Bass, crappies, and catfishes, respectively.
- Conduct a low-frequency electrofishing survey with appropriate settings to target Flathead Catfish to better assess population abundance and size composition.
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