Granbury Reservoir - 2021 Survey Report

Prepared by Michael S. Baird and John Tibbs
Inland Fisheries Division
Waco District

This is the authors' summary from a 29-page report. For a copy of the complete report, use the download link in the sidebar.

Fish populations in Granbury Reservoir were surveyed in 2021 using electrofishing and in 2022 using gill netting. Historical data are presented with the 2021-2022 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

Granbury Reservoir is an 8,700-acre impoundment located near the City of Granbury, Hood County, Texas and is operated by the Brazos River Authority (BRA). Primary water uses include storage of flood and storm waters, municipal water supply, power plant cooling, and recreation. Fish habitat at the time of sampling consisted mainly of bulk heading, natural shoreline, boat docks and piers and emergent aquatic vegetation (Giant reed, Cattail and American water willow). Water level averaged one foot below conservation pool during the 2021-2022 vegetation, electrofishing, and gill netting surveys (Figure 2).

Management History

Important sport fish include Largemouth Bass, Channel Catfish, White Bass and Striped Bass. Sport fishes in Granbury Reservoir are currently managed with statewide regulations. In 2013, management efforts began focusing on supporting the statewide public relations campaign “Clean. Drain. Dry” and posting appropriate aquatic invasive species (AIS) signage at access points to try and prevent the spread of zebra mussels into the reservoir. In 2016, the BRA funded a cooperative effort to build and deploy fish attracting structures (i.e., 28 crappie condos and 16 Mossback Safe Haven structures) near mid-reservoir, to begin to enhance fish habitat reservoir wide. The 16-inch minimum length limit on Largemouth Bass was changed back to the statewide, 14-inch minimum length regulation on September 1, 2018, during a statewide effort to simplify Texas Largemouth Bass regulations. Recent management efforts include aquatic vegetation and boater access surveys conducted during summer 2021 and gill netting during spring 2022.

Fish Community

• Prey species: Forage species including Threadfin and Gizzard Shad, Bluegill, Longear Sunfish and Redear Sunfish, were present in the reservoir in low to moderate abundance. Nearly half of the Gizzard Shad were available as prey to predators.
• Catfishes: Channel Catfish were abundant and body condition improved with increasing size; most were of legal length. Blue Catfish and Flathead Catfish were present in low numbers.
• Temperate basses: White Bass were available and body condition was good across length classes; most were of legal length. Striped Bass catch improved and body condition across all length classes was excellent. Most of the Striped Bass observed were of legal length also.
• Largemouth Bass: Largemouth Bass were collected in below average numbers and body condition varied greatly among length classes. Good percentages of legal fish were still available to anglers yet young of the year fish made up a large proportion of the population.
• White Crappie: White Crappie were available and most collected fish were of legal length. Body condition was excellent.

Management Strategies

• Continue managing Granbury Reservoir with existing regulations.
• Conduct monitoring surveys with fall electrofishing in 2025 and spring trap netting and gill netting surveys in 2026 (Table 8).
• Conduct aquatic vegetation and access surveys in late summer 2025 (Table 8).
• Continue efforts to educate the public about AIS issues and protect the reservoir from zebra mussel introductions.
• Continue stocking Striped Bass annually and coordinate with the BRA on future artificial habitat projects pending funding and reservoir priorities.

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