Colorado Parks & Wildlife outlines Lake Avery dam repairs, plans to drain and rebuild outlet this summer

Colorado Parks and Wildlife officials told the Rio Blanco County Board of Commissioners at a public hearing April 8 that they drained Lake Avery last fall to allow inspection and will begin repair work on the Lake Avery dam outlet this summer.

Jonathan Lambert, CPW local-area wildlife manager, and colleagues described the repairs as necessary after inspections and camera work inside the outlet pipe revealed cracks and a leaking head gate. CPW has measured inflow and outflow and said it will match throughflow so the stilling pool near the outlet does not send excess sediment downstream. Construction is tentatively scheduled to begin late June or early July, once peak runoff subsides, and CPW said the target was to complete main work by late fall. If unexpected delays occur the reservoir will remain drawn down until repairs are complete.

CPW said it already staged a fish-salvage operation when it lowered the lake, removing more than 300 adult black crappie to Rio Blanco Reservoir and allowing public anglers to take fish while the lake was lowered. The agency said when the dam work is finished it will complete a lake-management plan in coordination with the Upper Colorado River Recovery Program and partners, study Big Beaver Creek to assess fish movement and native cutthroat status, and then determine what trout stocking is appropriate once the lake refills.

Commissioners and members of the public questioned how CPW will manage sediment and turbidity downstream during construction; CPW said it installed a small stilling pool to capture sediment and will time releases to limit downstream impacts. County staff and nearby residents pressed CPW on monitoring and coordination; CPW said it measured pH and temperatures and had conducted water-quality checks during an earlier sediment release, and that the agency will pause or adjust releases if sediment loads become excessive.

Why it matters: Lake Avery is part of the White River watershed and downstream water quality and fish habitat are closely monitored. Repairs to the outlet and the need for sediment mitigation have direct implications for recreation, local ranching and downstream aquatic habitat. CPW said it will coordinate with the county on releases and asked the public to direct questions to CPW contact staff.

Provenance: CPW presentation and Q&A were recorded during the April 8 public hearing; commissioners asked for enhanced coordination and monitoring.