USA- The Guadalupe-Blanco River Authority (GBRA) in Texas is discussing how to mitigate safety risks to recreationalists downstream of four low-head dams that impound water for hydroelectric plants.
One option being considered is lowering the level in these four lakes — McQueeney, Placid, Meadow and Gonzales — by up to 12 feet.
GBRA experienced spillgate failures at Lake Wood in 2016 and Lake Dunlap in May 2019. The Lake Wood incident was caused by failure of structural steel members inside the gate. The Lake Dunlap incident resulted in dewatering of the lake, which has a storage capacity of 5,900 acre-feet. The board of directors voted this week to conduct additional engineering inspections at Lake Dunlap in an effort to identify the cause and point of failure of the spillgate collapse and how that information can be applied to the gates at the other dams.
These six dams were built in the late 1920s and early 1930s and are at the end of their useful life. Each provides water to a hydropower facility.
“While no decision was made today regarding the best way to ensure public safety on the lakes, GBRA’s concerns remain,” said Kevin Patteson, GBRA general manager. “The video of the Dunlap spillgate collapse validates our concerns, and we are not willing to risk lives should there be another spillgate failure.”
GBRA says it will continue to work with county and state law enforcement to identify public safety strategies that can be implemented to reduce the risk of danger to recreationalists. Ample public notice will be provided prior to any changes to lake level elevations.
The authority announced in June that “all repairs to the hydroelectric dams are indefinitely postponed until a determination can be made on how the work can progress safely.”
GBRA was established by the Texas Legislature in 1933 as a water conservation and reclamation district. GBRA provides stewardship for the water resources in its 10-county statutory district.