The failure of a spillgate at a 91-year-old dam in Texas this week is thought to have been caused by aging structural steel, although the official cause of the incident has not yet been determined.

The Guadalupe-Blanco River Authority (GBRA) announced it had experienced a spillgate failure at Lake Dunlap, in Guadalupe County, at approximately 7:49 a.m. on Tuesday, May 14, 2019. The failure resulted in the dewatering of Lake Dunlap and a video of the collapse has been widely circulated online.

In a statement, GBRA said it had experienced a similar spillgate collapse at Lake Wood, four miles west of Gonzales, in 2016 caused by a failure of structural steel members inside the gate. While the cause of the failure at Lake Dunlap will not be determined until further investigation, it is currently believed the failure at Dunlap is also related to aging structural steel.

“We recognize the value of Lake Dunlap to the community. GBRA is committed to finding a solution to replace the spillgates at all of our aging dams,” said GBRA General Manager Kevin Patteson. “The ability to move forward with construction at Lake Dunlap, Lake Wood, and the other dams is dependent on securing funding for these multi-year, multi-million dollar projects.”

After the gate failure at Lake Wood, GBRA engaged consulting engineers to determine the most feasible solution for repair or replacement of the spillgates in the hydroelectric system. The result of this analysis led to GBRA’s decision to replace all of the aging spillgates with a more modern gate system.

In 2018, GBRA began the design of hydraulic crest gates for Lake Wood, and is currently progressing with a design that will involve replacement of the spillgates along with modifications to the concrete structure of the dam. The design, which will take approximately a year to complete, will be similar for the other dams in the system, including at Lake Dunlap.

These improvements are expected to take two to three years for construction at each site, and require approximately $15-35 million per dam. GBRA’s revenues alone cannot support that level of investment and it said it is continuing to research all available funding opportunities through state and federal resources, as well as stakeholder partnerships.