"Aging structural steel” is believed to have caused equipment to fail at a 91-year-old dam, which prompted Lake Dunlap to drop to alarmingly low levels, the Guadalupe-Blanco River Authority said Thursday evening.
The authority said it’s committed to finding a way to replace spill gates at all its aging dams but noted that this depends on its ability to secure funds for the improvements, which will cost millions of dollars.
The trouble at Lake Dunlap, an 8-mile long waterway east of New Braunfels, occurred at 7:49 a.m. Tuesday when a middle spill gate failed, unleashing a large volume of water that virtually drained the lake.
What caused the failure is still under investigation, but the river authority released a statement Thursday evening saying it believes that “aging structural steel” played a role.
A similar spill gate collapse occurred in 2016 at Lake Wood, 4 miles west of Gonzales, after structural steel inside that gate failed.
“We recognize the value of Lake Dunlap to the community,” Guadalupe-Blanco River Authority General Manager Kevin Patteson said in the statement. “The ability to move forward with construction at Lake Dunlap, Lake Wood and the other dams is dependent on securing funding for these multiyear, multimillion-dollar projects.”
After the Lake Wood incident, the river authority consulted engineers on how to best repair or replace spill gates in the hydroelectric system. It ultimately decided to replace all aging spill gates with a more modern gate system.
Last year, the river authority began designing hydraulic crest gates for Lake Wood. It’s proceeding with a design that will involve replacing the spill gates and making changes to the dam’s concrete structure. That design will take about a year to complete. Similar modifications are planned for other dams overseen by the river authority, including at Lake Dunlap.
Construction will take two to three years at each site. The costs are projected to be about $15 million to $35 million per dam.
“GBRA’s revenues alone cannot support that level of investment,” the river authority’s statement noted. “GBRA is continuing to research all available funding opportunities through state and federal resources, as well as stakeholder partnerships.”
Source: San Antonio Express News