Now a little more than 18 months after the H-5 dam gate at Lake Wood failed, the Friends of Lake Wood group is asking Guadalupe-Blanco River Authority (GBRA) for answers.
According to GBRA Assistant Manager Jonathan Stinson and Engineering Project Manager Charlie Hickman, Lake Wood is one of many problematic gates, all built in the 1920s and 1930s, in the GBRA Hydroelectric System.
Hickman talked about the gate failure. He passed out a handout similar to the one distributed in March, with H-5 schematics and the inner workings of the existing non-functioning weir dam, explaining the mechanisms involved in the operation of the dam, as well as those involved in the failure.
According to Hickman the dam gate is constructed with two leaves: one each for upstream and downstream. The downstream side rolls on top of the upstream side and the gate is raised by pressure.
"What happened here is the downstream side of that section blew out and we lost the ability to pressurize that gate so the gate went down," Hickman said.
Hickman said the upstream side of the gate was so bent out of shape after the failure GBRA's engineers do not view repair as possible. He also said the other gate is on the verge of failure. The H-5 hydroelectric facility remains offline.
"You cannot affordably repair what's out there," Hickman said. "You would actually spend more time and effort trying to straighten out all that steel and put it back into shape than it would take to just build a new gate from scratch; so, we've ruled out repairing the structure at all as a feasible option."
Hickman said from the beginning GBRA enlisted engineers to put together a scope of work and cost figures. They have also asked for the design of a dewatering system to keep water off the upstream side of the gate and a backup locking system to prevent future gate failures.
According to Hickman, GBRA has moved past the initial research and development phase of the project and is currently in the design and engineering phase.
GBRA has looked at a number of dam gate options, including a Labyrinth Weir, a Hydraulic Crest Gate; and, the Obermeyer Gate with replacement cost ranging from $2.9 million all the way to $4.5 million for the one gate. Hickman said it would be prudent to replace both gates together given the age and condition.
A big obstacle for GBRA is funding. In March, former Chief Financial Officer Alvin Schurig reported on the funding aspect of hydroelectric system repairs.
Schurig said the 86-year-old hydro system includes: six dams and 15 spill gates; six power houses and nine turbines/generators; two canals and headworks; approximately 22 miles of transmission lines; and approximately 18 transformers.
Back in March, Schurig had said GBRA purchased the system from Texas Hydro-Electric Corporation and the Texas Power Corporation in 1963, for $3,750,000. During the 54 year-year existence of GBRA and the Guadalupe Valley Hydro Electric System additional system investments total $10,043,066. In the same time period maintenance and repairs to the system have totaled $24,644,185. In 54 years the net revenue to GBRA has totaled just $1,620,165. As of August of last year the financial position of GBRA GV Hydroelectric Division was $72,378 in available cash; zero external debt; an inter-fund loan debt from the GBRA General Division of $4,301,357. Hydroelectric power sales account for 98 percent of the division's funding.
The project is yet unfunded. $2.4 million earmarked for the rehab – before the failure – has been redirected to the rehab of other dam gates in the GBRA system.
According to GBRA, a similar update will be provided for the GBRA board of directors at the board's Nov. Meeting, on Wednesday, Nov. 15.