The Lower Colorado River Authority has completed a nearly two-year project to replace each of the floodgates at its Tom Miller Dam in Austin, Texas, with new floodgates that meet today’s engineering standards.
The original gates were installed during construction of the dam in the late 1930s.
“We undertook this project to help ensure we can continue operating the dam safely and reliably for generations to come,” said Phil Wilson, LCRA general manager. “This was a complex project, just as it was to build the dam some 80 years ago. To remove and replace each floodgate at a working dam was no easy task, especially when the dam is in the middle of Flash Flood Alley and needs to remain operational throughout the project.
“This project was important to help maintain the integrity and operability of our critical dam infrastructure. I’m proud to say we completed the project safely.”
Tom Miller Dam, which creates Lake Austin, has nine floodgates, but the most ever opened at one time is five. This happened twice — during Tropical Storm Hermine in September 2010 and the Halloween flood in October 2013. The dam impounds water that supplies a hydroelectric powerhouse with a capacity of 17 MW.
During the 22-month construction effort, Tom Miller Dam’s floodgates — each weighing 40,000 and 55,000 pounds — were disassembled one at a time and placed in sections on a transport barge to be taken off the lake for recycling. The new floodgates were fabricated in sections in Michigan, then assembled at the dam and installed.
LCRA operates and maintains the dam under a long-term lease with the city for the benefit of Austin and the people of Central Texas.
The project cost $10.8 million to complete. LCRA says it has invested more than $110 million in capital projects along the Highland Lakes, Lake Bastrop and Lake Fayette since fiscal year 2010. LCRA plans to invest about $64 million more in dam rehabilitation and maintenance over the next five years.
LCRA serves customers and communities throughout Texas by managing the lower Colorado River; generating and transmitting electric power; providing a clean, reliable water supply; and offering outdoor adventures at more than 40 parks from the Texas Hill Country to the Gulf Coast. The company produces electricity from coal, natural gas and hydro facilities. It operates six dams with hydroelectric facilities, with a total capacity at these six plants of more than 295 MW. LCRA was created by the Texas Legislature in 1934 and receives no state appropriations.