The Lower Colorado River Authority is beginning an 18-month project to remove and replace each of the nine floodgates at Tom Miller Dam in central Austin. The floodgates were installed during construction of the dam in the late 1930s.
The $9.9 million project continues LCRA's commitment to public safety and marks the second extensive renovation of the dam since it was completed in 1940. LCRA completed major structural improvements to the dam in 2005 as part of a dam modernization project.
"The dam is in excellent condition, but it's almost 80 years old,'' said John Hofmann, LCRA executive vice president of Water. "This project will replace the aging floodgates with new, custom-built floodgates that will help ensure the dam will continue to perform reliably and safely for generations to come."
Work on the dam, which creates Lake Austin, is expected to begin in mid-August. During the project, LCRA will replace one floodgate at a time. Work on each floodgate will take about six weeks. The dam will remain in service and available to respond to floods and water supply needs throughout the project.
"We need to keep the dam operational, and that was a key factor in developing plans for this project," Hofmann said. "We're in Flash Flood Alley, and we need to be able to react quickly to move floodwaters downstream at any time. Doing the work one floodgate at a time takes more time, but allows the dam to remain operational throughout the project."
Though Tom Miller Dam has nine floodgates, the most ever opened at any one time is five. This happened twice – during Tropical Storm Hermine in September 2010 and the Halloween flood in October 2013.
The project will involve the use of two barges – a large construction barge that will stay at the dam throughout the project and a smaller shuttle barge that will ferry the new floodgates and other equipment to the dam from behind LCRA's Jack Miller Building on Lake Austin Boulevard. The new floodgates will be fabricated and partially assembled in Michigan, then shipped to Austin via truck. They will be staged off-site until needed at the dam.
The steel in the original floodgates will be recycled. Each floodgate weighs between 40,000 and 55,000 pounds.
LCRA built the dam on property owned by the City of Austin. 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.
For more information on the project, visit lcra.org/tommillerdamproject.
The Lower Colorado River Authority serves customers and communities throughout Texas by managing the lower Colorado River; generating and transmitting electric power; ensuring a clean, reliable water supply; and offering access to nature at more than 40 parks, recreation areas and river access sites along the Texas Colorado River, from the Hill Country to the Gulf Coast. LCRA and its employees are committed to enhancing the lives of Texans through water stewardship, energy and community services. LCRA was created by the Texas Legislature in 1934. For more information, visit