LCRA replaces first of 10 floodgates on Wirtz Dam
The first of 10 new floodgates (middle) is now in operation at Wirtz Dam, which separates Lake LBJ from Lake Marble Falls in Burnet County. The next of the floodgates to be replaced is on the right. Photo courtesy of LCRA
The Lower Colorado River Authority recently replaced the first of 10 floodgates on Wirtz Dam. The three-year project to remove and replace all floodgates on the structure that separates Lake LBJ from Lake Marble Falls is estimated to cost around $76 million.
The original nine floodgates were put in place when the dam was completed in 1951. A 10th floodgate was added when the Thomas C. Ferguson Power Plant was built in 1974.
“Most of the floodgates have been in place for 73 years, so it’s time for them to be updated,” said Kelly Payne, LCRA vice president of Water Operations. “We’re in a drought now, but we’re in Flash Flood Alley, and we know the next flood could be right around the corner.”
Weighing in at 120,000 pounds each, the custom-built floodgates are being constructed near the dam and then moved into place by barges and cranes. Wirtz Dam will remain operational as the project continues.
“It’s an exacting process to remove and replace floodgates on a working dam,” Payne said. “We gained valuable insight on the first floodgate that is proving to be helpful as we work on removing and replacing the remaining floodgates.”
Replacing rather than refurbishing the floodgates is faster and has the lowest safety and environmental risks, said the LCRA, which is also replacing the existing hoist bridge.
The project should be completed in 2025. During that time, the area up to about 300 feet upstream of Wirtz Dam on Lake LBJ will remain off-limits to boaters.
In October 2020, the LCRA finished replacing the nine original floodgates on Tom Miller Dam in Austin. In 2021, the authority completed a project to upgrade and rehabilitate each of the 37 floodgates at Buchanan Dam in Burnet County.
Since fiscal year 2010, the LCRA has invested over $165 million in capital projects at the dams along the Highland Lakes, Lake Bastrop, and Lake Fayette, including related hydroelectric generation infrastructure. LCRA plans to invest more than $101 million in similar projects over the next five years.