YANKTON, S.D. – The Gavins Point Dam, operated by the U.S. Army Corps of Engineers, Omaha District, reached a milestone earlier this fall when six draft tube bulkhead gates at the hydroelectric powerhouse were replaced for the first time ever.
The gates date back to 1957 when construction of the dam was completed. They were refurbished once in the 1980s but have not been updated since. Each one is essential to maintaining the hydropower units.
“They’ve reached the end of their lifecycle, so it was time to replace,” said Martin Goding, Gavins Point powerhouse superintendent. “When we go into annual maintenance, they drop these gates, and there are men behind these gates, so it keeps the water out so we can actually do the maintenance on the inside of the unit.”
The gates are situated on the tailrace of the three hydropower generators where water from the Missouri River is channeled once it exits the unit.
The multi-day removal and installation project required patience and some heavy lifting. Each gate weighs 38,000 pounds and had to be moved one at a time by a gantry crane to the closest position within reach of a mobile crane before being lifted out by contracted crane and rigging professionals. Once removed, installation of the new gates was completed in the same manner.
With installation and leakage testing complete, Gavins Point Project mechanics and electricians have now begun annual maintenance on the three hydropower units scheduled for completion in April 2025.
The new gates will ensure maintenance of the hydropower units can continue for at least the next 50 years.
“If the old gates had failed, we would not be able to do the annual maintenance on the units,” Goding said. “Then we’re looking at potential failure of a component that we needed to do repairs to.”
The project cost $4.1 million and took 5 years to complete from design to finish.
Gavins Point Dam was built as part of the Flood Control Act of 1944. When not operating to reduce flood risk, it provides hydropower generation supporting 68,000 homes annually as well as water supply, water quality, irrigation, fish and wildlife conservation, navigation and recreational benefits.