Record flooding on the Missouri River two years ago did widespread destruction up and down the river, but it also did a lot of damage to several of the hydro-electric dams, including Gavins Point Dam in Yankton. Now the Army Corps of Engineers is in the middle of making millions of dollars in repairs.
The 2011 floods on the Missouri River were unprecedented.
"It was considered a 500-year event, so really a major event," Dave Becker of the U.S. Army Corps of Engineers said.
It's hard to tell just by looking at Gavins Point Dam, but the 50-year-old structure took a beating, mostly from floating debris.
"The heavy flows that we had for several months through the dam caused accelerated wear and tear on the dam," Becker said.
Crews removed 3,000 tons of debris that hit the dam hard. Plus, on the west side, the dam lost 75,000 tons of rock.
The Corps has already spent $2 million on improvements, like drilling holes into the concrete slabs to install pressure sensors.
"Our engineers over the years have had a little bit of concern about pressure under the spillway, slabs being too high causing uplift or heaving," Becker said.
Over the next two years, the Army Corps of Engineers will spend another $10 million on making structural repairs to the 14 gates on Gavins Point Dam.
The gates will be repainted, plus cables that open and shut them will be replaced.
"The debris did wear on them, plus it caused some gouging on the concrete wings walls below the spillway that we are taking care of just a host of things," Becker said.
But Becker says the dam is structurally sound.
"The dam is in really good shape and it really can take care of its business, but being a 50-year-old structure and having gone through the flood of 2011, we really want to do due diligence on this and make sure it's in good shape for the future," Becker said.