Crews Inspect Gavins Point Dam For Damage After Summer Flooding
YANKTON, SD —
If you visited Gavins point Dam Wednesday you may have done a double take: no water was flowing out of the dam.
It was a far different sight than last summer, Wednesday the water was 23 feet lower than at the peak of last year's flood.
Gavins Point Dam was built in 1957, now after almost sixty years, and all the water that flowed through it because of last year's flooding, crews were checking the dam for damage.
It's something you don't see every day.
A dam that's completely dry.
"We are at a zero flow today at Gavins Point Dam," said Dave Becker, Operations Project Manager for the Gavins Point Project with the US Army Corps of Engineers.
The empty spillway in Yankton was a far cry from what you would have seen there last year.
At the height of 2011's flood water was flowing through the spillway at more than 160,000 cubic feet per second.
"Where we lived we could hear the water gushing out," said Sonya Wattier, a Yankton resident who was at the dam Wednesday. "It was so loud at our house living out here."
That historic rush of water is why crews were out here Wednesday, checking the dam for damage.
"It's amazing that there's all that water behind them and they're brave enough to stand down there," said Merrel Pepper of Sioux Falls, as he watched the crews working on the spillway.
Few people have seen that spillway as dry as it was Wednesday, but the problems crews were looking for are in a place we can't see. There's a layer of gravel underneath the concrete.
"We found that we had a void in some of that gravel under that concrete," said Becker.
Crews are checking the two foot thick concrete pad and the four feet of gravel beneath it to see how much the rushing water washed away.
They were using ground penetrating radar and probing a bit further down as well.
"We are drilling some test holes through the concrete so we can stick some rods down into the gravel and really check the condition of that gravel," said Becker.
They were giving the dam a safety check and letting folks see it in a way they might never see again.
"I've never seen it this low for all the years I've lived up here and stuff, but we never saw it as high as it was last year either, though," said Wattier.
It's all about getting Gavins Point ready in case "Mother Nature" ever decides to let the Missouri River loose again.
The Missouri will be lower in Sioux City Thursday, but not by much.
Flow out of the dam will go up to 28,000 cubic feet per second,a normal amount for this time of year.
Any repairs that are needed should be repaired by June or July.