The Sioux City Journal posed some “What would it take …?” questions to officials today about area flooding. Here are the two questions that are most relevant to the Yankton area:
To raise the water level at Gavins Point Dam?
The water pool at Gavins Point Dam near Yankton, S.D., would have to increase by 3.6 feet to reach the top of the gates.
Jody Farhat, Chief of the Corps’ Missouri River Basin Water Management Division, said the dam’s reservoir level was at an elevation of 1207.4 feet Wednesday morning. The top of the gates is at 1210 feet.
“The pool is slightly higher than we like it,” she said. “We’d like it about a foot, maybe eight-tenths of a foot lower than it is now, but we’re not concerned about that.”
The corps has slowed releases from Fort Randall Dam near Pickstown, S.D., in order to lower the pool at Gavins Point. Releases at Fort Randall were held at 143,000 cubic feet per second Wednesday and are expected to be held to that amount again today before ramping up to the expected peak of 148,000 cfs.
To cause the corps to increase the release to more than the planned maximum of 150,000 cfs already being released from Gavins Point Dam?
The corps says it would take a lot of rain. How much, officials won’t or aren’t able to say.
Farhat said the corps would be forced to release more if “very heavy rains” fell across the upper Missouri River basin and filled up the rest of the storage in its six dams.
“Right now we don’t anticipate that happening,” Farhat said. “We’re looking at the forecast. We have the current rain built into that and also the snow (melt) and some cushion there. So, we’re pretty confident that we’re good at 150.”