The U.S. Army Corps of Engineers has picked today as the date to release a surge of water down the Missouri River. That “pulse” is intended to simulate the high water of spring runoff in an effort to encourage the endangered pallid sturgeon to increase in numbers. Corps spokesman Paul Johnston says it’ll begin late tonight.
At midnight Friday night, they’ll increase the releases of water from Gavins Point Dam, and keep it increasing through Saturday till reaching the full height of the “pulse,” 9-thousand cubic feet per second, and then start bringing it back down to minimum navigation levels on Tuesday.
This was supposed to be the second of two such events, but in March there wasn’t enough in the reservoir up-river to release any. That first pulse was designed to clean mud off the gravel beds the fish prefer, and the second when the weather warmed a bit was to give the sturgeon their cue to start the spawning process.
The Iowa Corn Growers Association sent a news release charging the Corps of Engineers with “choosing the potential interests of a fish over the certain needs of Iowans,” but no risk of flooding is expected from the “pulse” coming downstream this weekend. Johnston says the effect of drought hasn’t ended and the river’s still lower than normal.
The runoff for the year is still only 88-percent of normal, Johnston says, “so it’s too early to say that the drought is over.” He expects the pulse to raise the river at Sioux City and Council Bluffs by two to two and-a-half feet, but then the rise will taper off as the water’s flow moves on downriver into central Missouri. The Corps puts out a daily river-level forecast, and he says it shows the diminishing effect of the “pulse” in the river’s flow.
Kansas City when the pulse comes through will be a foot lower next week than it is today, he says, and just outside St. Louis, Missouri, the river will be four feet lower with the pulse in place than it is today. Johnston says passersby at Sioux City and Council Bluffs won’t be able to tell the pulse is passing down the river.