Army Corps Increasing Water Releases At Missouri River Dams

Jul 6, 2018

Credit US Army Corps of Engineers

Officials with the U.S. Army Corps of Engineers say above-normal water releases will continue this summer at dams along the Missouri River. 

Army Corps senior hydraulic engineer Kevin Stamm says the updated runoff forecast for this calendar year is 150 percent of average above Sioux City. 

He says last month's rainfall in the Dakotas, Iowa, Nebraska, and Montana coupled with melting mountain snowpack led to higher than normal runoff rates. 

"June runoff was about 160 percent of average in the Fort Peck reach, 190 percent of average in the Garrison reach, and over 300 percent of average in the Sioux City reach. Compared to the last 120 years of record, the Garrison June runoff volume ranked as the second highest June runoff volume. For the entire upper basin above Sioux City, the June runoff was the third highest in the last 120 years."

Joel Knofcynski with the Army Corps says releases are going up at Gavins Point Dam near Yankton. 

"Currently, Gavins Point releases are 42,000 cubic feet per second and will be increased to 60,000 cubic feet per second, and possibly higher, as downstream tributaries recede." 

He says there's 25 percent of reservoir storage available to collect additional flood waters. Knofcysnki says storage levels will peak about 4 million acre feet below the levels observed in 20-11. 

The forecast from the Army Corps shows releases at Gavins Point, Fort Randall, and Oahe Dams reaching 58,000 cubic feet per second by the end of the month. 

NOAA's Climate Prediction Center projects an equal chance of seeing above, normal, or below normal precipitation in most of the Missouri River basin through September. 

Parts of far western South Dakota and southeast Montana have a slight chance of seeing higher than average rainfall this month.