Corps Sets Missouri Basin Flood Storage Plan for Fall and Winter
The U.S. Army Corps of Engineers, which is still sending above-normal releases from its six Missouri River dams, does not plan to increase its flood storage capacity this fall and winter because of risks to downstream levees.
Brig. Gen. John R. McMahon, commander of the Corps’ Northwest Division, says the planned release schedule announced July 29 will allow the Corps to get its system ready for the 2012 season when it starts March 1.
“We came to the conclusion that this year we would not need additional flood control space,” he says.
That came after considering several factors, including peoples’ need to return to flooded homes, farms and businesses; weather forecasts for this fall and winter; risks from continued high water on saturated levees; the need to inspect and repair dams and damaged infrastructure, and the need to release water in Kansas reservoirs.
Record snowfall and rain in May created runoff that peaked at 72.8 million acre-feet in a system that was designed to handle 40 MAF, McMahon says.
The planned step-down Missouri releases will ease river flow. At Gavins Point Dam, near Yankton, S.D., the release dropped from a record 160,000 cubic ft per second — a rate held since June 24 — to 155,000 cfs July 30 and 150,000 cfs Aug. 1. It will fall to 40,000 cfs Sept. 30 and 20,000 cfs Dec. 1.
The other dams, all upstream, have already started reducing releases.
Based on that schedule, the Missouri should be back in its banks by mid-September at Omaha and late September or early October at Rulo, Neb., says John Remus, Omaha District chief of the hydrologic engineering branch.
“It took a month to fill the flood plain, and will take at least that long to drain it,” McMahon says.
The risk to levees continues as long as water is high, he says.
“We have serious concerns about how the levees are performing,” especially after the stress from 2010 flooding, he says.
“We have observed many problems with them — animal holes, boiling, seepage," McMahon says. "We’re very concerned. “[Levees] are acting as dams, and they are not designed to be dams, they are designed to be levees.”
“The longer we prolong high levels of water on them, the greater risk of them failing.”
Corps experts also need to get into the dams — which all have held and released record amounts of water — for evaluations and repairs, which McMahon wants started by Dec. 1.
States, cities and counties, with highways, roads and bridges under water since mid-June, will also need to assess and repair those.
Elected officials in the eight-state Missouri Basin have been critical of the Corps, and the governors will meet with Corps officials Aug. 19 in Omaha.
In Iowa, where 148,565 acres are flooded, Gov. Terry Branstad (R) “believes it’s vitally important to keep our priority focus’’ on the flood fight, spokesman Tim Albrecht says.
“One of the goals [of the Aug. 19 meeting] will be to increase our focus on flood management,” he says.
“Gov. Branstad believes a review of the management of the Missouri River is absolutely critical to the long-term future of the state.”
