Releases of water from Gavins Point Dam were cut back over the weekend and they’ll be cut back even further later this month. Officials with the U.S. Army Corps of Engineers say the historic flooding on the Missouri River was unavoidable. Corps Brigadier General John McMahon insists no one could have adequately prepared for what happened this spring.
“What caught us off guard this year was not predictable,” General McMahon says. “It was a tremendous, historic amount of rain that nobody anticipated and it set new records going back 114 years.” Releases from the dam were cut from 160,000 cubic feet per second to 150,000 over the past few days, and the releases will be further cut to 90,000 in a few weeks.
Given the heavy rain and the melting snowpack, McMahon defends the Corps’ management of the river, saying natural events beyond anyone’s control created the flood. “Certainly, the system was not designed to accommodate the event of 2011,” he says. “That’s well-documented with over 46-million acre feet of runoff between March and July. The system was designed to handle 40-million acre feet, based on the 1881 flood. So, that’s an example of the dynamic that’s at play here.”
McMahon says once the upstream flows drop enough, the Corps will begin inspecting levees and preparing for the 2012 season. The Corps’ Engineering Chief John Bertin says though the levees all along the Missouri River are under extreme pressure, they have been holding back the floodwater for weeks.
“They’re performing fairly well,” Bertino says. “We had some issues that were identified early. We worked with the sponsors and the states to correct those issues. Anytime you have water on a levee, you have risk and we’re trying to address that.” While water flows are being reduced, the flooding will be slow to recede. Some estimates indicate it may be into October before the Missouri is back at normal, pre-flood levels.
With the cutback in water releases into the Missouri River, the city of Council Bluffs suspended sandbagging operations today. Spokesman Don Gross says groundwater levels will remain high in Council Bluffs, causing problems for the next several months.
“We’ll have as this event goes on just more basement collapses, more flooded basements and more personal, private,” Gross says. “It’s kind of an invisible crisis. It’s very visible for the person who lives in the home, but you could drive by and you wouldn’t know.” Gross says the decision to stop sandbagging was not prompted by the reduction in water being released upstream, from the Gavins Point Dam in South Dakota.
The city has about 90,000 sandbags filled, enough meet current needs, according to Gross, plus the number of sand-bag volunteers has declined because of the heat.