MINNEAPOLIS (Reuters) - The Missouri River, which has been pressing flood defenses from Montana to Missouri for more than three months, was expected to return to normal water flows by early October, U.S. officials said on Tuesday.
"Barring any significant rain events during the next month, river levels are expected to return to normal in portions of the Missouri River in early October," the U.S. Army Corps of Engineers said in a statement.
The Corps oversees water flows from six key dams on the Missouri River from Montana to the South Dakota-Nebraska border which were overwhelmed earlier this year by a massive and melting snowpack and heavy rains in May.
Water releases from the six dams were double previous records along the Missouri, forcing thousands of residents from their homes and communities to erect miles upon miles of new levees or beef up existing defenses.
The Corps has begun a gradual reduction in the water releases and the bulk of the remaining floodwater stored in the reservoir system should be cleared by early December, it said.
Officials only now are getting a close look at flood damage as waters recede, including a segment of interstate destroyed between Omaha, Nebraska, and Council Bluffs, Iowa. Deep holes have been found in some Missouri roads, and sinkholes have been found under city parks in Pierre, South Dakota's capital.
The Missouri River basin forms the northwest bowl of the vast Mississippi River system that stretches from the Rockies to western New York, funneling water down through Louisiana and into the Gulf of Mexico.
The runoff over the last four months has been immense. The volume of water runoff from May through August was greater than the total annual runoff in all but three years since the Corps began keeping detailed records in 1898: 1997, 1978 and 2010.
The Corps aims to reduce the stored flood water as quickly as possible to prepare for next year's snow melt. It must reduce water levels gradually to allow water-logged levees and banks time to dry out slowly and prevent collapse.
(Reporting by David Bailey; Editing by Jerry Norton)