MINNEAPOLIS (Reuters) - The swollen Missouri River breached another section of a southwestern Iowa levee on Thursday that has failed previously, forcing some evacuations and closing part of Interstate 29, authorities said.
Another section of the levee that breached early Thursday morning had failed several weeks ago, sending floodwaters rolling toward Hamburg, Iowa, where about one-quarter of its 1,200 residents were evacuated.
The breach on Thursday was one mile north of Percival, Iowa, about 15 miles north of Hamburg, and was expected to inundate more parts of Fremont County, Iowa, officials said. Most of the area is rural and has already had been evacuated.
The latest levee breach comes after several weeks of heavy water releases by federal officials to relieve pressure on six Missouri River reservoirs from Montana through South Dakota pressed to capacity by heavy snow melt and rains.
The U.S. Army Corps of Engineers has begun to pull back on water releases from several of the dams, but plans to maintain very high water releases for at least several more weeks.
The latest schedule has the Corps releasing water at peak projected rates of 160,000 cubic feet per second from Gavins Point Dam on the South Dakota-Nebraska border at least through July. That is well more than double the previous record rate.
The Missouri River runs freely from Gavins Point for more than 800 miles to the Mississippi River near St. Louis, making the maximum releases there a focus for residents downstream.
Water has pressed through or over levees in numerous places from Iowa through Missouri in the last several weeks, forcing evacuation of several smaller communities.
Flooding also has closed numerous roads and bridges, and waters have surrounded, but not inundated, the Fort Calhoun Nuclear Power station north of Omaha, Nebraska.
About 40 miles of I-29 was closed from Bartlett, Iowa, to the I-29/US 136 interchange in Missouri now because of Missouri flooding and another 16 mile stretch of the interstate is closed in the Council Bluffs, Iowa, area across from Omaha.
(Reporting by David Bailey; Editing by Jerry Norton)