OMAHA, Neb. — The bloated Missouri River rose to within 18 inches of forcing the shutdown of a nuclear power plant in southeast Nebraska but stopped and ebbed slightly Monday, after several levees in northern Missouri failed to hold back the surging waterway.
The river has to hit 902 feet above sea level at Brownville, Neb., before officials will shut down the Cooper Nuclear Plant, which sits at 903 feet, Nebraska Public Power District spokesman Mark Becker said.
Flooding is a concern all along the river because of the massive amounts of water that the Army Corps of Engineers has released from six dams. Any significant rain could worsen the flooding especially if it falls in Nebraska, Iowa or Missouri, which are downstream of the dams.
The river is expected to rise as much as 5 to 7 feet above flood stage in much of Nebraska and Iowa and as much as 10 feet over flood stage in parts of Missouri. The corps predicts the river will remain that high until at least August.
Becker said the river rose to 900.56 feet at Brownville on Sunday, then dropped to 900.4 feet later in the day and remained at that level Monday morning. The National Weather Service said the Missouri River set a new record Sunday at Brownville when its depth was measured at 44.4 feet. That topped the record of 44.3 feet set during the 1993 flooding.
The Cooper Nuclear Plant is operating at full capacity Monday, Becker said.
The Columbus-based utility sent a "notification of unusual event" to the Nuclear Regulatory Commission when the river rose to 899 feet early Sunday morning. The declaration is the least serious of four emergency notifications established by the federal commission.
"We knew the river was going to rise for some time," Becker said Sunday. "It was just a matter of when."
The nuclear plant has been preparing for the flooding since May 30. More than 5,000 tons of sand has been brought in to construct barricades around it and access roads, according to the Nebraska Public Power District.
The Army Corps of Engineers said the river level at Brownville had surged about 2 feet from Saturday morning to Sunday morning and that it continued to rise because of heavy rain on the Nishnabotna River, which flows into the Missouri River from Iowa, and due to some erosion along a levee upstream at Hamburg, Iowa, that created a water pulse.
The Cooper Nuclear Station is one of two plants along the Missouri River in eastern Nebraska. The Fort Calhoun Station, operated by the Omaha Public Power District, is about 20 miles north of Omaha. It issued a similar alert to the regulatory commission June 6.
The river has risen at least 1.5 feet higher than Fort Calhoun's 1,004-foot elevation above sea level. The plant can handle water up to 1,014 feet, according to the Omaha Public Power District. The water is being held back by a series of protective barriers, including an 8-foot rubber wall outside the reactor building.
Its reactor already had been shut down for refueling and maintenance since April, and it won't be turned on again until the flooding subsides.
The entire plant still has full electrical power for safety systems, including those used to cool radioactive waste. It also has at least nine backup power sources.
A spokesman for the Nuclear Regulatory Commission said the commission thinks the Omaha Public Power District managers have "done everything that they need to do to respond to the current conditions" at the nuclear plant.
Over the weekend, several northern Missouri levees failed to hold back the raging floodwaters, and the hole in a Holt County levee that ruptured last week continued to grow.
Recent rain increased the amount of water in the already swollen river, and floodwaters from the breached levee south of Hamburg, Iowa, rushed back into the river over the weekend through a notch cut in the levee south of the last week's break.
The floodwater in Missouri has covered thousands of acres of farmland and soaked numerous homes and cabins. The recreational community of Big Lake, which is home to a state park and less than 200 people, is being threatened by the floodwater.
Most of Big Lake's residents have already evacuated. The area 78 miles north of Kansas City has been high for the past couple weeksand has experienced major flooding in three of the last five years.
Associated Press writers Nelson Lampe and Josh Funk contributed to this report from Omaha, Neb.