Floodwaters are still rising in the US Midwest and are not expected to crest for another 24 hours, forecasters sat, after three people died in Nebraska and Iowa.
The Missouri River, the longest in North America, has flooded much of Nebraska between Omaha and Kansas City at the Missouri state line. It was expected to crest at 14.48 metres on Tuesday, breaking the previous record, set in 2011, by more than a foot, the Nebraska Emergency Management Agency (NEMA) said in the latest bulletin on its web page.
"This really is the most devastating flooding we've probably ever had in our state's history, from the standpoint of how widespread it is," Nebraska Governor Pete Ricketts said in a Twitter post on Monday.
"In 2011, it took 108 days for water to subside, and this year the water is 4-5 feet higher," Ricketts said in another tweet. "NEMA and teams across the state are working around the clock to provide relief."
Ricketts and Iowa Governor Kim Reynolds have both declared states of emergency, and US President Donald Trump said the White House had reached out to state and local officials in devastated areas.
On Monday the Omaha World-Herald newspaper, citing sheriffs' officials, reported that an 80-year-old woman had become the latest confirmed fatality of the disaster. Betty Hamernik died in her home near Columbus, Nebraska, after becoming trapped by rising floodwaters from the Loup River.
Other casualties identified by local authorities are 50-year-old James Wilke, who was swept away while trying to use his tractor to free a trapped car near Columbus, and a man whose car was caught up in fast-moving water in Iowa..
At least two people are missing in Nebraska, the World-Herald reported.
More than 600 Nebraska residents were evacuated and taken to American Red Cross-operated shelters, NEMA said on Sunday.
The Missouri River's overflowing banks have cut off roads leading to the Cooper nuclear plant, near Brownville, Nebraska, forcing operators to fly in staff and supplies by helicopter. The nuclear plant continued to operate safely and was at full power, its operator said.
Water also covered one-third of that state's Offutt Air Force Base, near Bellevue, home to the US Strategic Command.
Australian Associated Press