SALMON, Idaho (Reuters) - Rising waters forced evacuations in Minot, North Dakota, on Tuesday as officials in South Dakota raced to finish levees to protect the state capital and other cities from the swollen Missouri River.
Mandatory evacuations over the next couple of days are expected to displace 10,000 to 12,000 Minot residents as the Souris River, a tributary of the Red River, eclipses records set in damaging floods of 1976 and 1969, officials said.
Communities along the Upper Missouri River basin also are bracing for flooding as officials plan historic water releases to relieve pressure on six reservoirs from Montana through South Dakota from heavy rains and a thick melting snowpack.
Residents of North Dakota’s capital, Bismarck, were working with state National Guard troops to fill and place thousands of sandbags to hold back the Missouri River.
Water releases from the Garrison Dam above Bismarck and adjacent Mandan reached record levels on Monday. Authorities went door-to-door there to encourage people to leave.
Contractors have been racing to complete levees in the South Dakota capital of Pierre and nearby Fort Pierre before federal officials increase water flows from a reservoir nearing capacity upstream on the Missouri River from those cities.
South Dakota Governor Dennis Daugaard said construction of levees was on track to reach planned levels within two days in the capital and in Dakota Dunes, a small town near the Iowa border, but said residents should be prepared for the worst.
“I am hopeful that we will be able to complete the reconstruction and elevation of existing levees, add additional levees where necessary and protect the residential areas in Dakota Dunes. But we cannot count on that,” said Daugaard, who toured Dakota Dunes on Tuesday.
The Missouri River is expected to rise about 8 feet from current levels at Dakota Dunes when water flows are brought to maximum releases from the Gavins Point reservoir by mid-June. Officials are planning two feet of buffer on the levees.
The pace of releases is expected to gradually increase this week but then step up after the weekend, eventually not quite doubling already high levels to make space in the reservoirs for additional water flowing in from the rains and thaw.
“We are hovering right around our record pool right now,” said Eric Stasch, U.S. Army Corps of Engineers operations manager at the Oahe Dam above Pierre.
The high water in the Columbia and Missouri basins comes after major flooding already this year of the Mississippi River in the Midwest and south to the Gulf of Mexico.
‘WE‘VE NEVER BEEN THROUGH THIS’
Pierre and Fort Pierre residents have been bracing for days as contractors push to extend levees to meet the high waters.
“Every house has bunkers around it,” Pierre resident Steve Halvorson said in a telephone interview.
Halvorson, 46, who has lived 19 years in Pierre, said his house is high enough up to be protected from the rising waters, but he has brought in generators and checked sewer lines to prepare for the flooding.
“It’s sobering to see what’s been done and we don’t even know if it’s going to be effective because we’ve never been through this,” he said.
Rain over the long holiday weekend forced water managers to boost their controlled releases from reservoirs that control Missouri water levels faster than previously planned.
Governors from Montana, the Dakotas and Wyoming have called up hundreds of National Guard soldiers to bag sand, assist in levee building and try to dissuade anxious property owners from navigating submerged roads and washed-out bridges.
Emergency workers also have been ferrying food and water to the small Montana town of Roundup, cut off by rising floodwaters on the Musselshell River.
About 500 people have been displaced by flooding on rivers in the Missouri and Columbia basins in Montana that has also washed out bridges and damaged roads. High water also has been blamed for two deaths and the disappearance of a boater.
Montana Governor Brian Schweitzer said on Tuesday the flood fight will continue for weeks with the bulk of a record mountain snowpack yet to melt.
“It’s probably going to get worse before it gets better,” Schweitzer told reporters, adding that the state will soon reach thresholds required for a federal disaster declaration that allows local governments to seek aid in rebuilding.
In Colorado, warm temperatures forecast for this week have officials worried that a rapid thaw of snowpack levels almost 250 percent of average could cause flooding in several areas.
The National Weather Service issued a flood advisory on Tuesday for the north-central mountains as high water flows from the Colorado River are expected as temperatures rise.
Minor flooding already hit the mountain town of Steamboat Springs in northwestern Colorado on Tuesday, Bob Struble, emergency manager for Routt County, told Reuters.
Struble said 10 inches of water is standing in the parking lot of a Steamboat Springs hotel, some 30 miles from the headwaters of the Yampa River at its confluence with the Elk.
Reporting by Ann Nachtigal in Sioux Falls, South Dakota; Laura Zuckerman in Salmon, Idaho; and Keith Coffman in Denver; Writing by David Bailey; Edited by Dan Whitcomb and Peter Bohan