Updated

MINOT, N.D.-- The Souris River's full weight hit Minot on Friday, swamping an estimated 2,500 homes as it soared nearly 4 feet in less than a day and overwhelmed the city's levees. City officials said they expected as many as 4,500 homes to be severely damaged by the time the river peaks Saturday.

More than a quarter of the city's 40,000 residents evacuated earlier this week, packing any belongings they hoped to save into cars, trucks and trailers.

"The river's coming up rapidly," Mayor Curt Zimbelman said. "It's dangerous and we need to stay away."

Fed by heavy rains upstream and dam releases that have accelerated in recent days, the Souris surged past a 130-year-old record Friday and kept going. The river was more than 5 feet above major flood stage Friday afternoon and expected to crest as early as Saturday evening some 8 1/2 feet beyond major flood stage.

The predicted crest was lowered a foot based on new modeling by the National Weather Service, but it was little consolation in Minot.

"This has been a very trying time for our community," Zimbelman said. "It's emotionally draining for all of us."

As they had the past two days, emergency officials focused on protecting water and sewer systems to avoid the need for more evacuations. They were confident about the water system, but a little less so about the sewer treatment plant. It had been sandbagged as high as possible.

Zimbelman said water coming up through a storm sewer briefly began to erode one downtown levee before it was controlled.

Also of concern was the Broadway Bridge, a key north-south route. Levees protecting the northern approach were being raised, but Army Corps of Engineers Lt. Col. Kendall Bergmann said it was touch and go. The levee work also protected the campus of nearby Minot State University.

Members of the state's congressional delegation pressed for a federal emergency declaration making people eligible for individual assistance, a step they said was needed for the Federal Emergency Management Agency to set up transitional housing centers.

Sen. John Hoeven said a helicopter flight over the Souris valley showed damage to smaller cities nearby. He estimated more than 5,000 homes in the valley would eventually have water damage, including those in Minot and Burlington, where officials gave up sandbagging Thursday. The Army Corps of Engineers was leading an effort to build emergency levees in Velva, a small town about 20 miles downstream of Minot, before the Souris crests there Tuesday.

In Burlington, deputy auditor Cindy Bader estimated Friday that more than half of the town's 1,000 residents had left to escape the rising Souris River.

Burlington's city hall, school and police and fire departments appeared safe, but some homes in the evacuation zone had water up to their first floors and higher. In one neighborhood, the tops of two traffic signs barely peeked above the brown, brackish water, which reached just beneath the eaves of two nearby houses.

Wayne Walter, a Burlington city councilman and truck driver for a snack food company, said residents were stunned by the river's rapid rise.

"When we went to bed last night, and when we got up this morning, it was a big difference," Walter said Friday. "Down by the dikes, we saw it just trickling over (Thursday night). This morning, everything was gone."

Walter said he lived across the street from the evacuation area, and the Souris was still about 4 feet from his own home.

"Right now, we're staying there, but we've got the camper packed," he said. "They tell us to leave, we're gone."

The National Guard had 870 members activated for the crisis. Minot is best known as home to an Air Force base, which oversees 150 Minutemann III missiles in underground launch silos scattered over 8,500 square miles in northwest North Dakota.

Col. S.L. Davis, commander of the 91st Missile Wing, said there was some "localized flooding" at a handful of missiles sites because of the wet spring and summer. But he said the silos are designed to safety handle some water and protective measures were taken at a few sites similar to what's done in preparation for spring runoff from snowmelt.

In Minot, a car parked near the Broadway Bridge was dry Friday morning but submerged by midday. Nearby, about a half-dozen gophers found themselves stranded in a small and shrinking dry patch. Furniture store workers cheered as one of the gophers swam 20 yards to safety.

The U.S. Fish and Wildlife Service launched four boats to patrol flooded neighborhoods and respond to 911 calls, but no injuries were reported and no rescues were necessary. The evacuation zone was empty except for emergency officials and some geese, who paddled in about 5 feet of water washing down the streets.

George Moe, 63, whose house was about a block from the water's edge, returned briefly Friday to pick up some keys. Moe said the only thing left in his house was the mounted head of an antelope shot by his wife, who died about three years ago.

Moe worried about the home he's lived in for four decades and the shop where he works as a mechanic; it was taking on water and he wasn't sure he'd have a job after the flood.

"I hate to see something go to hell after 40 years," he said. "There ain't much you can do."