KATHRYN, N.D. - National Guard helicopters dropped sandbags hoping to redirect water away from a small town where residents have been evacuated and National Guard soldiers posted to keep watch.

Officials said the Clausen Springs Dam would flood the town of Kathryn if it broke, prompting Wednesday's evacuation of the town's 55 residents while guardsmen went to work trying to shore up the dam and change the flow of water against it.

"That's slowing it (water) down, and they're going to try and channel it in a way that keeps it away from Kathryn," Gov. John Hoeven said.

Residents fled to relatives' homes or a Red Cross shelter after officials went door to door Wednesday morning telling them to get out. The Guard said it would send 32 soldiers to Kathryn for security.

Fire Chief Paul Fisher was on Kathryn's Main Street, using a two-way radio to monitor the flow of three culverts outside town. If they were to break, he said, "I'll make one more sweep through town and get out of here."

There was no evidence of major flooding by early afternoon, although some homes had water in their yards and signs of seepage in basements.

Kathryn is about 17 miles south of Valley City, which is battling record high water on the Sheyenne River. The Clausen Springs Dam is on a tributary of the river.

In Valley City, the elderly, disabled and people living in low-lying areas had been urged to evacuate by 6 p.m. Wednesday to make sure emergency routes were kept open. Mayor Mary Lee Nielson said that would affect about 1,450 homes _ "not quite half the city" of nearly 7,000 people.

Valley City got word Wednesday that the Army Corps of Engineers that it would be cutting back the amount of water it releases for two weeks from the Baldhill Dam north of the city.

"This is a lot of wear and tear on those dikes for two weeks," Nielson said. "We anticipate there's going to be some hot spots. But the good news is, hopefully it's just at that level."

Nielson said the evacuation was strongly recommended to avoid wear and tear on the city and clear the way for emergency and construction work. Valley City State University, with an enrollment of about 1,000, canceled its spring semester on campus, which has been torn up by dike work, and planned to offer courses online instead.

Nielson said she knows some people will stay in their homes but she hopes they will choose to leave.

"I told people in a nice way, 'If you don't have a reason to be here, to flush a toilet, leave,'" she said.

Fran Aune and her stepdaughter, Deb Wacha, were moving Aune's belongings out of her duplex Wednesday. Aune and her husband, Andrew, planned to set up a camper on a higher part of Valley City and wait out the floodwaters.

"It's scary," she said. "We've been praying a lot."

The Sheyenne empties into the Red River, which is expected to reach a second flood crest of its own near Fargo this week. The Red crested at Fargo and neighboring Moorhead, Minn., late last month just short of 41 feet, after volunteers filled thousands of sandbags to raise levees above that mark. Projections of the river's second crest have been lowered to around 35.5 feet to 36 feet.

Roads across North Dakota were flooded and travelers were warned regularly about delays or detours due to high water. Amtrak has suspended service between Minot and St. Paul, Minn., because of track flooding east of Minot.

A service of the Associated Press(AP)