One of Utah's most popular hiking routes, the Virgin River Narrows in Zion National Park, is off-limits because of the strong spring runoff.

Elsewhere in the state, residents in Utah County and southern Utah continued sandbagging and other preparations against the rising waters.

Normally, rangers at Zion will not issue permits to hike through the narrows unless the flow of the Virgin River is 120 cubic feet per second or less. Now it's at 1,700 to 2,300 cfs, park spokesman David Eaker said in a telephone interview.

The river is swift and cold, at only 40 degrees. People walking toward it from the lower end, near the river walk, should take care because even venturing a short distance into the torrent could cause them to be swept away. Park officers are especially concerned about the many visitors during the hot Memorial Day Weekend, when they might be tempted to approach the river.

"We hope people just use common sense," he said. Eaker added that the river may not be low enough for safe hiking until July.

Statewide, no new serious flooding was reported Monday, as the spring runoff roared along.

"Our current warnings are for the Bear River near the town of Evanston (Wyo.) and the Sevier River and its tributaries," said Peter Wilensky of the National Weather Service forecast office. Most of the river stretches where warnings are in effect are agricultural land, although some roads and bridges could be damaged.

A flood watch, a less urgent rating, is in effect for the Logan River, American Fork River, Dry Creek (a tributary in Utah County to the American Fork River), the lower Weber River below Echo Reservoir, and for streams out the state's southwestern mountains. The streams include Coal Creek near Cedar City, the North Fork of the Virgin River and mountain streams above Beaver.

"All have potential to create problems," Wilensky said. "We're looking for the hot temperature to continue through much of the rest of the week," and for the snowmelt to continue.

"The melt is proceeding with good haste," Wilensky said. "It appears that the areas of concern are high and they're going to become a little higher."

In Utah County, bloated rivers, swollen from quickly melting snowpack and filled with debris, smashed through culverts and took out roads across Utah County as temperatures continued to rise Monday.

East of Spanish Fork, the Diamond Fork river pushed through a $10,000 steel culvert in the Diamond Fork Canyon, crumpling it like tin foil and pushing it away from the Three Forks bridge it was under, said Loyal Clark, spokeswoman for Uinta National Forest.