Gov. Mark Dayton declared a state of emergency Thursday in dozens of counties swamped by torrential rains, flash flooding and high winds.

"These severe summer storms, which began on June 9, 2018, have caused significant flooding and damage to public infrastructure and property in 36 Minnesota counties and one Tribal Nation," the governor's office said.

Included in the order are: Aitkin, Becker, Beltrami, Blue Earth, Brown, Carlton, Cass, Clearwater, Cottonwood, Faribault, Fillmore, Freeborn, Jackson, Kittson, Lake, Lyon, Mahnomen, Martin, Mille Lacs, Mower, Murray, Nicollet, Nobles, Pine, Pipestone, Polk, Red Lake, Redwood, Renville, Rock, Sibley, Stearns, Stevens, St. Louis, Waseca and Watonwan counties, as well as the Red Lake Nation.

On Thursday, water levels along the Cottonwood River in southwestern Minnesota started to recede after hitting a record 19.85 feet in Lamberton, but residents in cities downstream such as New Ulm and Mankato braced for rising waters.

The New Ulm Police Department closed Cottonwood Street as water from the Cottonwood River swelled. The river is expected to hit major flood stage at 18 feet by Friday, according to the National Weather Service.

All that water will make its way into the Minnesota River and will pose a threat to Mankato by Monday, Henderson by Tuesday and Jordan by Wednesday, said weather service meteorologist Michelle Margraf.

"Where the heaviest rain fell, it's going to take a long time to drain," she said. "It's going to be a several-day process as water heads downstream before things start to recover."

Big storms this week dumped 8 to 10 inches of rain in Murray, Brown, Redwood and Cottonwood counties, pushing rivers and streams out of their banks and to "some of the highest levels we've seen," she said. Residents can check river levels and forecasts on the National Weather Services' web page.

Normally, southwestern Minnesota sees about 5 inches of rain during the month of July. "They got double that in one day," Margraf said.

With the ground already saturated by earlier rains, the water just ran off, filling basements and farm fields, she said.

Twenty-three counties had declared states of emergency due to damage sustained from river flooding or severe thunderstorms since mid-June.

Flood warnings remained in effect along the Cottonwood River at New Ulm and along the Minnesota River in Henderson, Jordan and Savage in the south metro. The Minnesota River will rise to near 706.5 feet by next Thursday, which is 4½ feet above flood stage, the weather service said. At that level, water will begin to cover Black Dog Road in Burnsville and roads and trails at Fort Snelling State Park.

The Cottonwood River is expected to crest at 17.9 feet in New Ulm, about 7 inches over flood stage by early Friday. Flooding is not expected to threaten homes or businesses, New Ulm police officer Eric Gramentz said.

Margraf advised no recreation on the high-running and fast-flowing rivers. Motorists are advised not to drive through standing water. New Ulm police warned drivers that it is too hard to know how deep the water is and whether the road is even there.

The short-term forecast is promising: No significant rain is expected through the weekend.

"We are grateful for the dry weather," Margraf said.

Tim Harlow • 612-673-7768