Ice jams may cause Little Missouri flooding
As flowing subsides, car-sized ice chunks to stay behind
Low temperatures caused wet soil and the river to freeze solid, said Patrick Ayd, a National Weather Service meteorologist from Bismarck.
Because the ground was hard and saturated, what little precipitation the Little Missouri River Valley did receive melted into the river, Ayd said. The water began to lift and break the ice in recent weeks, causing large chunks of ice break up and then come back together, clogging and backing up the river, causing flooding. Though southwest North Dakota saw little snow over the winter, flooding could become an issue as the river flows north into Lake Sakakawea through the weekend.
“For the little bit of snow that we had, it seems like every drop made it into the river,” Ayd said.
The entire stretch of the Little Missouri is full of large chunks of ice — some as big as a car — that has to make its way down river as the water twists and turns through the prairie, Ayd said.
“It kind of piles up and slows down and takes a while for that to break free and then it floats down the river and gets jammed up again,” Ayd said. “Basically, we have significant ice problems from Bowman County all the way up towards Medora, and those problems will be spreading further north towards Lake Sakakawea.”
Sandi and Joe Frenzel of Dickinson own a cattle ranch along the Little Missouri between the South and Elkhorn Ranch units of Theodore Roosevelt National Park. There was an ice jam just north of their property, but all of the buildings are high enough that they aren’t too worried about any damage, Sandi said.
“The house is high enough,” Sandi said. “In 2011 it went through the lower cow pasture and horse pasture right below the house, but the house is high enough so I think we’re safe.”
Regardless, she was heading north Thursday afternoon to monitor the situation.
“We’ve already started calving, so we want to be sure there’s no issues,” Sandi said.
There isn’t much precipitation in the forecast, Ayd said. Flows will slow down and leave large chunks of ice to melt, but it could take a while, he said. The threat of flooding is expected to subside with lower flows.