HELENA – The spring melt after a winter of heavy snow is causing waterways in northern Montana to swell over their banks, putting several areas at risk of flooding, meteorologists said.
The water is rising fastest in the northeastern part of the state, near where the Milk and Missouri rivers meet. In that area, gravel roads have gone under and some houses have been surrounded by the rising water, said Tanja Fransen, warning coordination meteorologist for the National Weather Service in Glasgow.
“Valley County and the confluence at Nashua is the concern right now,” Fransen said Friday.
The Milk River at Glasgow is expected to reach 31.4 feet by Sunday. The weather service says it could cause moderate flooding.
In other places, the river is expected to keep rising through next week.
It’s expected to reach higher than 28 feet by Thursday at Tampico, which could cause major flooding. By next Saturday, it’s expected to hit 29 feet at Nashua, a foot above the weather service’s moderate flood category.
The Milk River is expected to keep rising on the next few weeks, and there is no final crest in the forecast at this point, Fransen said.
The region usually gets about 30 inches of snowfall each year, but some parts of northeastern Montana saw as much as 105 inches this winter, the Great Falls Tribune reported.
The Army Corps of Engineers has been working to reinforce a levy in Nashua to protect the town from the Milk River and Porcupine Creek drainages, the newspaper reported. The levy there has been raised to 31.6 feet, which is an inch shy of the predicted “worst-case scenario,” when floodwaters would reach 31.7 feet.
Upstream, the threat of flooding is not as imminent, though the river is rising.
The Milk River at Harlem was at 16.5 feet Friday and expected to rise to 21.1 feet by midweek, which is just above flood stage, Fransen said.
But those communities should still be prepared.
“There’s a lot of snow to melt,” Fransen said.