Ice jams on the Salmon River are causing flooding concerns. The National Weather Service reports continued sub-zero temperatures in Lemhi County. The cold weather could mean the river will flood low-lying areas this week.
David Evetts is with the U.S. Geological Survey in Idaho. He says there is one ice jam north and one south of Salmon. Evetts says it’s common for ice jams to form in the area, but flooding isn’t always the end result.
“That upper ice jam if it moves or breaks," says Evetts, "it could release a fair amount of water down through the Salmon River and get backed up by the lower ice jam causing some local flooding.”
A campground north of Salmon has already flooded.
Local residents are used to seeing ice jams on the river. Mike Johnston owns the Salmon River Coffee Shop. He says people are aware of the dangers.
“[The ice] just keeps stacking up higher and higher," Johnston says. "It’s pretty amazing, really. When you see glaciers? That’s kind of what it is, just the width of the river.”
Northwest of Boise, an ice jam has formed on the Snake River. Evetts says that’s more unusual since the river is wider. He thinks the chances of reaching flood stage are less likely if the weather warms up this week.
Evetts says that in extreme cases, ice jams can be dangerous, if they stack up higher than a bridge and start moving quickly downstream.
Copyright 2013 Boise State Public Radio