Warm temps and melting snow raise ice jam concerns
By Jason Stuart
Ranger-Review Staff Writer
The rising temperatures and melting snows have state and local emergency preparedness officials on high alert as they keep a wary eye out for localized flooding and ice jams on the Yellowstone River.
“I have no idea what to expect, but there’s a lot of snowmelt coming down,” said Mary Jo Gehnert, Dawson County Disaster and Emergency Services coordinator.
With temperatures possibly reaching into the 50s this week and the mercury barely reaching the freezing point at night, Gehnert is currently most concerned about the potential for a sudden, violent break-up of the Yellowstone’s ice sheet.
Snow melting upstream of Glendive is currently pouring water into the river, though you can’t notice it below the crust of ice. Gehnert said the official river gauge in Glendive recorded a rise of over a foot in the river’s water level during a 24-hour period from Monday to Tuesday.
“It has risen on our gauge, so that’s letting me know there is some run-off coming down and it’s lifting the ice,” she said.
The surge of water entering the river combined with the warming temperatures is why Gehnert and other officials are keeping such a close watch on the Yellowstone. She noted it is those two factors working in concert which cause the ice to break up each spring.
And with a thick ice sheet on the river from a mostly brutal winter to date, the potential for major ice jams only increases.
“By all means (thicker ice can lead to worse ice jams), because it can just pile up thicker and heavier and it takes so much more to break it up,” Gehnert said.
She added the reports she has been getting from ice fishermen who have been out on the Yellowstone recently indicate an ice sheet averaging about 2 feet thick.
“It varies from point to point, but I talked to an ice fisherman last week and he said he’s been drilling through 20-24 inches, and another guy said he’s been drilling through up to 28 inches,” Gehnert said.
With the conditions ripening for the river ice to break out and potentially cause ice jams, Gehnert reiterated that locals with equipment, livestock, or other property they value that can be moved may want to get those things away from the river and up to higher ground as soon as possible.
State officials are also concerned about flooding not just along the river, but localized flooding from the meltwater coming off the heavy blanket of snow that has built up over much of the Yellowstone basin this winter. State Auditor Matt Rosendale repeated a call this week for Montanans living along the Yellowstone to strongly consider purchasing flood insurance if they don’t already have it, noting that it typically takes 30 days from the date of purchase for flood insurance policies to go into effect.
Besides all that, with the ice on the river visibly thinning by Tuesday afternoon, Gehnert said it’s time for ice fishermen to hang up their augers for the season and that local residents need to stay far away from the river and its banks for the time being.
“It’s not safe to be out on it at this point and we just need people to be smart about it,” she said.
Reach Jason Stuart at firstname.lastname@example.org.