DENVER—Colorado residents are bracing for floods as record mountain snows begin to melt, but authorities say it’s too early to predict when or where rivers will overflow their banks.
Extended warm weather could melt the snow quickly and fill mountain streams with surging runoff, state climatologist Nolan Doesken said, but alternating cool and warm spells could make the runoff more gradual.
“That is the piece of the puzzle we’re still waiting on,” he said Wednesday at a meeting of the Colorado Flood Task Force.
Tom Browning, task force chairman, said he’s more concerned about flooding now than he has been all season. But he stressed that predicting floods isn’t an exact science.
Minor flooding was reported this week on the Yampa River in the Steamboat Springs area of northwest Colorado.
Mountain snow depths are averaging 247 percent of normal statewide. The snow remains deep even on south-facing slopes, which are usually the first to melt because they’re more likely to receive direct sunshine.
The amount of water in the snow is at record highs, said Mike Gillespie, supervisor of the Colorado Snow Survey for the federal Natural Resources Conservation Service.
One Snow Survey measuring site, in the Park Range northeast of Steamboat Springs, had more than 200 inches of snow containing the equivalent of 72.6 inches of water. That’s a record for any Snow Survey site in the state, according to the NRCS website. The previous record at that site was 71.1 inches of water, set in 1978.
Doesken said deep snowpack in late spring is one of the key indicators that the runoff could bring floods.
“Check. We got that one,” he said.
The forecast calls for cooler, seasonal weather over the weekend, but next week could bring warm temperatures, forecasters said.
“I’m really concerned if there’s a way to get rid of this much snow in a well-behaved way,” Doesken said.
About 200 people turned out for a meeting in LaPorte Wednesday evening to hear the Larimer County Sheriff’s Department and other agencies talk about possible flooding along the Cache la Poudre River in northern Colorado. Authorities said they couldn’t predict with any certainty what will happen because of all the variables.
Joni Suther, who lives about 150 feet from the Poudre River, said she isn’t waiting until the waters rise. She said she and her neighbors have been filling sand bags and building walls around their homes.
“Last week we used probably 26 tons (of sand) among four houses,” said Suther, adding that she expects to pile about 500 sand bags around her home.
