Get ready for some high flows, and potential flooding, on the streams and rivers around Southwest Colorado as temperatures heat up.
After one of the largest snowpacks in recent history this winter, spring runoff and river levels, so far, have been tempered by cool temperatures during most of the month of May.
“We couldn’t have ordered better weather,” said Butch Knowlton, director of La Plata County’s Office of Emergency Management, referring to May.
But all that changed in the past couple of days as higher temperatures hit Southwest Colorado, causing rivers and streams to surge.
The Animas River, for instance, was at about 1,500 cubic feet per second Saturday. On Tuesday, the river was running at more than 5,000 cfs and is expected to keep rising.
By the end of the week, the Colorado River Basin Forecast Prediction Center is calling for the Animas to hit nearly 7,000 cfs. (The Animas River usually hits a peak flow of about 4,700 cfs in early June at the height of spring runoff.)
Predicting river flows is a finicky art, said Greg Smith, a hydrologist with the Colorado River Basin Forecast Center, with cloud cover, nuances in temperatures and incoming storms influencing snowmelt.
“But if this pans the way it is, we could see the seasonal peak this weekend or early next week,” Smith said. “And the Animas looks like it will end up peaking higher than we initially thought.”
If the Animas does reach 7,000 cfs, it would mark the largest peak since 2005 in the April-to-July snowmelt window, when the river hit 8,070 cfs on May 26. The last big water year was in 2015 when the Animas peaked at 6,210 cfs on June 12.
Matthew Aleska, a meteorologist for the National Weather Service in Grand Junction, said there might be a slight break in the hot conditions Wednesday, as a storm system enters the region that is expected to bring some rain and cooler temperatures.
But for the most part, the warm weather has arrived, he said. And that means snowpack in the San Juan Mountains – which is at 1,168% of normal, historic averages for this time of year – will soon melt.
“It’s starting to fully come off,” Aleska said. “It’s something we’re going to keep a close eye on.”
Indeed, Knowlton and his staff were reviewing river flow and weather predictions Monday morning in anticipation of potential flooding.
“It’s coming,” he said. “That’s the simplest thing we can say now that we have warmer temperatures.”
The Animas River at 7,000 cfs starts to spill out on the low-lying areas and fields in the lower Animas Valley north of Durango, Knowlton said. At 8,000 cfs, areas around Trimble Lane start to flood.
The water flow for the Animas River to be considered in a flood stage is about 10,500 cfs, Knowlton said. While the river may not hit that mark this year, there is a wild-card type scenario that has emergency managers concerned.
Because there haven’t been high water flows in recent years, Knowlton said there’s a risk that trees and other debris are in river channels. If enough water comes down, it could either spill into adjacent properties or dam and eventually release a large amount of water and debris.
Landowners along Junction, Lightner and Vallecito creeks should also be on high alert.
“We can’t be everywhere at once, so private property owners need to be watching,” Knowlton said.
Boaters and kayakers, too, should be aware of high water conditions, Knowlton said.
“One has to sit down and question their physical ability, knowledge of rafting and kayaking, and whether or not they should be in this type of water,” he said. “It’s a personal judgment call, but sometimes people are just not prepared to recreate in this volume of water. We’re hoping those people will stay on the bank and watch.”