The forecast for the spring runoff on the Animas River does not look promising: below-average water volumes, a below-average peak flow and an early snowpack melt.
“I think, unfortunately, it’s one of those years that’s kind of a bummer,” said Ashley Nielson, a senior hydrologist with the Colorado River Basin Forecast Center. “Everything is going to be below average.”
Snowpack in the San Juan Mountains this winter hovered near historic averages, according to Snotel sites, which track snow depth.
But Snotel sites tell only part of the story.
For one, there are a limited number of sites in the basin. And this year, elevations above most Snotel sites around 11,000 feet didn’t receive as much snow as usual.
To make matters worse, drought conditions last summer and fall caused the ground to dry up significantly, so soil likely will absorb more snowmelt than normal, at the expense of rivers and streams.
As a result, the Colorado River Basin Forecast Center predicts the Animas River will receive about 70% of the water it usually does in spring, Nielson said.
The forecast center also predicts the Animas River likely will hit a peak flow of 2,300 to 2,500 cubic feet per second, though as much as 3,000 cfs is possible.
“There’s always some uncertainty in predicting peak flows, but the take-home message is it’s going to be below normal,” she said.
The Animas River’s average peak flow is about 4,700 cfs, usually in early June. Water managers are concerned that runoff this year is starting early because of high temperatures the past few weeks.
As of Friday, Snotel records show Southwest Colorado’s snowpack is melting at an accelerated rate: snowpack in the San Juans is 70% of normal historic averages for this time of year.
Jarrod Biggs, assistant utilities director for the city of Durango, said a heavy snowpack year in the winter of 2018-2019 provided good storage for the town’s reservoir, which should help water reserves during a below-normal runoff.
The city of Durango gets most of its water from the Florida River and supplements supply from the Animas River when demand increases.
“We are probably in pretty good shape,” Biggs said. “But if this dry, hot weather persists, particularly in August and September, then maybe we can start to worry.”
Water is not being pulled from the Animas River to Lake Nighthorse this year, said Russ Means, general manager of the reservoir, as crews work on the intake structure across from Santa Rita Park.
Friday, the Animas River was running at 1,700 cfs, which is 25% higher than average for this time of year, said Frank Kugel, director of the Southwestern Water Conservation District.
Over the weekend, flows were expected to increase to 40% higher than normal.
“It’s great that there’s that much water in the river, but with that much water coming off now, there will be less available later in the season,” he said. “It’s a little disconcerting for the water supply for later this summer. And I envision the boating season will be shorter than usual.”
While the Animas River’s discoloration has caught the attention of some residents in recent days, hearkening shades of the Gold King Mine spill, it does not appear contamination has occurred.
Katherine Jenkins, a spokeswoman for the Environmental Protection Agency, said everything was running as normal at the water treatment plant up Cement Creek, which treats discharges out of the Gold King Mine.
Like every spring, snowmelt brings sediment into rivers and creeks.
“Therefore, as has happened in the past, water in the creeks and river may appear to be muddy or discolored,” she said.
Jim Donovan, director of San Juan County’s Office of Emergency Management, also said conditions appear normal in Silverton. He said the source of the Animas River’s discoloration likely came from lower areas.
jromeo@durangoherald.com
