Lake Nighthorse is sitting pretty in terms of the amount of water stored in the reservoir just outside Durango, according to water managers.
Despite the extreme drought that plagued Southwest Colorado from fall 2017 to fall 2018, Lake Nighthorse never had a serious depletion of water storage and, in all likelihood, was one of the most full reservoirs in Colorado.
According to Bureau of Reclamation data, the 120,000 acre-foot reservoir is at nearly 95% capacity. For reference, other area reservoirs, such as Vallecito and Lemon, are at 26% and 20% capacity, respectively.
Russ Howard, manager of the Animas-La Plata Operations and Maintenance Association, which manages Lake Nighthorse, said snowmelt from Basin Creek, the drainage where the reservoir sits, replenished the lake with nearly 2,000 acre-feet of water.
“Now, we need less than a foot of water to top off the reservoir,” he said.
As a result, Howard said water managers don’t need to pump as much water out of the Animas River to refill the reservoir.
“We’re not going to pump near as long as we normally do,” he said. “Maybe only two or three weeks.”
But pumping is not likely to happen anytime soon, as water quality is currently compromised by runoff from the 416 Fire burn scar into Hermosa Creek, a tributary of the Animas River.
“Charcoal. Ash. You see it all right now, and it’s not pretty,” Howard said. “We take the water quality of Lake Nighthorse very seriously … so we’ll probably wait until later in the season to actually pump to allow for water quality to improve.”
Howard said it’s important to run the pumping plant every year, just to make sure the equipment is operating as expected. He said he’s still working out a contract with Western Area Power Administration for the cost of pumping this year.
Lake Nighthorse loses about 2,700 acre-feet to evaporation every year, Howard said. But because of the runoff from Basin Creek, which rarely contributes a significant amount of water to the reservoir, that amount has already almost been made up.
“This is a good year,” Howard said.