A forecasted winter La Niña, lingering drought conditions and dwindling reservoirs are causing water managers to worry.
By Cassie Sherwood, The Water Desk
Heavy autumn rains brought relief to drought-plagued portions of the Southwest, but across the Colorado River basin ongoing water supply concerns still linger amid tense policy negotiations and near record-low reservoir storage.
Even after accounting for the heavy rain, 57% of the Colorado River watershed remains in severe drought, according to the U.S. Drought Monitor. More than 11% of the basin is in extreme drought.
A less than average upcoming snow season combined with a dry spring or early summer in 2026 could create conditions for another low runoff year. The Colorado River’s headwaters saw a weak snowpack last winter, which contributed to one of the worst spring runoff seasons on record in 2025. Drought conditions spread and worsened into summer throughout the southern Rocky Mountains.
Peter Goble, Colorado’s assistant state climatologist, explained that the recent rainfall “certainly recharged soils,” in some watersheds.
Streamflow in the Animas River and Rio Grande increased significantly following the October rains and flooding. Rain in southwest Colorado, particularly around Pagosa Springs, brought flooding that damaged homes and downtown businesses. Rain gauges near the San Juan Mountains recorded 7 to 10 inches of precipitation from October 9-15.
“We would love to see this rain come over a more steady incremental period,” Goble said. “But oftentimes it is these flooding events that kind of put the kibosh on a drought more locally.”
The flooding erased drought designations on the Drought Monitor map in those localized areas, but basinwide drought conditions tell a different story. Dry soils, depleted reservoirs and winter weather forecasts continue to cause water managers to worry.
Even with the recent rain, soils in many parts of the Colorado River basin remain dry. Soil absorbs moisture almost like a sponge. When the soil moisture is low, spring runoff soaks into the soil, saturating the ground first. Soils that are more saturated lead to more water filtering into streams and reservoirs when runoff occurs, making the process more efficient.
“We’re still going to need a good snowpack in order to be set up nicely, but this (rain) improves our outlook for the efficiency of that snowpack,” Goble said.
Federal forecasts show the possibility of a mild La Niña through February. The climate pattern occurs when Pacific Ocean waters cool down and alter global weather conditions. La Niña patterns often impact the amount of snowpack accumulation in the coming year. The southern part of Colorado is often drier in a La Niña year while northern areas, around Steamboat Springs, typically see snowier conditions.
The stakes for an above average runoff next year are high. The two biggest reservoirs in the country, Lake Powell and Lake Mead have steadily declined over the last 25 years. Powell is currently at 29% of its capacity and Lake Mead is at 32%. A lessened runoff could push them dangerously low.
While the rain slightly alleviates local drought, it’s “only a drop in the bucket when it comes to refilling Lake Powell and Lake Mead,” Goble said. “We’re still going to see those regional water shortages persist.”
If water levels continue to decline in these larger reservoirs, the dams’ infrastructure is threatened and the hydropower turbines can’t be used. Lake Powell, for example, has different outlets installed so water can be released in low conditions, however they are not designed to be the main outlet source. New federal projections show it’s possible Powell’s levels could drop low enough to cease hydropower production as early as October 2026, if conditions remain dry.
“They could reach levels they have never reached before and potentially reach catastrophic levels,” said John Berggren, regional policy manager for Western Resource Advocates.
In response to extremely low water conditions, it’s possible water from upstream reservoirs in Colorado, Wyoming and New Mexico could be released to support Powell’s hydropower turbines.
“We are seeing a new normal because of climate change, because of aridification,” Eric Kuhn said, former general manager of the Colorado River District, on the state’s Western Slope. In 2022, the basin saw similar drought conditions.
“We are back where we were just a few years later,” Kuhn said. “The system is slipping away.”
The basin states are also engaged in negotiations for new operating guidelines for the Colorado River, set to be in place by 2027. Given the ongoing drought conditions, water experts say the two reservoirs cannot wait for new guidelines.
“Don’t forget the short term problem while you are focused on a long-term agreement,” Kuhn said. A recent research paper, co-authored by Kuhn, highlights the need for urgent consumptive cuts basinwide. “We have got to figure out what’s going to happen next year if next year happens to be dry.”
This story is produced and distributed by The Water Desk at the University of Colorado Boulder’s Center for Environmental Journalism.
