Denver Water moves supply out of Antero Reservoir

Denver Water began moving water out of Antero Reservoir on May 14 as the utility responded to drought and unusually weak runoff in Colorado, according to the utility and local reports. The water is being sent downstream to Cheesman Reservoir, a deeper facility that loses less water to evaporation than Antero, which sits in Park County. Denver Water said the move is part of its drought response and is intended to preserve supplies heading into summer. The utility had flagged the plan in April and said Antero would close to recreation as the transfer began. ### Why is Denver Water moving water out of Antero now? April 20 was the date Denver Water first said it would begin moving water from Antero Reservoir to Cheesman Reservoir “in the coming weeks” as part of its drought response. The utility said Antero has the highest evaporation-to-storage ratio of any reservoir in its system, making it a target for water-saving operations during dry years. Denver Water said the same measure was last used in 2002, while a planned drought-response drawdown in 2013 was avoided after late snowstorms. (kdvr.com) May 14 was the date local television reports said the transfer was underway. Denver Water told KDVR that it was moving water across reservoirs to manage limited storage and maintain reliability during what the station described as unprecedented drought conditions. ### How much water could Denver Water save by shifting it to Cheesman? (denverwater.org) About 5,000 acre-feet is the amount Denver Water said it could keep from evaporating by moving water out of Antero and into Cheesman. The utility said that equals about 25% of Antero Reservoir’s storage capacity. Denver Water also said one acre-foot is roughly enough water for three to four single-family households for a year. (kdvr.com) Antero Reservoir’s shape is central to the decision. Denver Water said the reservoir is shallow and has a broad surface area, which increases evaporative loss, while Cheesman is deeper and more efficient for storage during drought. Denver Water described its collection system as designed to move water from Antero to more efficient reservoirs when dry conditions warrant it. (denverwater.org) ### What does the snowpack picture look like this year? April 1 is the benchmark date Colorado water managers often use to assess peak snowpack, and Denver-area reporting said some watersheds were at just 26% of normal around that point this year. Denver Water separately reported in late April that snowpack in the Colorado River Basin portion of its collection system was 18% of normal and the South Platte portion was 2% of normal, figures described in secondary coverage as the worst and second-worst on record for those parts of its system. (denverwater.org) May 15 data on Colorado snowpack remained available through federal and weather-service tracking pages that compile NRCS SNOTEL information. Those pages show statewide and basin-level snow water equivalent data used by utilities and forecasters to monitor runoff conditions. ### What changes on the ground at Antero Reservoir? May 13 was the last day of recreation access at Antero Reservoir for 2026, according to Denver Water’s recreation page. (kdvr.com) The utility said Colorado Parks and Wildlife approved a fish salvage at the reservoir effective immediately ahead of the closure. Denver7 reported on May 15 that Denver Water had closed Antero Reservoir to the public and was draining it as part of the drought response. (weather.gov) The Denver Gazette reported the reservoir was expected to be emptied within about six weeks, citing Denver Water. ### Has Denver Water taken broader drought steps this spring? (denverwater.org) April 8 was the date the Denver Board of Water Commissioners declared Stage 1 drought, imposed mandatory watering restrictions and approved temporary drought pricing, according to Denver Water’s reservoir operations page. The utility said customers should keep automatic irrigation systems off until mid- to late May. (denver7.com) Denver Water’s next public updates are likely to appear on its reservoir operations and drought-response pages, where it posts storage conditions and operating changes. As of May 15, the Antero recreation page said the reservoir would remain closed for drought response in 2026. (denverwater.org)