Castle Rock plan aims to meet town’s water needs with renewable supplies by 2065

Castle Rock Water’s proposed 2026–31 strategy aims to meet all town water needs with renewable supplies by 2065, while reserving groundwater for drought and peak demand, the town’s October report says.

The proposed work would raise the Plum Creek Water Purification Facility’s treatment capacity to 12 million gallons per day, expand underground storage, connect supplies to regional reservoirs and continue conservation programs. The October report described the plan as under development and said it was expected to go to Town Council by the end of 2026.

Renewable sources accounted for 22.5% of reported water supply in October and 29.3% year to date. Separately, October demand was 274.2 million gallons, 9.2% lower than October 2025, while daily peak demand reached 12.6 million gallons, 2% above the five-year average.

The report said parts of northern Douglas County were classified as experiencing moderate, severe or extreme drought by the U.S. Drought Monitor, a regional measure. South Platte River Basin snowpack water equivalent was 35% of median, and year-to-date precipitation was 71% of median. Castle Rock’s Water Supply Index was 3.4; the report says a reading below 1.1 triggers a drought stage.

The report also said the Plum Creek facility had been offline since Sept. 30 but did not identify a cause or return-to-service date. About 53 residents attended an Oct. 8 open house; the report said attendees supported the plan’s direction while raising concerns about growth and water supplies.