WISE water remains unsettled as town revisits Aurora Water's rate structure

Castle Rock continued its commitment to Denver and Aurora, with a caveat — the town wants a second look at the way the water providers set their rates.

Castle Rock’s utilities department on Feb. 19 updated councilmembers on the Water and Supply Infrastructure and Supply Efficiency agreement for the purchase of water from Denver and Aurora. The agreement is a partnership with 10 members of the South Metro Water Supply Authority.

Castle Rock in January selected WISE as one of two solutions for its long-term water supply. WISE has been on the map since February 2008, when the WISE partnership signed an intergovernmental agreement with Denver Water and Aurora Water.

Since the town began its analysis, rate increases from Denver and Aurora prompted Castle Rock to order another rates and fees feasibility study. The rate structure in the WISE agreement is one of the greater considerations, said Heather Beasley, water resources manager.

Since 2011, the WISE delivery rate has increased about 20 cents per thousand gallons, Beasley said. Aurora also added a temporary surcharge between 17 and 51 cents per thousand gallons, Beasley reported.

“It sounds small, but we could be talking (potentially) millions in increase for our residents,” said Mayor Paul Donahue. “We are concerned about being able to control that rate.”

Castle Rock has targeted up to 1,000 acre-feet per year from WISE; one acre-foot contains almost 326,000 gallons of water.

“Enough has changed in this WISE water delivery agreement since we did the comparative analysis last year,” Beasley said. “We think it’s prudent to do another rates and fees feasibility study to be sure WISE is still one of the better sources for the town.”

Other factors impacting WISE are negotiations among Western Slope providers, who must sign off to allow Denver and Aurora to sell the water to the WISE partners; targeting the pipeline infrastructure to get the water from Aurora to the south metro service area; and meeting the terms of the U.S. Army Corps of Engineers permit amendment requirements to store the water in Rueter-Hess.

“If we can’t get that permit revised, WISE isn’t in force,” Beasley said.

The results of the new rates and fees feasibility study is expected in April, when councilmembers receive their next update on the long-term water plan.