Editor’s note: This story was published in collaboration with the Aspen Daily News.

A 15-day trial has been set for Oct. 28 to decide if the city of Aspen has abandoned its water rights to produce hydropower on lower Castle Creek.

The plaintiffs are five owners of land and water rights on either Castle or Maroon creeks: Bill Koch — through four corporate entities he controls — Kit Goldsbury, Dick Butera, Bruce Carlson and Maureen Hirsch.

All of the plaintiffs have either spoken out against a new hydro plant that had been proposed by the city or publicly aligned themselves with an opposition group led by Hirsch called Saving Our Streams.

The suit was filed in September 2011 and the group of plaintiffs was winnowed after the city successfully argued that only those who own water rights had standing in the case, which drew an amicus brief opposing the city’s view from Western Resource Advocates.

The city owns water rights to divert 65 cubic feet per second (cfs) of water from Maroon Creek and 160 cfs from Castle Creek for a number of decreed uses, including municipal, irrigation and hydropower. The city’s senior rights on Castle Creek date to 1885 and 1889, and on Maroon Creek to 1892.

The plaintiffs hold junior water rights either above or below the city’s diversion points and say their water rights will be diminished if the city begins diverting 52 cfs of its water from the two creeks to make hydropower.

But the plaintiffs stress that they don’t have to prove injury in the case, they only have to hold Aspen to a strict standard of proof of abandonment.

“Use it or lose it” is a maxim of Colorado water law and the city concedes it has not diverted water to make hydropower at a plant under the Castle Creek bridge for over 50 years.

But in an abandonment case, “intent to abandon” also must be proved, and the city firmly denies it intended to abandon its rights.

The plaintiffs say they are not trying to prove the abandonment of other aspects of the city’s water rights, just the right to use its water for hydro on lower Castle Creek.

In 2007, Aspen voters approved building a new hydropower plant in the same location on the banks of Castle Creek where one operated from 1893 to 1958. But in November 2012, Aspenites voted to suspend work on the project, which is still under review by the Federal Energy Regulatory Commission.

Post-election, city officials asked for suggestions on how it should best meet its renewable energy goals, but Aspen City Council has not otherwise taken action on the proposed plant.

Judge James Boyd of the 9th Judicial District is presiding over the case in Division 5 water court in Glenwood Springs, where the trial is slated to be held.

Paul Noto of Patrick, Miller and Kropf in Aspen is attorney for the plaintiffs. Cynthia Covell and Andrea Benson of Alperstein & Covell in Denver are representing the city.

The parties in the case must complete one session of mediation or other methods of dispute resolution by July.

Editor’s note: See also “A look at who is suing Aspen over water rights for hydro,” by Aspen Journalism.

Brent Gardner-Smith, the founder of Aspen Journalism, and who served as AJ’s executive director until August 2021 and as editor from 2011-2020, is the news director at Aspen Public Radio. He's also been...