Aurora staff warn Shoshoni power‑plant change case could expand senior water right; city to oppose expansion

City water staff delivered a technical briefing on May 20 about a water‑rights court case involving the Shoshoni hydropower plant on the Colorado River and reviewed implications for Aurora’s supplies.

Staff explained the River District and Xcel Energy have filed a joint change application with the Colorado Water Conservation Board seeking to add an instream‑flow right for the Shoshoni plant while preserving the historic senior date. The city’s presentation warned that if the final decree effectively expands the quantified water use of the power‑plant right it could injure other water users, and Aurora intends to press for a decree consistent with Colorado water law.

“A key concern is that the decree correctly quantify how many days they called, how much water that power plant used under the right so they can't expand it,” the staff presenter said, stressing the legal limits on preserving senior priority without expanding use. Staff described prior related litigation (Busk‑Ivanhoe settlement) and said Aurora and peer cities (Denver, Colorado Springs, Northern Water and the Bureau of Reclamation among others) have similar positions: supportive of an instream‑flow outcome but opposed to any expansion that would harm municipal rights.

Staff noted about 60 parties had filed oppositions or entered the case as interested parties; many western‑slope users favor a stronger instream‑flow right while several front‑range cities worry about potential unilateral expansion. The city said the case will likely proceed with expert testimony and may take two to three years, with mediation likely to be used.

Council members asked clarifying questions; staff emphasized that nothing in Aurora’s water deliveries changes while the case proceeds and that the city will monitor and participate in hearings and settlement discussions.

Next steps: staff will keep council updated as the case progresses and will provide deeper briefings on request.