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Last Update: 10/14/2026 at 6:33 AM EST

Gross Reservoir Expansion

Coverage from The Colorado Sun, Spencer Fane, and others

Gross Reservoir Expansion topic image

The Gross Reservoir expansion is a Denver Water project in Boulder County, Colorado, that raises Gross Dam and adds about 77,000 acre-feet of storage.

Denver Water presents the added capacity as support for water supply and drought and emergency resilience; the project also involves water from the Colorado River Basin. Its federal permits have been challenged over whether environmental review adequately considered climate-driven changes in flows, alternatives, and downstream impacts. Construction, permitting, court proceedings, and the reservoir’s eventual filling are all part of the project’s story.

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10/14/2026

The current version adds Denver Water’s claim that the expansion will improve drought and emergency resilience, and frames the ruling as relevant to judicial review of federal water-supply analyses. The underlying decision and its practical effect are unchanged.

All Articles7 articles
Interesting5 articles · CI Score 45–59
The Colorado Sun / Michael Booth
Gross Reservoir Injunction Returns To Appeals Court
Denver Water and environmental groups return to the 10th Circuit Court of Appeals on July 31 in Santa Fe to challenge permits and an injunction affecting Gross Reservoir expansion in Colorado.
5/28/2026 • Policy, Politics & Governance • General
Spencer Fane / John L. Watson
Tenth Circuit Clears Denver Water’s Gross Reservoir Expansion
The Tenth Circuit on September 15, 2026, cleared Denver Water to complete and fill Colorado's expanded Gross Reservoir after upholding Army Corps permits.
9/18/2026 • Policy, Politics & Governance • General
The Colorado Sun / Michael Booth
Appeals Court Clears Denver Water’s Gross Reservoir Expansion
The 10th U.S. Circuit Court of Appeals ruled in Colorado that Denver Water may complete and fill the Gross Dam expansion after upholding Army Corps permits.
9/15/2026 • Policy, Politics & Governance • General
Inside Climate News / Wyatt Myskow and Jake Bolster
Court Allows Colorado Dam Expansion Despite Climate Concerns
The 10th Circuit Court of Appeals ruled for the U.S. Army Corps of Engineers and Denver Water, allowing Gross Reservoir expansion near Denver to continue despite Colorado River scarcity concerns.
9/16/2026 • Policy, Politics & Governance • General
Source New Mexico
Colorado Reservoir Case Tests Climate Review Of Water Projects
The 10th U.S. Circuit Court of Appeals is considering whether the U.S. Army Corps of Engineers adequately assessed climate and water-supply risks in Denver Water's Gross Reservoir expansion near Boulder, Colorado.
8/20/2026 • Policy, Politics & Governance • General
Additional2 articles · CI Score below 45
Maven's Notebook / Wyatt Msykow and Jake Bolster
Colorado River Dam Case Tests Climate Review Requirements
In 2025, the 10th U.S. Circuit Court of Appeals heard arguments over whether the Army Corps and Denver Water adequately assessed climate risks for the Gross Reservoir expansion in Colorado.
8/15/2026 • Policy, Politics & Governance • General
Inside Climate News / Wyatt Myskow
Colorado Dam Expansion Faces Climate And Water Availability Test
The 10th U.S. Circuit Court of Appeals heard arguments in Santa Fe on whether climate change and declining Colorado River supplies require additional review of Denver Water's Gross Reservoir expansion.
8/15/2026 • Policy, Politics & Governance • General