Denver Water is planning a major expansion of the reservoir that will increase height of the Gross Reservoir Dam outside Boulder by 131 feet and water storage by 77,000 acre-feet. Local residents and environmental groups are fighting against the expansion. (Chris Schneider, Special to The Colorado Sun)

BOULDER — Boulder County has suspended consideration of a permit needed for a long-sought reservoir expansion by Denver Water until a federal court hears a lawsuit filed by the utility that alleges the county is stalling on the permit and jeopardizing the project.

The county on Tuesday said it had agreed to a Denver Water request to put the process on hold pending the outcome of the suit, which Denver Water filed in U.S. District Court on July 14. It canceled public hearings on the project set for August and September.

Denver Water contends it has made good-faith efforts over several years on a local-use land review needed to begin work on Gross Reservoir. It alleges the county has used the process to delay the review, jeopardizing federal and other deadlines for the project.

In June, county planning and permitting staff determined that Denver Water hadn’t provided satisfactory answers to requests for information on the project.

The Gross Reservoir Expansion Project would be the largest construction project in the history of Boulder County. It would raise the 340-foot (104-meter) Gross Dam by an additional 131 feet (40 meters), increasing reservoir capacity by 77,000 acre-feet.

Environmentalists and many local residents argue it will cause serious impacts to the environment.

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