The East Boulder Climate Group, headquartered at the Frasier Meadows Retirement Community, has focused on the crucial relationship between water and climate change. We are particularly concerned about the Gross Reservoir Dam issue. This issue is not merely of concern to the communities of Boulder and Denver; it serves as an indicator of whether our country has the foresight and determination to deal effectively with the climate change crisis. Halting further construction of and prohibiting the enlargement of Gross Reservoir, as a recent decision by the U.S. District Court of Colorado requires, is both troublesome and expensive. But it is an essential part of the imperative effort to address climate change, an effort that will often be both troublesome and expensive.

The East Boulder Climate Group would like to thank three courageous agents in connection with the Gross Reservoir Dam issue — the six environmental groups that brought legal action against the Army Corps of Engineers that authorized expansion of the Gross Reservoir Dam and Reservoir; U.S. District Judge Christine M. Arguello for her bold, thoughtful, and comprehensive legal decision that prohibits enlargement of Gross Reservoir and prevents further construction of the Gross Reservoir Dam until it is established how the existing structure can be made safe; and Boulder County Commissioner Claire Levy whose concise summary of Judge Arguello’s decision spread awareness of this issue far more broadly.

The Army Corps of Engineers’ conduct regarding the Gross Reservoir Dam was, in our opinion, grossly negligent. Its dredge-and-fill permit appears to have violated the Clean Water Act, the Administrative Procedure Act and the National Environmental Policy Act. The Corps apparently failed to consider many plausible alternatives for meeting Denver’s water needs. Consequently, it failed to establish that the expansion of the Gross Reservoir Dam and Reservoir was the “Least Environmentally Damaging Practicable Alternative” as required by environmental law.

There are alternative ways of meeting Denver’s water needs, including reducing water demand by reforming outdoor water use by things like improved irrigation practices and replacing nonfunctional turf grass; reusing highly treated wastewater which could be returned directly to the drinking water system; developing smaller, less environmentally damaging storage projects or a distributed network of storage, pipelines, and aquifer recharge facilities. Denver could work with agricultural water users on voluntary, compensated agreements to temporarily transfer water during droughts or high-demand periods.

It is important to understand the environmental damage that the expansion of the Gross Dam and Reservoir could cause. It would divert additional water from the headwaters of the Colorado River, particularly from the Fraser River, which is already heavily used and considered one of the most endangered rivers in the United States. These diversions would exacerbate the decline of Western Slope waterways, harming aquatic habitats and reducing vital stream flows. It would require the removal of approximately 500,000 to 650,000 trees from about 460 acres of forest, including at least one acre of old-growth ponderosa pine forest. Such deforestation destroys wildlife habitat, disrupts local ecosystems and generates about 50,000 tons of forest waste.

Removal of forests would reduce carbon sequestration capacity. Increased evaporation from a larger reservoir could further stress water supplies as regional temperatures rise. Climate change is expected to decrease stream flows, making the long-term viability of the project questionable. Climate models predict reduced precipitation and increased evaporation that could leave the expanded reservoir without enough water to justify its construction. By 2050, scientists warn there may not be enough water to fill even the existing reservoir.

The Denver Water Plan entails increasing the height of Gross Dam from the current 340 feet to 471 feet (a 39% increase) and expanding the storage capacity of Gross Reservoir from 42,000 acre feet to 119,000 acre feet (a 283% expansion). For the reasons detailed above (by no means a complete list), the East Boulder Climate Group (as well as most Colorado environmental organizations) strenuously opposes these changes. We maintain that Gross Dam should remain as it is. The work that has already been done refurbishes the dam and reservoir and is certainly not wasted. We hope our court system has the wisdom to endorse this environmentally responsible proposal.

Tom Mayer and Bev Postmus are writing on behalf of the East Boulder Climate Group.