Court Allows Gross Reservoir Expansion for Denver Water

A federal appeals court has ruled in favor of the U.S. government and Denver Water, permitting the continuation of the Gross Reservoir expansion project near Denver. This decision overturns a previous ruling that had halted construction, allowing Colorado's largest water utility to potentially triple the reservoir's storage capacity. The expansion is a critical component of Denver Water's long-term strategy to ensure a reliable water supply for its growing service area, which serves over 1.5 million people in the Denver metropolitan region. The project aims to increase the reservoir's storage from approximately 42,000 acre-feet to over 120,000 acre-feet.

The ruling by the three-judge panel of the 10th U.S. Circuit Court of Appeals addresses concerns raised by environmental groups and downstream users regarding the potential impacts of diverting more water from the Colorado River system. These concerns are particularly acute given the ongoing drought conditions and declining water levels in the Colorado River, a vital water source for seven U.S. states and Mexico. Critics of the expansion argued that increasing storage at Gross Reservoir would exacerbate water scarcity issues in the basin and negatively affect ecosystems dependent on the river's flow. The court's decision, however, found that the U.S. Bureau of Reclamation, which is involved in the project, had adequately considered the environmental impacts and complied with federal law.

Denver Water has been planning the Gross Reservoir expansion for years, citing the need to secure water for future generations and to provide a more resilient water system capable of withstanding droughts and other climate-related challenges. The utility's "Water 2050" plan outlines strategies for meeting projected demand, which includes increasing storage capacity, promoting water conservation, and exploring new water sources. The Gross Reservoir expansion is a cornerstone of this plan, intended to capture more water during periods of high flow, often in the spring, for use during drier months and years. The project involves raising the dam by 30 feet and expanding the reservoir's footprint.

The legal challenge against the expansion was spearheaded by environmental organizations and local communities concerned about water rights and environmental degradation. They contended that the Bureau of Reclamation's environmental impact statement was insufficient and that the project would lead to significant harm to the environment, including impacts on endangered species and aquatic habitats. The initial ruling that halted construction was based on these environmental concerns. However, the appeals court's reversal signifies a victory for Denver Water and the federal government, clearing a significant hurdle for the project's completion. The full implications for the Colorado River Basin's water management and environmental health remain a subject of ongoing debate and scrutiny.