Gore Creek: Vail WWTP to Eagle River

Current and Historical Drivers of Degradation

The section of Gore Creek below Vail is included on Colorado’s 303(d) list of impaired waterways for impacts to aquatic life. Water quality degradation manifests in low aquatic macroinvertebrate heath index scores. Expected sources of degradation include urban stormwater runoff, riparian degradation, pesticide/herbicide application, and transportation infrastructure runoff. This section of Gore Creek is also impacted by discharges from the Vail Wastewater Treatment Plant (WWTP). Somewhat elevated nutrient concentrations are evident in recent water quality datasets.

Water storage and operations of Black Lakes and water withdrawals for municipal supply produce only modest impacts to the flow regime in Gore Creek. Winter water withdrawals for snowmaking can impact streamflows in a relatively larger manner, but are generally offset by discharges from the WWTP and augmentation releases from Black Lakes. Peak flows during typical and dry years have declined more than 20% since pre-development periods.

A statistical trends analysis shows significant declines in late summer streamflows between 1996-2020.

Report Card