Middle Eagle 1: Gore Creek to Avon WWTP

Current and Historical Drivers of Degradation

Although this segment is not listed as an impaired waterway by Colorado’s Water Quality Control Division, macroinvertebrate health indices in Avon hover slightly above the state of Colorado’s impairment threshold and are consistently lower than sites upstream and downstream. Indices of sensitive taxa presence are the lowest of anywhere on the mainstem Eagle River, indicating degraded water quality conditions. Impacted bug life scores are likely driven by urban runoff and degraded riparian buffer conditions in the vicinity of Avon.

The frequency of peak flows equivalent to the natural 1-in-4 year flood have declined nearly 60% compared to the historic condition due to upstream water use and management. Peak flows during dry years have declined 21% and total annual volumes have declined 22% when compared to natural historic conditions.

Report Card