Thursday February 8, 2024
Bureau of Reclamation —
The Bureau of Reclamation today released a draft Supplemental Environmental Impact Statement (SEIS) that analyzes varying the timing of water released from Glen Canyon Dam to disrupt the downstream establishment of nonnative fish, primarily smallmouth bass.
This document supplements the 2016 Glen Canyon Dam Long-Term Experimental and Management Plan (LTEMP) Final Environmental Impact Statement (FEIS) and Record of Decision. Glen Canyon Dam impounds Lake Powell, the largest storage unit of the Colorado River Storage Project.
The proposed updates to the 2016 LTEMP FEIS are in response to increasing numbers of warmwater predatory fish below Glen Canyon Dam, which can prey on native fish threatened under the Endangered Species Act. As Lake Powell’s elevation has declined, the epilimnion (the warmest, top-most layer of the reservoir), where these nonnative, warmwater predators reside, has become closer to the dam’s water intakes. As a result, warmwater predatory fish are more likely to pass through the dam into the Colorado River.