Western Colorado Area Office Home   |  Environmental Documents 

Reclamation proposes to operate the Aspinall Unit to avoid jeopardy to downstream endangered fish species while maintaining and continuing to meet all of the congressionally authorized purposes. Reclamation would implement the Proposed Action by modifying the operations of the Unit, to the extent possible, to help achieve river flows recommended by the Upper Colorado River Endangered Fish Recovery Program (Recovery Program). Changes in operations are based on Flow Recommendations determined by the Recovery Program.

The purpose of modifying the operations of the Aspinall Unit is to provide sufficient releases of water at times, quantities, and duration necessary to avoid jeopardy to endangered fish species and adverse modification of their designated critical habitat in the lower Gunnison River while maintaining the congressionally authorized purposes of the Aspinall Unit. The Upper Colorado River Basin at one time was inhabited by 14 native fish species, four of which are now endangered. These four fish are the Colorado pikeminnow, razorback sucker, bonytail, and humpback chub; they exist only in the Colorado River Basin. The four fish are endangered because of adverse impacts to their habitat over the last 125 years. The two types of habitat impacts that appear to have the greatest effect have been water development and introduction of non-native fish (Recovery Program 2008). Reclamation is required to comply with the Endangered Species Act (ESA) for operation of the facilities of the Colorado River Storage Project (CRSP), which includes the Aspinall Unit. Within the exercise of its discretionary authority, Reclamation must avoid jeopardizing the continued existence of listed species and destroying or adversely modifying designated critical habitat

This change in Aspinall Unit operations would assist in conserving endangered fish in the Gunnison and Colorado rivers and would maintain congressionally authorized purposes. The DEIS describes and analyzes environmental effects resulting from the proposed operational changes to the Aspinall Unit. The DEIS has been prepared according to provisions of the National Environmental Policy Act of 1969 (NEPA) and other laws and mandates.

Please submit questions or comments to: aspinalleis@uc.usbr.gov