Publications Home || Browse by topic || Browse by program || Ecology website

Publication Summary

Our Ecology website has changed, which can cause broken links.
To report these, please contact us with the publication and broken link.


Eightmile Dam Rebuild and Restoration EIS

Publication number Date Published
24-12-004June 2024
VIEW NOW Eightmile Dam Rebuild and Restoration EIS (Number of pages: 476) (Publication Size: 63074KB)
Note: Volume 1 - EIS and Appendices A-E

Acrobat PDF format (Number of pages: 428) (Publication Size: 35MB)
Note: Volume 2 - Response to Comments (Appendix F)

Volume 2 - Response to Comments (Appendix F)
(427 pages) (34MB)

Trouble viewing? Try these free options.
Author(s) Office of Columbia River
Description Final Environmental Impact Statement (FEIS) for the rebuild and restoration of Eightmile Dam in the Alpine Lakes Wilderness within the Icicle Creek Subbasin of the Wenatchee Basin.

The publication is broken down into two volumes: Volume 1 consists of the FEIS and Appendices A-E and Volume 2 is composed of Appendix F, responses to comments recieved during the Draft EIS public comment period.

Following the 2017 Jack Creek Fire, Ecology’s Dam Safety Office (DSO) determined the dam was in an unsatisfactory condition, with an estimated 150 downstream residences at risk if the existing dam were to fail, resulting in a High Hazard classification. This hazard classification means that dam failure would threaten human lives and/or cause substantial economic or environmental damage. Because of these concerns, Icicle-Peshastin Irrigation District (IPID) and Chelan County declared an emergency at Eightmile Dam on March 13, 2018. The dam was repaired in 2018 to temporarily increase safety by widening and hardening the spillway and by replacing a segment of the low-level outlet pipe that had collapsed. The infrastructure does not currently meet DSO’s requirements for dam safety or IPID’s water supply needs. As a result of these ongoing safety concerns, DSO is requiring that the dam’s outlet gate be kept open to reduce the volume of water stored and thus reduce risk of failure during the winter and early spring until permanent repairs can be made to the dam.

The FEIS was conducted for the rebuild and restoration required to permanently fix Eightmile Dam. The EIS examines significant adverse environmental impacts of three alternatives for rebuilding the dam, as well as the impacts of operating the current dam with no changes. IPID, in coordination with Ecology, has selected Alternative 2 as the preferred alternative for reconstructing the dam. This alternative includes a wide spillway without gates. It will restore the storage capacity of the la
NOTES Volume 1 - EIS and Appendices A-E; Volume 2 - Appendix F: Response to Comments
The mission of the Department of Ecology is to protect, preserve, and enhance Washington’s environment. To help us meet that goal, please consider the environment before you print or request a copy.

ADA Accessibility
The Department of Ecology is committed to providing people with disabilities access to information and services by meeting or exceeding the requirements of the Americans with Disabilities Act (ADA), Section 504 and 508 of the Rehabilitation Act, and Washington State Policy #188.
Visit Ecology’s website for more information.
Contact Melissa Downes at 509-454-4259 or
Keywords environmental impacts, water storage, water supply, SEPA, environmental impact statement, dam safety, SEPA EIS
WEB PAGE Eightmile Dam Rebuild and Restoration
WATERSHED Water Resource Inventory Area 45 Wenatchee

Eightmile Dam Rebuild and Restoration EIS Executive Summary