Corps releases final design refinements for Isabella Dam project

Published Oct. 13, 2016

SACRAMENTO, California – The U.S. Army Corps of Engineers Sacramento District released its Finding Of No Significant Impact, or FONSI, today for design refinements to the Isabella Lake Dam Safety Modification Project in Kern County.

The FONSI states that proposed refinements to the dams and spillway design would have no significant long-term effects on environmental, social or cultural resources. The determination is based on findings and analyses presented in Final Supplemental Environmental Assessment #5, which was also released today.

Design refinements in the environmental document address material disposal at Engineers Point; construction of a permanent Corps office and maintenance facility; realignment of Barlow and Ponderosa roads; realignment of the Auxiliary Dam left abutment; and installation of dam security features. All of the refinements are designed to reduce resource impact, project costs, and the likelihood and associated consequences of dam failures.

Final SEA #5 is a follow-up to the Isabella Lake DSMP environmental impact statement completed in 2012, which initially addressed the project design.

The FONSI and Final SEA are available on the project web page at

To learn more about the authorized dam safety modification project, copies of the Environmental Impact Statement and Record of Decision are also available on the project web page or by contacting the Sacramento District Public Affairs Office, 1325 J Street, Sacramento, CA 95814; Phone (916) 557-5100; email:

Completed in 1953, Isabella Lake Dam is located approximately 42 miles northeast of Bakersfield. The reservoir is impounded by two earthen dams on the Kern River and Hot Springs Valley. Today, Isabella Lake and its dams reduce flood risk for Bakersfield and the surrounding region, and is a primary water source for water users throughout Kern County. The Isabella Lake Dam Safety Modification Project will address over-topping, seismic and seepage issues identified with Isabella Lake’s Main and Auxiliary dams to reduce the likelihood of dam failure. In 2013, the Corps entered the pre-construction engineering and design phase of the project. Relocation construction work is scheduled to begin later this month. Construction of the dam modifications is scheduled to begin in 2017.

Rick Brown

Release no. 16-050