Lake Isabella is located 40 miles northeast of Bakersfield, Kern County, California, and consists of an earthfill main dam and auxiliary dam across the Kern River and Hot Springs Valley, respectively. The dam was authorized under the Flood Control Act of 1944 and construction was completed in 1953.
The reservoir provides flood-risk management, irrigation and recreational benefits. With more than 300,000 people living and working below the dams, primarily in the town of Lake Isabella and the city of Bakersfield, the U.S. Army Corps of Engineers began a dam safety modification study in 2006 to address seismic, hydrologic (potential over-topping during an extreme flood event) and seepage issues at the dams.
Following the signing of the Record of Decision in December 2012, USACE entered the Pre-Construction Engineering and Design phase of the project, and from 2013 to 2016, focused on design improvements to the existing dams and the relocation of U.S. Forest Service buildings located in the excavation footprint. Construction of the USFS warehouse/administrative buildings in Kernville and the USFS fire station in Lake Isabella were completed in 2017.
In September 2017, USACE awarded a $204 million contract to Flatiron/Dragados/Sukut Joint Venture of Benicia, California, to construct the Phase II dams and spillways modifications. Phase II was substantially completed in 2022.
Phase III construction is currently underway. It includes the construction of a new Isabella Lake Visitor Center operated by the U.S. Forest Service, as well as dam operations support facilities.
To date, the IDSMP project team has logged over 2.6 million exposure hours with no significant accidents or injuries—a massive achievement that speaks to our district's sustained culture of safety.