Corps drilling along Highway 155 for Isabella Lake dam safety project

Published Oct. 29, 2015

SACRAMENTO, Calif. - The U.S. Army Corps of Engineers Sacramento District is performing drilling operations along the northbound lane of Highway 155 in Lake Isabella, California, as part of the Isabella Lake Dam Safety Modification Project.

Traffic control measures are in place for traffic to travel through the construction zone along the southbound lane, but the roadway will remain open to traffic in both directions. Drilling will occur during daylight hours, and is expected to be complete by Nov. 6.

Geologic data from three borings will help provide pertinent information for design of a floodwall to be constructed adjacent to the roadway as part of the Corps’ project, which will raise both the main and auxiliary dams and their abutments on each end up to 16 feet.  

The Isabella Lake dam safety project is currently in the design phase, and the team is continuing to research and refine designs to allow for minimal disruption and impact when the project begins construction in 2017.

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 overtopping, 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.

 For more information on the Lake Isabella Dam Safety Modification Project, visit

Tyler Stalker

Release no. 15-050