Corps to conduct test-blasting operations at Isabella Lake

Published Nov. 14, 2018

SACRAMENTO, Calif. – The U.S. Army Corps of Engineers Sacramento District and its contractor Flatiron/Dragados/Sukut Joint Venture will conduct test-blasting operations as part of the Isabella Dam Safety Modification Project on Thursday, November 15, starting at 12 p.m., forcing a short-term closure of Highway 155 near the main dam.

Additional test-blasting will also occur after the Thanksgiving holiday; however, a specific date and time has not yet been determined.

Production blasting is expected to begin in mid-December and will clear out rock for construction of a new emergency spillway between the main and auxiliary dams.

Construction flaggers will be present to provide traffic control during blasting operations.

Audible warning signals will alert the public of an impending blast and will signal when the operation is complete –
Five Minute Warning – a one-minute series of long horn blasts
One Minute Warning – a series of short horn blasts
All Clear – one long horn blast

Completed in 1953, Isabella Lake Dam is located approximately 40 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. Construction of the dam modifications began in 2017 with the relocation of facilities within the project footprint, and are estimated to be complete in 2022.

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

EDITOR'S NOTE:  This story has been edited to reflect changes to additional test blasting dates. Test blasting initially scheduled for November 21 has been cancelled and  test blasting scheduled for November 28 will be rescheduled.

Rick Brown

Release no. 18-033