Corps finds no evidence of damage at Isabella Lake Dam following nearby earthquake

Published July 25, 2013

SACRAMENTO, Calif. – Inspections of Isabella Lake Dam have found no evidence of damage or increased likelihood of dam failure following a 4.3-magnitude earthquake yesterday.

The earthquake hit at 9:46 a.m. July 24, approximately 20 miles southeast of the dam, according to the U.S. Geological Survey.  

Instrumentation used to monitor the dam recorded the quake, prompting a follow-up inspection by U.S. Army Corps of Engineers Sacramento District staff, including southern operations area manager Calvin Foster.

“We performed an inspection of the dam, tower, outflow areas and other embankments for changes in appearance or signs of damage,” Foster said. “We found no evidence of change or damage following yesterday’s event.”

The Corps is in the process of designing dam safety modification features for the main and auxiliary dams to address overtopping, seismic and seepage issues. The project, which will include a 16-foot raise to both dams to reduce the likelihood of dam failure, is scheduled to begin construction on the dam safety features in 2017.

"This event is a powerful reminder that Isabella Lake is in an active seismic region, and that's a significant part of the reason we need to rehabilitate the dam," said Rick Poeppelman, chief of the Sacramento District’s engineering division.   

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 help reduce flood risk for Bakersfield and the surrounding region, and are a significant water source for water users throughout Kern County.

Tyler Stalker

Release no. 13-051