Trenching, boring to start at Isabella Lake in October for Corps dam study

Published Sept. 19, 2011

SACRAMENTO, Calif. – The U.S. Army Corps of Engineers Sacramento District is set to begin geotechnical studies at Isabella Lake in early-to-mid-October as part of the Isabella Lake Dam Safety Modification Project. The study results will help determine whether soil and rock near the lake is suitable for use in proposed safety upgrades to Isabella Lake main and auxiliary dams.

From October 2011 through early March 2012, the Corps, in cooperation with the U.S. Forest Service Sequoia National Forest, will perform trenching and boring work at five locations around Isabella Lake. Study areas include the vicinity of the USFS Lake Isabella Office; the right abutment of the auxiliary dam; the Auxiliary Dam Recreation Area; the Southlake area west of the South Fork Wildlife Area; and Hanning Flat Recreation Area. Although these areas will remain open for public use during geotechnical work, certain local restrictions may apply. Visitors are encouraged to contact the USFS Lake Isabella Office at 760-379-5646 for the most current local restrictions before planning a visit to Isabella Lake.
Compliance with all applicable federal, state and local environmental laws and regulations is required for the work proposed. The studies will not involve in-water work. All work will take place a minimum of 50 meters away from any known sensitive habitats or cultural sites. An archaeological monitor will also be present during trenching work to minimize potential effects to cultural sites. Once the geotechnical studies are complete, all study sites will be restored as nearly as practical to their present conditions.

Members of the public who wish to make a comment or would like additional information are encouraged to visit the U.S. Army Corps of Engineers’ Isabella Lake website:

Comments may also be mailed to:
U.S. Army Corps of Engineers Sacramento District
Attn: Mr. Mitch Stewart, Environmental Resources Branch
1325 J Street
 Sacramento, CA 95814

Chris Gray

Release no. 11-020