Reclamation, DWR to perform exploratory work near B.F. Sisk Dam

By on March 27, 2020

The Bureau of Reclamation and the California Department of Water Resources are conducting exploratory work, including clearing, excavation and controlled blasting of rock material in the Basalt Hill area near B.F. Sisk Dam, located between Los Banos and Gilroy, between 6 a.m. to 8 p.m. during April and May.

The exploratory findings on Reclamation lands will help identify size and quality of granular material for the planned construction of a Safety of Dams Modification project.

The joint project between Reclamation and DWR will add stability berms and other physical features to the existing 3.5-mile-long earthen B.F. Sisk Dam to reduce risks associated with a large seismic event.

The public may hear the controlled blasting when it occurs, but it is not expected to impact the public or the environment. Controlled blasting is a commonly used practice at dam construction sites throughout the United States. Public roads will remain open during the controlled blasts; check recreation area updates on San Luis Reservoir and B.F. Sisk Dam websites before visiting in April.

Construction on the multi-year project is planned for summer of 2021. An environmental impact statement/environmental impact report was completed in September 2019, with the Record of Decision/Notice of Determination signed on December 3, 2019.

For questions, contact Mynul Chowdhury with Reclamation at 916-978-5335 or or Sara Paiva-Lowry with DWR at 916-653-9342 or

For project updates, visit