Regional water supply projects are being developed south-of-Delta and on the west side of the San Joaquin Valley which would greatly benefit local farms, communities and wildlife.
Two of these projects that will greatly enhance the ability to store water in wet years for use in low allocation water supply years are raising the B.F Sisk Dam at the San Luis Reservoir and the Del Puerto Canyon Reservoir located just northwest of Patterson.
B.F Sisk Dam
Some of our local citizens are old enough to remember the time when President John F. Kennedy flew in over Los Banos in Marine 1 and landed in a cloud of dust near what we now call Kennedy Hill.
On Aug. 18, 1962, 60 years ago, he came as the leader of this nation to appropriately lend significance to the groundbreaking ceremonies of the San Luis Dam Project near Los Banos.
Standing on what is now called Kennedy Hill, surrounded by national, state and local dignitaries, and local citizens, he gave a visionary speech about the possibilities of water development brought about by cooperation and vision. California was still at that time in the forefront of the water supply project development that made us the economic and agricultural powerhouse we are today.
The B.F. Sisk Dam and San Luis Reservoir are an integral part of the Central Valley Project/California State Water Project (CVP/SWP) system. The dam and reservoir are located on San Luis Creek approximately 12 miles west of Los Banos, California. The dam is an off-stream water storage facility.
The water stored in the reservoir is managed for federal (45%) and state (55%) uses as part of the CVP and SWP, respectively. Over 25 million Californians, two million acres of farmland and 200,000 acres of managed wetlands in the Pacific Flyway receive a portion of their water supply from the projects.
Safety of Dams (SOD) Modification Project – 12 Foot Dam Raise
A series of studies and analyses culminating in the seismic risk analysis that was completed in 2006 determined that action needs to be taken to reduce risk to the downstream public.
Consequently, the U.S. Bureau of Reclamation, in collaboration with the California Department of Water Resources (DWR), is proceeding with the B.F. Sisk Dam Safety of Dams (SOD) Modification Project.
The SOD Modification Project raises the dam crest by 12 feet to provide seismic stability for the embankment during a large earthquake. This raise, however, does not provide for any additional water supply storage. Pre-construction work has already started on the SOD Modification Project with work on this phase scheduled to be completed by 2026.
Additional Water Storage Benefits – An Additional 10 Foot Dam Raise
In coordination with Reclamation, the locally based San Luis & Delta-Mendota Water Authority (SLDMWA) is pursuing a project to further raise the dam to provide additional water supply storage benefits.
The increased storage capacity would be achieved by an additional 10-foot raise of the B.F. Sisk Dam embankment across the entire dam crest above the level proposed for dam safety purposes and would add approximately 130,000 acre- feet of water storage to San Luis Reservoir.
SLDMWA, in coordination with U.S. Bureau of Reclamation, is completing environmental and permitting studies for the increased storage project and is anticipating a federal cost-share in accordance with the Reclamation SOD Act and the Water Infrastructure Improvements for the Nation (WIIN) Act.
In addition to increasing storage capacity of San Luis Reservoir, the project also includes modifications to State Route (SR) 152 to protect the roadway against higher storage levels and to increase seismic stability of the embankment.
This phase of the project, if approved, would be scheduled to be ready for construction in 2026 to build off of the SOD Modification Project and be completed by the year 2030.
Del Puerto Canyon Reservoir Project
In the next article in this series, we will describe the Del Puerto Canyon Reservoir Project which is currently being developed by the Exchange Contractors in partnership with Del Puerto Water District.
The local public water agencies, including the members of the SL&DMWA and the Exchange Contractors are committed to being good stewards of the water resources they receive and continue to invest in sustainable water systems that prepare them for the future.