Bethany Dams Improvement Project

Note: Bethany Reservoir and recreation area is open. A one-mile section of the trail along the east side of the reservoir remains closed to allow for the Dams Improvement Project.

The Bethany Dams Improvement Project that began in spring of 2021, has completed repairs and improvements  to the Bethany Forebay Dam and four saddle dams in Alameda County. The 110-foot high earthen embankment Bethany Forebay Dam and four saddle dams were completed from 1961 to 1967 and impounds Bethany Reservoir.

The California Department of Water Resources (DWR) routinely conducts inspections and reviews Bethany Dams and facilities to ensure they remain safe and are performing as intended. Inspections by DWR and independent consultants deem Bethany Dams and Reservoir safe for continued use and are being operated and maintained properly. To ensure the continued safe operation of Bethany Dams and Reservoir, dam safety inspections identified the following plans to be developed and implemented:

• a comprehensive plan to repair rodent burrow holes and repair erosion gullies, and
• a long-term plan to protect the embankments from future rodent habitation.

Located 10 miles northwest of Tracy, Bethany Reservoir serves several purposes, such as a forebay for the South Bay Pumping Plant (the start of the South Bay Aqueduct of the State Water Project), afterbay for Banks Pumping Plant, conveyance facility for the California Aqueduct, and recreational facility that includes picnicking, boating, biking, and hiking.

The Project

DWR completed the following maintenance activities as part of the Bethany Dams and Reservoir Improvement Project:

• Restoration measures – excavate and backfill each downstream dam face to repair rodent holes and erosion areas.
• Preventative measures – place downstream embankment rock slope protection with wire mesh underlayment to prevent future rodent burrowing.

What to Expect

• During the project, DWR will be operating construction equipment and transporting materials to the site. Some localized noise and increased activity may be expected.

  The Project will include (See map):

• Bethany Reservoir State Recreation area is open to the public. For more information, visit the CA Parks website.
• Parking lot two at Bethany Reservoir’s Forebay Dam is temporarily closed. Parking lot one is available.
• Temporary closure of a one-mile section of the 1.8 mile trail along the reservoir.