The primary objectives of the Los Vaqueros Expansion Project Phase 2 are:

• Increase reliability of Delta water supplies for municipal, industrial and agricultural purposes.
• Increase water supply reliability for water providers within the San Francisco Bay Area. 
• Enhance water supply reliability and operational flexibility for environmental; water management purposes including refuge water supplies within and south of the Delta.

Potential Benefits:

• Increased water supply reliability ranging from 44,000 to 504,000 acre-feet per year in dry periods. 
• Added emergency water supply storage for Bay Area agencies ranging from 80,000 to 120,000 acre-feet per year. 
• Increased environmental water supply ranging from 50,000 to 790,000 acre-feet per year. 
• Improved quality of water delivered to municipal and industrial water treatment facilities.

The watershed is located in the foothills between Livermore and Brentwood east of San Francisco.

The original Los Vaqueros Dam was completed in 1998. At that time, the reservoir had a capacity of 100,000 acre-feet. In 2012, the dam was raised 34 feet, and is now 226 feet high (from toe to crest). It can currently store up to 160,000 acre-feet of water in the first phase of expansion. It is the largest reservoir in the Bay Area.

The Contra Costa Water District owns the dam, pipelines, associated pump stations and the watershed. CCWD ratepayers funded both the original construction of the dam and the expansion.

Review available environmental documents.

Learn more about funding and our local agency partners.

2020 – 2022 Permitting, local agreements, and design

Summer 2022 Final California Water Commission funding agreement