California's Water: Facts on Storing Water

Reservoirs and Storage

• There are over 1,000 local, state and federally owned and operated surface water storage reservoirs in California.

• State reservoirs: 22
• Federal reservoirs: 44
• Joint state-federal reservoirs: 3
• Local: Around 1,000 (many very small)

• The 200 biggest reservoirs have a combined capacity of more than 41 million acre-feet.

• Reservoirs are operated for a number of purposes:

• Flood control
• Water supply
• Hydroelectricity generation
• Water quality improvement
• System flexibility
• Reliability against droughts / catastrophic events

• Key state and federal reservoirs were built 40 to 60 years ago.

• Some locally owned reservoirs were built 80 to 100 years ago.

• Reservoirs vary in size, structure and purpose. Some reservoirs were formed by building dams across active rivers or streams. Others were constructed off-stream, and water must be diverted into them from a nearby river or water source.

Key Facts about the State Water Project

• Built in 1960s
• Includes 22 dams and reservoirs
• Extends 600 miles from Northern to Southern California
• Delivers about 2.3 million acre-feet of water annually to parts of the Bay Area, San Joaquin Valley and Southern California

Key Facts about the Central Valley Project

• Built in the 1930s
• Includes 20 reservoirs and 500 miles of canals.
• Delivers about 5.6 million acre-feet of water annually to agricultural and urban customers.

Key Local Water Supply Projects

• All-American Canal – delivers 3 million acre-feet of Colorado River water to users in the Imperial Valley
• Colorado River Aqueduct – delivers 1.2 million acre-feet of water annually to urban Southern California
• Los Angeles Aqueduct – delivers 200,000 acre-feet of water annually
• Mokelumne Aqueduct – delivers 364,000 acre-feet of water to the East Bay area
• San Francisco Hetch Hetchy Project – delivers 330,000 acre-feet annually