2. Where Does Water Come From?
San Diego imports 80% to 90% of its
water
San Diego’s imported water supply comes from Northern
California and the Colorado River Basin.
A small percentage of the supply is from local sources:
Groundwater & Reservoirs- 10%
Recycling - 3%
San Diego’s Average Rainfall is less than 10” per year.
California’s Average Rainfall is greater than 17”
3. Imported Water: State Water
Project
Water from Northern
California is brought to us by
the California Aqueduct.
The California Aqueduct is
444 miles-long and carries
the water through the San
Joaquin Valley to Southern
California.
In addition to the California
Aqueduct, the SWP consists
of:
Approximately 22 dams
and reservoirs
California Aqueduct
1 Delta pumping plant
4. State Water Project: Customers
The SWP provides irrigation water to farms in the San Joaquin
Valley, and is a major supplier for
Los Angeles County
Riverside County
San Bernardino County
San Diego County
Other parts of Southern California
Cities in Napa and Solano counties through the North Bay
Aqueduct
Santa Barbara and San Luis Obispo counties through the Coastal
Aqueduct
Alameda and Santa Clara counties through the South Bay
Aqueduct.
6. Colorado River
In addition to California, the
Colorado River is a water
source for Colorado, Utah,
Wyoming, New Mexico,
Nevada, and Arizona
Water allotments are also
given to Indian Reservations
and Mexico
7. Colorado River Aqueduct
Consists of:
2 reservoirs
5 pumping plants
63 miles of canals
92 miles of tunnels
84 miles of buried
conduit and siphons
Has a capacity of 1.3 million
acre-feet per year
8. Water Distribution
Metropolitan Water District (MWD) imports water from
Northern California and the Colorado River and serves 19
million people in 6 counties.
Metropolitan Water District Sells to SDCWA
SDCWA Sells to SDC Member Agencies - Padre, Carlsbad,
Rincon, etc. (25 total members) – 3 million residents
SDCMA Distributes to general population
The water that we purchase is a blend of Colorado & SWA
9. Water Distribution
Water is transferred to the
San Diego treatment plants
at Miramar, Alvarado and
Otay reservoirs, via pipelines
operated by San Diego
County Water Authority.
10. Colorado River-Decreasing Water
Supply
California takes approximately 5.2 million acre feet/year from
the Colorado River, though we are only allotted 4.4 maf/year.
We’ve been able to take more than our allotment for a number
of years, because other states were not using their entire
allocation.
Growing demand in other areas has resulted in other states
using more of their allocation.
11. Environmental Limitation: State
Water Project
Large pumps near the
Sacramento River Delta,
which send water down the
State of California, have
been identified as causing
harm to a tiny fish, the Delta
Smelt.
Levees very fragile
Decline in native species
Water quality issues
2/3 of this water goes to
SoCA.
12. Where does it go
The average household uses between 45% to 50% of their water for
outdoor use.
Examples:
Hosing off hardscapes
Children playing with the hose or water toys
Washing your car without a bucket or trigger nozzle
Landscape Irrigation