For more than 80 years, the Water Authority and its 22 member agencies have worked together to deliver safe and reliable water to our community. Thanks to our coordinated efforts and investments, the 3 million people who call San Diego County home have the water they need for generations to come.
Your Water
Understanding Water in San Diego County
Where does water in San Diego County come from?
61%
Colorado River
33%
Local
6%
state water project
61% Colorado River
Most of the region’s water from the Colorado River is generated through increased conservation measures on farms and canals in the Imperial Valley.
33% Local supplies
Seawater desalination, recycled water, water purification, and brackish groundwater, are sources of local water supplies in the San Diego region. Local water agencies have worked to maintain and create these supply sources, with support from the Water Authority. The Water Authority also invested in the Carlsbad Seawater Desalination Plant, brought online in 2015.
6% State Water Project
The Bay-Delta is the hub of the State Water Project, a water storage and delivery system that is owned by the State of California and operated by the California Department of Water Resources. The Water Authority purchases State Water Project supplies through the Metropolitan Water District.
How far does water travel to get to San Diego?
Up to
1,000
Miles
1,000+ Miles
Snow and rain falls in the Rocky Mountains over 1,000 miles from San Diego and travels to the region through the Colorado River.
Rain falls in northern California over 500 miles from San Diego and travels to the region through the State Water Project.
In addition, the region has a growing array of local water supplies, including desalinated seawater and recycled water.
The region’s aqueduct delivery system contains how many miles of large-diameter pipeline?
300+ MILES
More than 300+ Miles
Imported water arrives from the Colorado River and State Water project from pipelines that are owned and maintained by Metropolitan Water District and the State of California respectively. The Water Authority takes ownership of pipelines just south of the Riverside-San Diego county borderline and maintains more than 300 miles of pipelines in San Diego County that transport water throughout the region. Local water agencies operate thousands of miles of smaller pipelines that deliver water to homes and businesses.
YOUR WATER DISTRICT
The Water Authority is a water distributor. We get water from major sources and then supply it to local water agencies who then deliver it to your homes and businesses.
To find your local agency, view the map below.
How many facilities does the aqueduct system contain?
1,600
STRUCTURES
100+
flow-control facilities
1,600 structures
Major facilities associated with the delivery system include Olivenhain Dam and it’s 24,000 acre-foot reservoir, the Twin Oaks Valley Water Treatment Plant, metering and control facilities, seven pump stations, hydroelectric generating facilities, pressure control stations, regulatory structures, an operations and maintenance center and administrative office.
100+ flow-control facilities
Major facilities associated with the delivery system include Olivenhain Dam and it’s 24,000 acre-foot reservoir, the Twin Oaks Valley Water Treatment Plant, metering and control facilities, seven pump stations, hydroelectric generating facilities, pressure control stations, regulatory structures, an operations and maintenance center and administrative office.
How many acres of right-of way does the Water Authority maintain?
1,400
acres
1,400 Acres
"Right-of-way" is land that the Water Authority owns or has rights to use to operate, maintain or repair agency facilities.
Managing the right-of-way to preserve the Water Authority’s ability to quickly access or repair vital water facilities when needed is a crucial ongoing effort.
Size of pipeline that the Water Authority maintains VS. home plumbing
10 feet
6 feet
4 feet
1/2 inch – 1 inch
Large enough for an elephant to walk through.
Large enough for a human to walk through.
Large enough for A mountain lion to walk through.
Home Plumbing Pipes
Large enough for a sand crab to fit through.
Controlling Costs
rates & Affordability
Water rates are rising across the state for a variety of reasons, including inflation that is driving up the cost of items like electricity, steel and chemicals needed for water delivery and treatment.
The Water Authority and its member agencies are not immune from those impacts. In fact, San Diego County’s strategic investments in supply reliability, coupled with the work to maintain the aqueduct system, means that residents and businesses will pay more for water in future years.
The good news is that even during long dry spells, the Water Authority can meet the regional demand for water that sustains our economy and quality of life.
Water Authority Budget Breakdown
64%
Water Purchases & Treatment
16%
DEBT SERVICE
10%
capital improvement program expenditures
7%
operating departments
2%
other and grants
1%
equipment replacement
Major Factors Behind Raising Water Rates in 2025
+3%
Water Authority Finance & Infrastructure
+4% Metropolitan Water District (EXTERNAL FACTOR)
+3% supply costs (EXTERNAL FACTOR)
+4% Detachment of two member agencies (EXTERNAL FACTOR)
To understand your water bill, refer to your LOCAL RETAIL agency. Rates vary by agency based on numerous factors.
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