State Water Project Archives

Urban Water Management Plan-Water Authority-Primary photo-Colorado River Aqueduct

Value of Water, Explained

March 17, 2025/in Education, Features /by Jordan Beane

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.

Where does San Diego’s Water Come From?

San Diego County has three main sources of water: The Colorado River (61%), local supplies (33%) and the State Water Project (6%). Together these three categories provide a diversified water supply to ensure we’ve got abundant options to keep the water flowing.

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.

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.

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.

The Colorado River Basin provides essential water supplies to approximately 40 million people and 30 Tribal Nations, nearly 5.5 million acres of agricultural lands, and habitat for ecological resources across parts of several Western states (including Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming) and Mexico.

How far does water travel to reach San Diego?

Water can travel up to a thousand miles before coming out of your tap. Snow and rain falls in the Rocky Mountains and travels to the region through the Colorado River. For the State Water Project, rain falls in northern California over 500 miles from San Diego and travels to the region through water infrastructure. In addition, the region has a growing array of local water supplies, including desalinated seawater and recycled water.

What does San Diego’s water infrastructure look like?

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.

Karla Sanchez-Engineers Week-Senior Engineering Technician

Water Authority Senior Engineering Technician Karla Sanchez. Photo: San Diego County Water Authority

How many facilities does the Water Authority operate to keep our system running?

With 1,600 structures and over 100 flow control facilities, the Water Authority’s countywide infrastructure is vital to provide San Diego with a safe and reliable source of water.

What is leading to rate increases?

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.

What else is the Water Authority doing to help the region understand its role?

The world of water is a complex one that needs color and context. That’s why, over the past few months, the Water Authority has developed a bilingual (English/Spanish) outreach strategy to tell residents across the region who we are and what we do. This program delivers targeted messaging across multiple channels, focusing on the value of water, infrastructure investments, climate adaptation and the people who make the water systems work. We hope that this effort will provide a deeper appreciation of the Water Authority and a better understanding of everything we do.

Where San Diego’s Water Comes From, Explained

February 5, 2025/in Education, Features, Uncategorized /by Jordan Beane

Water in California, while always a hot topic, entered the national spotlight at the start of 2025. Where the San Diego region’s water comes from, how it’s provided and who’s in charge of what are big questions that water professionals address every day.

What are the biggest sources of water for San Diego County?

In 2024, about 60% of the region’s water supplies were from the Colorado River, about one-third were from local sources and the rest was from Northern California through the State Water Project. The State Water Project is operated by the State of California and is separate from the Central Valley Project operated by the federal government.

Regardless of the source, all the water delivered to homes and businesses across the region meets strict state and federal quality standards.

How has our region’s water supply changed over the years?

In 1991, San Diego County got 95% of its water from the Metropolitan Water District (MWD) in Los Angeles, leaving the region’s water supply outside of San Diego’s control. A lack of local resources left the region susceptible to supply cutbacks from its major single major source. In 1991, MWD imposed an supply reduction of 31%, prompting the San Diego region’s civic and business leaders to demand greater investments and increased control over the county’s water future. In the following three decades, the Water Authority invested roughly $3 billion in regional water reliability projects. That included cementing the largest water conservation-and-transfer deal in U.S. history to secure conserved water from the Imperial Valley, partnering with a private company to build the nation’s largest seawater desalination plant and super-sizing San Vicente Reservoir by raising the height of the World War II-era dam. Now San Diego has a locally controlled and diversified water supply to make sure the taps always turn on.

SDCWA’s water portfolio over the years.

Why doesn’t San Diego County use much groundwater?

Before 1947, the San Diego region relied heavily on local surface water runoff in normal and wet years, and on groundwater pumped from local aquifers during dry years when stream flows shriveled. As the economy and population grew exponentially, local resources became insufficient to meet the region’s water supply needs, and the region increasingly turned to imported water supplies. Today, groundwater is a small but important resource, especially in places like the South Bay where the aquifers are relatively large. Overall, it accounts for about 5 percent of the region’s water supply portfolio.

What is being done to create additional water supply here in the region?

Coordinating with 22 member agencies to develop long-term, local water reliability is a key component of the Water Authority’s mission. In fact, a growing number of local water sources across the San Diego region are managed by local retail agencies — and they are critical to ensuring long-term supply reliability. Local projects reduce demand on imported supplies and provide local agencies with more control.

In San Diego County, agencies are investing in seawater desalination, water recycling and water purification to create the water reliability our region needs to thrive.

What does the future of water look like for San Diego County?

Even in very dry years like 2025, regional investments mean there’s sufficient water to sustain our economy and quality of life. In fact, the region has done such a good job securing water, that it’s talking with other agencies across the Southwest about selling some of locally controlled water to combat rate increases in the county and support the larger regional economy.

For more information about San Diego’s water sources, click here.

Opinion: A Call for Balanced Water Management in California

September 19, 2024/in California and the U.S., Home Headline, Media Coverage /by Chelsea Campos /Maven's Notebook

The draft environmental impact statement for the long-term operation of the federal Central Valley Project and State Water Project has raised alarm bells for farmers and urban water users who depend on these water projects. Based on the document released July 26 for public review, the U.S. Bureau of Reclamation, Fish and Wildlife Service and National Marine Fisheries Service seem to be pushing a regulatory agenda that prioritizes environmental objectives to the detriment of agricultural, municipal and industrial water needs.

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EXPLAINER: Delta Conveyance Project

September 3, 2024/in California and the U.S., Media Coverage /by Kylie Capuano /Maven's Notebook

Trans-Delta System, Peripheral Canal, Bay Delta Conservation Plan, California Water Fix, and now, the Delta Conveyance Project – the idea of a canal to route water around the Delta is certainly not new. It was initially thought of as part of the master plan for the State Water Project but wasn’t included in the initial construction due to cost considerations. In the 1980s, plans were begun to construct such a canal, but it was put to a statewide vote, which was soundly defeated due to concerns about its potential impact on the Delta’s ecosystem and native fish populations.

Despite past setbacks and strong opposition, the idea of constructing a bypass around the Delta was never entirely abandoned. Over the years, it has continued to be a topic of intermittent discussion, with geography playing a significant role in the level of opposition. The most vocal opponents are often found in the northern part of the state, particularly within the Delta itself.

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Column: DWP’s New Leader Wants to Shake Things Up. It Won’t Be Easy

June 17, 2024/in California and the U.S., Media Coverage /by Chelsea Campos /Los Angeles Timesby Sammy Roth

An honest-to-goodness map of the American West would show L.A.’s tentacles everywhere.

You’d see canals — the Los Angeles Aqueduct, running along the base of the Sierra Nevada, carrying water from the Owens River; the State Water Project, meandering through the San Joaquin Valley, supplying many Southern California cities and farms; and the Colorado River Aqueduct, cutting through the desert on its mission to deliver water from desert to coast.

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Jennifer Pierre Wants More Water

May 6, 2024/in California and the U.S., Home Headline, Media Coverage /by Chelsea Campos /Politicoby Camille Von Kaenel

Despite this year’s deep snowpack, record-setting rainstorms and consequently full reservoirs, the 27 water agencies she represents as general manager of the State Water Contractors are getting just 40 percent of their contracted deliveries, as we reported earlier this week.

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How A ‘Death Trap’ For Fish In California’s Water System Is Limiting The Pumping Of Supplies

May 3, 2024/in California and the U.S., Media Coverage /by Gayle Falkenthal /Los Angeles Timesby Ian James

Giant pumps hum inside a warehouse-like building, pushing water from the Sacramento-San Joaquin River Delta into the California Aqueduct, where it travels more than 400 miles south to the taps of over half the state’s population.

But lately the powerful motors at the Harvey O. Banks Pumping Plant have been running at reduced capacity, despite a second year of drought-busting snow and rain.

The reason: So many threatened fish have died at the plant’s intake reservoir and pumps that it has triggered federal protections and forced the state to pump less water.

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Why No One Won in This Year’s Water Wars

May 2, 2024/in California and the U.S., Home Headline, Media Coverage /by Chelsea Campos /Politicoby Camille Von Kaenel

EVERY DROP COUNTS: California had (is still having, amazingly) a really good water year. But all the rain and snow is doing almost nothing to lubricate the state’s perpetual conflicts between fish and farms.

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California Increases Water Allocation After Wet Winter, but Fish Protections Limit Pumping

April 24, 2024/in California and the U.S., Home Headline, Media Coverage /by Chelsea Campos /Los Angeles Timesby Ian James

With runoff from this year’s snow and rain boosting the levels of California’s reservoirs, state water managers on Tuesday announced plans to increase deliveries of supplies from the State Water Project to 40% of full allotments, up from 30% last month.

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