Water Use

How Are We Doing?

Water use received a thumbs-down because daily residential water consumption in San Diego County increased by 8.3% from 84 gallons per capita in 2017 to 91 gallons in 2018. Water use has increased since the state-wide water restrictions were lifted in 2017, though remain below pre-drought levels. The 2018 financial year saw substantially lower rainfall, which likely contributed to the increased water use in the period. All but 3 of the county's 24 water districts increased their estimated municipal and industrial water use from 2017 to 2018. Want to know more about what we're measuring?

thumbs down

Worsened more than 1 percent from 2017 to 2018

Data Sources: National Oceanic and Atmospheric Administration, California Nevada River Forecast Center, Monthly Precipitation Summary, 2018; San Diego County Water Authority, 2019

In March 2019 California was officially declared drought free, ending a drought that began in 2011. In 2018, despite the increased rainfall across the state, San Diego County's rainfall (as measured at the San Diego International Airport), was only 3 inches, 74% below the 2017 precipitation total. Residential water use per capita in 2018 remained lower than historical rates, however, the last 2 years show a clear upward trend.

Why is it Important?

High quality of life means a clean environment, a thriving economy, and an equitable place for all to enjoy.

  • The San Diego County Water Authority is expanding its partnership with San Diego Gas & Electric (SDG&E) to increase the availability of devices that save both water and energy for thousands of income-qualified residents across the region.
  • Water reliability is a crucial component to maintaining a thriving economy in the San Diego region, and investments in water infrastructure benefit the economy. According to a 2018 study conducted by the San Diego Regional Economic Development Corporation, investments in water reliability infrastructure over the past 20 years have had a $1.8 billion economic impact and have supported 1,475 jobs annually.

Data Source: San Diego County Water Authority, 2018

San Diego County's water supply has diversified significantly over the last couple of decades. While the San Diego County Water Authority has decreased the region's reliance on water from the Metropolitan Water District which serves parts of Los Angeles, Orange, San Diego, Riverside, San Bernardino and Ventura counties, the region still remains heavily reliant on water from the Colorado River (through transfers from the Metropolitan Water District, Imperial Irrigation District, the All-American and Coachella Canal Lining and the San Luis Rey Water Transfer).

Data Source: State Water Resources Control Board, Urban Water Supplier Report, 2019

*Sweetwater Authority is comprised of the South Bay Irrigation District and National City. The dataset excludes the City of Del Mar, the City of Oceanside, Camp Pendleton Marine Corps Base and the Yuima Municipal Water District.

In Q4 of 2018, residents in the Sweetwater Authority area (National City and South Bay) had the lowest residential water use in San Diego County. Santa Fe Irrigation District used 363 gallons per capita/day, the most water per capita in San Diego County.

Data Source: San Diego County Water Authority, 2018

*This data includes agricultural water use served by local water agencies.

In 2018, National City had the lowest municipal and industrial (M&I) water use at 78 gallons per capita daily. Yuima's high per capita M&I potable water use occurs because a large amount of water used for horticultural irrigation is classified as M&I, and the district services a small population (less than 2,000 people).

Regional Response


The San Diego region is making significant commitments to water efficiency and recycling. Pure Water San Diego, a large scale wastewater purification program currently in its early stages, will provide one-third of the City of San Diego's local water supply by 2035. The San Diego region is also home to the nation's largest desalination project, The Carlsbad Desalination Plant, which produces close to 50 million gallons of fresh, potable water a day for the County.


Green Street projects are low impact development roadway improvements that aim to sustainably address stormwater runoff. San Diego County has made policy-based commitments to developing Green Streets by issuing guidelines to leverage design resources and streamline projects. Many jurisdictions have already expanded the implementation of Green Streets.


The San Diego Regional Climate Collaborative held a Climate and Water Summit in October 2018 at the Central Library in downtown San Diego. More than seventy guests including water practitioners, climate researchers, and other climate adaptation professionals from throughout the region came together to discuss the state of adaptation in the water sector.

The San Diego County Water Authority, the City of San Diego, and the County of San Diego originally formed the Regional Water Management Group (RWMG) to fund, guide, and manage the development of the 2007 Integrated Regional Water Management (IRWM) Plan. The RWMG is now responsible for the day-to-day administration and implementation of the San Diego IRWM Program. The RWMG meets bi-weekly to research, review, discuss, and formulate ideas and concepts for IRWM Plan implementation activities.



What Are We Measuring?

We measure year-over-year residential, and municipal and industrial water use per person in San Diego County by water agency. In addition, we compare per capita estimated residential water use to the year’s rainfall at the San Diego International Airport. Learn more about the data.