Timeline Highlights Timeline

Before the formation of West Basin Municipal Water District, coastal Los Angeles leaders and community members found there was a need for a public entity dedicated to managing and protecting local water supplies. As a result, West Basin was formed in 1947 with the task of making local water supplies more reliable by seeking new water sources and protecting groundwater supplies through reduced pumping. Since then, the District has been delivering on its mission of water reliability and establishing drought resiliency through balanced and cost-effective water supply diversification.

This year, West Basin celebrates more than seven decades of water reliability. Throughout 2022, the District will commemorate key moments in its history in recognition of this major milestone. To learn more visit:

West Basin 75th Anniversary

Cool Timeline

Salt Water Begins to Intrude

The growing railroad and oil industries led to a population boom in the region, which eventually increased demand on the local groundwater supply. Due to over pumping of groundwater, groundwater drops below sea level causing salt water to intrude into the groundwater basin and local drinking water wells.

West Basin Municipal Water District is Formed

West Basin Municipal Water District is voted into existence in November 1947 after two attempts:

  1. Jan. – First attempt to form West Basin Municipal Water District fails.
  2. Nov. – Second attempt to form West Basin Municipal Water District succeeds by an 8:1 margin.
  3. Its mission was to both protect the existing water supply (groundwater) and increase reliability by identifying new supplemental supplies of water.

West Basin Joins Metropolitan

On June 8, 1947, West Basin joins the Metropolitan Water District of Southern California, the regional wholesale water agency that owns and operates the Colorado River Aqueduct, which would later provide supplemental water supplies to the service area.

First Seawater Barrier Project Delivery

In partnership with the Los Angeles County Flood Control District, the West Basin Sea Water Barrier Project began with 23 recharge wells that pump freshwater into the ground to protect local groundwater aquifers from sea water intrusion.

First Drop of State Water Project Water to West Basin

West Basin receives its first delivery of imported drinking water from Northern California via the State Water Project, which is owned and operated by the Department of Water Resources.

Unprecedented Drought in California

California experiences one of the most serious droughts in its history. West Basin’s innovative leadership determines that the area’s future demands for water would be met by developing supplies from multiple sources: ground and imported water, conservation, and eventually, water recycling.

Water Recycling Facility Completed

West Basin Water Recycling Facility construction is complete, delivering water to its first customer at the El Segundo Lakes golf course adjacent to the West Basin recycling facility. West Basin brings four recycling facilities online: West Basin Water Recycling Facility, Chevron Nitrification Plant, West Coast Basin Barrier Project, and Exxon/Mobil Nitrification Plant.

100 Billion Gallons of Recycled Water

West Basin produces 100 billion gallons of recycled water and is the only facility in the world to produce five types of customer tailored, fit-for-purpose recycled water.

Edward C. Little Water Recycling Facility Reopens
Edward C. Little Water Recycling Facility Reopens

After being closed to the public due to major improvements, West Basin celebrates the re-opening of the Edward C. Little Water Recycling Facility. To date, West Basin has invested over $700 million in its recycled water system over the course of several expansions, including more than $277 million in grants and outside investments:

  • Phase I | 1995: Water recycling plant and two site-specific nitrification facilities are brought online.
  • Phase II | 1999: Integrated membrane system of microfiltration and reverse osmosis is added.
  • Phase III | 2004 : Chevron boiler recycled water feed expansion. Carson water recycling plant brought online.
  • Phase IV | 2006: Title 22 and seawater intrusion barrier expansion. $65 million invested.
  • Phase V |2013: Title 22 and seawater intrusion barrier upgrades and expansion.
  • Current improvements | 2019: Water education center and recycled water pump station improvements.
Securing Our Water Future

West Basin recycled water continues to thrive, and received $3.8 million in federal funding for the North Gardena Recycled Water Lateral and Mills Memorial Park Recycled Water Lateral project. Both projects will benefit priority communities in the West Basin service area by providing an ongoing, reliable source of recycled water to help maintain beautiful green spaces at local public parks and schools.


Early Years
1850s – 1950s | Formation and the Early Days
1854 First water wells drilled in the West Basin.
1918 Salt water intrudes into coastal aquifers in Redondo Beach area.
1922 Groundwater drops below sea level, salt water intrudes into drinking water wells in El Segundo.
1931 Following approval of a $220 million dollar bond, Colorado River Aqueduct construction begins.
1940s Industry increases pumping for World War II.
1940 Redondo Beach High School – salt water contaminates groundwater well.
1940s Planning for State Water Project begins.
1941 Colorado River Aqueduct is complete.
1942-1944 West Basin Survey Committee formed to determine salt water damage to the groundwater supply.
1944-1945 Production is 69,476 acre feet a year.
1945 West Basin Groundwater Conservation Group (WBGCG) formed by representatives from cities, private water utilities and local industries.
1945 WBGCG releases report showing more water being withdrawn from groundwater basin than being naturally replenished and overdraft is 29,000 acre feet. Suggested corrective measures include reduce the overdraft of groundwater, educating the public about the water shortage problem and finding a source of supplemental water, including reclaiming water from the San Fernando Valley and the Owens Valley.
1946 Legal action taken to arbitrate water rights and control overdraft in California Water Service Company, et al. v. Compton, et al., L.A. County Superior Court, Case # 506,806.
1946 West Basin Water Association organizes and initiates study under Harold Conkling to determine supplemental water source needed to prevent overdraft of groundwater supplies. Conkling’s report recommends the use of Colorado River water as supplemental supply. West Basin needs majority of public to vote in support of its formation as a Municipal Water District and become member of Metropolitan Water District of Southern California (MWD).
1947 Mayors of five South Bay cities form the South Bay Water Committee.

  • Jan – First attempt to form West Basin Municipal Water District fails.
  • Nov – Second attempt to form West Basin Municipal Water District succeeds by an 8:1 margin.
1948 U.S. Geological Survey releases water supply report showing fresh groundwater is threatened by salt water intrusion.

  • West Basin becomes member of Metropolitan Water District of Southern California.
  • Following formation of West Basin, a five-member Board of Directors is elected and sworn into office. First board includes Robert E. Austin, William C. Farquhar, Russell T. Hutchins, Ralph W. Pritchard, and August H. Riess.
  • Kenneth K. Wright is appointed Attorney of the District.
  • Carl Fossette is appointed General Manager of the District.
1949 Report on reclamation is prepared for L.A. County Board of Supervisors, outlining opportunities for using reclaimed water.

  • First supply of imported water used in West Basin service area.
1950 In an effort to control salt water intrusion and determine effectiveness of maintaining a fresh water pressure ridge along the coast, County Flood Control begins fresh water injection tests into abandoned water well in Manhattan Beach.

  • $750,000 grant allocated by California State Legislature to start injection well testing.
1951 Legislature amends the County Flood Control District Act to authorize establishment of conservation zones.

  • Salt water intrusion increases in the West Basin.
1952 Report of Referee in West Basin adjudication is filed with the Court, ordering water producers to reduce groundwater extractions, requiring purchase of supplemental water to offset reduced pumping.

  • Major aqueduct expansion required due to tremendous growth of Southern California following World War II.
1953 Test barrier, paralleling Manhattan/Hermosa Beach area, development begins.

  • Ralph B. Helm appointed Attorney for the District.
1954 Zone II is established to carry on barrier testing started by the State.
1955 Forty-six major groundwater producers in the West Basin voluntarily agree to restrain their groundwater extractions to 56,963 acre feet per year.

  • California State Legislature adopts the Water Replenishment District Act and the Recordation of groundwater Production Act.
1956 Second adjudication action filed to gain jurisdiction over new producers and those who may have been overlooked during the service of the original action. Court orders continuation of the West Basin Reference to update physical facts and directs State Water Rights Board to make these determinations.
1958 Second report was prepared for the County Board of Supervisors, affirming findings of first report from 1949. It proposes construction and operation of water reclamation plant at Whittier Narrows to demonstrate the feasibility of wastewater reclamation.
1959 Central and West Basin Water Replenishment District is formed to purchase supplemental water to replenish the depleted groundwater basins.
1959 Construction begins on State Water Project.
1960s – 1970s | Protecting Groundwater
1960 Draft of Continued Reference Report on West Basin Adjudication is filed with the Superior Court and recommends limiting groundwater production, providing exchange for water pool, appointing a Watermaster to administer the terms and conditions of the Court, and continued jurisdiction by the Court over this Action.
1961 Aqueduct expansion complete, bringing imported water delivery capacity to 1,180,000 acre feet annually. Court enters judgment in the original West Basin adjudication requiring groundwater production to be reduced to 64,042 acre feet.
1963 Development of test barrier paralleling the coast of Manhattan/Hermosa Beach is complete.
1966 Court enters second judgment against additional West Basin pumpers overlooked in first Action. All were made party to the terms of the original Judgment and the annual pumping was adjusted to 64,468 acre feet. Work begins on the Dominguez Gap Barrier Project to protect lower fresh water aquifers in the southeast area of the West Coast Basin from salt water intrusion.
1968 Flood Control District completes West Coast Basin Seawater Barrier consisting of 94 recharge wells injecting 50 million gallons of fresh water daily and 256 observation wells protecting groundwater supplies from salt water intrusion.

  • City of Los Angeles Department of Water and Power constructs activated carbon gravity flow pilot test plant at Hyperion Sewage treatment plant to determine whether water from Hyperion could be reclaimed.
1971 Dominguez Gap Barrier Project begins, consisting of 29 injection wells.
1972 Special water conservation area operated by the County Flood Control District for West Coast Basin ends. Entire cost of financing barrier injection programs hereafter must be supported by the water pumpers.

  • West Basin Municipal Water District asks water users to help and asks Water Replenishment District to get court approval to permit increased pumping, temporarily.
  • Court grants Ex Parte order to permit additional over-extractions to the West Coast Basin beyond the 10% allowed in the judgment.
  • To maintain emergency storage at Metropolitan’s Lake Matthews, West Basin Municipal Water District informs Metropolitan that pumpers have agreed to pump more water and use less imported water.
  • West Basin receives delivery from State Water Project through the Jensen Treatment Plant. State Water Project replaces Colorado River water as main source of supplemental water in West Basin.
1973 To prevent salt water intrusion at the southern end the County Flood Control District, additional facilities are recommended for West Coast Seawater Basin Barrier Project.

  • In response to new requirements of the State Health Department, West Basin Water Association submits a basin-wide plan to monitor quality of well water supplies pumped for domestic use.
1974 Metropolitan Water District commences delivery of State Water Project in lieu of the Colorado River to West Basin for injection into seawater barriers.

  • Water Replenishment District terminates participation in the proposed County Water Recycling Project at Playa de Rey.
  • Hyperion project is terminated due to cost of material and labor.
1975 Eleven new injection wells complete in West Coast Basin Seawater Barrier Project, bringing total number of injection wells to 105.
1976 In FY 1975-76, West Basin Municipal Water District purchases 168,555 acre feet of water from Metropolitan Water District.

  • Metropolitan Water District suspends the delivery of water for spreading grounds due to severe drought in Northern and Central California to aid drought-stricken farmers rather than for Southern California water replenishment.
Drought cms
1980s – 1990s | Drought and Local Supply
1987-1992 California experiences one of its most serious droughts in history.
1988 Congress enacts Federal Disaster Assistance Act of 1988, due to extent and severity of drought.

  • Water shortages occur in 45 California counties.
1989 Ten million people under drought-induced water rationing or conservations programs.
1990 – 1996 Rich Atwater joins West and Central Basins as General Manager.
1991 West Basin and City of Los Angeles reach agreement to deliver treated sewer water from the City’s Hyperion plant to a new West Basin Water Recycling Facility in El Segundo.
1994 West Basin/Hyperion Pump Station is built to pump water to facility.
1995 West Basin Water Recycling Facility construction complete, delivering water to first customer, El Segundo Lakes golf course.

  • West Basin Water Recycling Facility begins injecting water into the seawater barrier to protect the groundwater supply from salt water intrusion.
  • West Basin brings four recycling facilities online: West Basin Water Recycling Facility, Chevron Nitrification Plant, West Coast Basin Barrier Project, and Exxon/Mobil Nitrification Plant.
1996 West Basin Water Recycling Facility visitor’s center is complete.

  • Phase I Water Recycling Facility begins operating at full capacity, producing 15 million gallons a day.
  • Phase II Water Recycling Facility construction begins.
1997 Phase II Water Recycling Facility complete, expanding production capacity of tertiary and barrier water.
1998 West Basin hosts first Water Harvest festival at the Water Recycling Facility. Hollywood Park in Inglewood is 100th recycled water customer.
1999 West Basin increases percentage of near-distilled quality sewer water injected into the seawater barrier from 25 to 50 percent.

  • West Basin completes construction of Juanita Millender-McDonald Water Recycling Facility in Carson, the first on-site, ultra-pure sewer water purification plant in the nation.
Pie Chart
2000s – 2010s | Diversification of Supply
2000 Phase III of the Water Recycling Facility expands capacity of microfiltration and reverse osmosis.
2004 Department of Water Resources awards West Basin $9 million Proposition 13 grant for expansion of its water recycling facilities.

  • Construction begins on Phase IV Expansion of Water Recycling Facility.
​2005 West Basin’s Water Recycling Facility celebrates 10th anniversary and the following achievements:

  • Phases of construction make it the largest facility of its type in the nation;
  • The facility is the only water purification facility in the world to produce 5 types of designer waters;
  • 8 billion gallons of water produced annually;
  • 68 miles of pipeline in the future Harbor/South Bay Water Recycling Project;
  • 79 miles of existing recycled water pipeline;
  • 206 recycled water users; and
  • 25,000 children participated in the Plant Protector Water Exploration tours.
2006 West Basin adopts Conservation Master Plan as a guide for regional investments and translates conservation goals into tangible initiatives for residents, businesses and various levels of government.

  • West Basin and Central Basin become separate entities.
2006 West Basin celebrates its 60th anniversary and renames its water recycling facility after long-time Director Edward C. Little.
2007 Construction complete on Phase IV Expansion, increasing recycled water production by 15 million gallons a day.
2008 West Basin produces its 100 billionth gallon of recycled water.
2009 West Basin and Water Replenishment District sign agreement to serve 100% purified recycled water to the West Coast Barrier.
2010 West Basin reaches 350 recycled water customer connections.
2012-2016 California declares a statewide drought emergency.
2013 Phase V expansion is completed to increase recycled water injected into the Barrier with the goal of achieving 100 percent recycled water injection and providing a more reliable, high-quality source of water to the aquifer.
2018 West Basin produces its 200 billionth gallon of recycled water.
2019 West Basin Director Gloria D. Gray begins serving two-year term as chairwoman of the Metropolitan Water District of Southern California’s Board of Directors.
2019 The Edward C. Little Water Recycling Facility Water Education Center is re-dedicated after undergoing major improvements.
2019 California adopts AB 1668 and SB 606, which set permanent water-consumption goals to prepare for future droughts and climate change, effective January 2019.

  • These bills established an indoor, per-person water use goal of 55 gallons per day until 2025.
2019 Colorado River users agreed on a Drought Contingency Plan to address dwindling reservoir levels and enable the negotiation of long-term solutions to challenges on the river.

Check Presentation
2020s – Present | Securing Our Water Future
2020 West Basin celebrates its 25th year of recycled water innovation, producing more than 225 billion gallons of recycled water since 1995.

  • Awarded Utility of the Future Today for its successful recycled water program from Water Environment Federation (WEF).
  • Awarded Regional Best Project Award in the Water/Environment category from Engineering News-Record (ENR) for Hyperion Secondary Effluent Pump Station Improvements (HSEPS) project.
2020 West Basin announces its first delivery of recycled water to SoFi Stadium and Hollywood Park, home of the Los Angeles Rams and Los Angeles Chargers, in the city of Inglewood. This project provides 26 million gallons of recycled water per year, saving an equal amount of drinking water for the region.
2021 West Basin Board of Directors approves the District’s 2020 Urban Water Management Plan (UWMP), a strategic water resources planning guide that demonstrates West Basin’s ability to provide reliable water supplies to the region for the next 25 years.
2021-Present California declares a statewide drought emergency.

  • A Level Three water shortage is declared on November 22, 2021, based on its 2021 Water Shortage Contingency Plan (WSCP), calling for voluntary water use reduction of 15%.
2021 West Basin Director Gloria D. Gray begins second two-year term as chairwoman of the Metropolitan Board of Directors.
2022 State Water Resources Control Board declares an emergency regulation to promote water conservation.
2022 Recycled Water Master Plan is finalized to help the District plan for the next chapter of its successful recycled water program.

  • New customers, project sites, and partnerships will be evaluated to ensure that West Basin continues meeting regional water demand with a sustainable, cost-effective water supply.
2022 West Basin celebrates the 75th anniversary of its formation and the following achievements:

  • Invested more than $750 million in its recycled water program;
  • Served nearly 250 billion gallons of recycled water; and
  • Distributed more than 330,000 water saving devices through conservation programs.

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