Clean, Local and Sustainable
The Future of L.A.’s Water Supply is Taking Shape in the San Fernando Valley
In the early 1900’s William Mulholland, the first superintendent and chief engineer of the new Municipal Water Department found himself preoccupied with the exponential growth and water needs of the City of Los Angeles. As a man of vision, Mulholland met this challenge with the construction of L.A. Aqueduct in 1913. Today, much like at the turn of the century, the City of Los Angeles collectively finds itself pondering the nature of its water resources.
Once again, the city is in a situation where it must find innovative ways of developing reliable water supplies for the 4 million residents in Los Angeles. The continued unpredictability of our climate from one extreme to the next, coupled with a costlier, dwindling, seismically vulnerable and increasingly coveted supply of imported water has brought us to a crossroads. Thankfully the determined staff at the Los Angeles Department of Water and Power (LADWP), along with other partner agencies have dedicated a great portion of their careers to tackling this important problem.
The Solution
The solution to this complex problem requires that we look inward and work with the resources that we have on hand, instead of being beholden to factors outside of our control. It requires thinking locally and long-term with a carefully thought-out plan that considers existing and innovative technology while continuing to provide reliable water service to our customers. Enter the Los Angeles Groundwater Replenishment Project (LAGWR), one of the largest potable reuse water projects in the state and a collaboration between LADWP, and the L.A. Bureau of Sanitation and Environment (LASAN).
LAGWR will create a new, local, drought resistant source of purified water; up to 45-million gallons of water per day (MGD) – enough to meet the drinking water needs of 500,000 customers. The LAGWR broke ground in December 2024 at a site next to LASAN’s Donald C. Tillman Water Reclamation Plant located in the San Fernando Valley. As a blueprint for future projects and initiatives, the LAGWR will create a sustainable source of local drinking water for the City of Los Angeles. The project will achieve two main strategic goals by helping LADWP produce safe, high-quality drinking water, and it will develop a locally controlled and sustainable water supply for the City of L.A.
LADWP has experience with recycled water for 50 years and it is a key component of LADWP’s goals outlined in the 2025 Urban Water Management Plan, the Los Angeles New Deal, and the Mayor’s Executive Directive 5. LADWP is investing $930 million on the LAGWR Project – and what is even more impressive is that LADWP has received over $400M of external funding from federal, state and local partners. This major investment demonstrates LADWP’s commitment to confronting the challenges brought on by climate change, and the LAGWR Project will develop a new cost-effective water supply for the city.
Treatment at a Glance
LAGWR will create a new, local, and drought-resistant water supply by utilizing wastewater from the Valley, which will then be treated at the Tillman Water Reclamation Plant. The next step is purification to a higher water quality standard at the Advanced Water Purification Facility using industry proven technology that is used throughout the world known as Full Advanced Treatment. This new purified supply will have the added benefit of recharging the Hansen Spreading Grounds and replenishing the local groundwater in the San Fernando Basin.
The recharging of the groundwater basin adds to our local water bank and improves groundwater quality. LAGWR is a transformational investment in climate resilience, environmental stewardship, and provides another layer of water security for LADWP customers.
Los Angeles Groundwater Replenishment Project Highlights
45 MGD (million gallons per day)
22,000-acre feet of recycled water by 2027 and expected to grow to 40,000 AFY (1 acre foot = 325,851.43 gallons)
Water for 500,000 customers
$930M total project cost with 40 percent funding through external sources reducing impact on ratepayers
Diversification of our local water supply
Integrates environmental stewardship by maintaining the health and habitat of the L.A. River
1,500 local jobs during construction
New state-of-the-art education center
2023 Excellence in Engineering and Science: Grand Prize in Planning
2025 Excellence in Engineering and Science: Grand Prize for Environmental Sustainability
Future Milestones
LADWP is focused on the completion of the LAGWR Project by 2027, and a large team of dedicated staff is working diligently to bring this project online prior to the 2028 Olympics. In addition to creating a new, sustainable water resource and recharging our underground aquifers, the LAGWR will also provide economic and community benefits to the Los Angeles region. Up to 1,500 jobs are involved during the construction resulting in a boost to the local economy and the creation of new jobs.
Final commissioning and operation are expected by early 2028, just in time for the L.A. Summer Olympics. Combined with several other projects and initiatives, the City of Los Angeles will be able to welcome the world while highlighting new infrastructure designed to enhance livability, sustainability, and quality of life.
For more information about the Groundwater Replenishment Program, please visit ladwp.com/GWR.