Southern California is making one of the largest investments in water reuse infrastructure in the nation as agencies across the region work to reduce dependence on imported water supplies and strengthen long-term drought resilience.
A recent article published by Engineering News-Record explores the growing momentum behind potable reuse projects throughout Southern California, highlighting several major initiatives that aim to transform highly treated wastewater into safe, reliable drinking water supplies. The article also features multiple Carollo-supported projects advancing the region’s water future.
Potable Reuse is Becoming a Cornerstone of Water Supply Planning
The article describes how attitudes toward potable reuse have evolved dramatically over the past several decades. Projects that once faced significant public resistance are now gaining widespread support as communities confront increasing water scarcity, prolonged drought, and uncertainty about imported water supplies.
Los Angeles provides a clear example of this shift. The city currently imports approximately 70% of its water and is pursuing major investments in water recycling to reduce its reliance on imports. According to the article, water reuse is increasingly seen as a drought-resistant supply that offers greater reliability than traditional imported sources.
Major Water Reuse Projects Are Expanding Across the Region
Among the projects highlighted is the Los Angeles Groundwater Replenishment Project (LAGWR) at the Donald C. Tillman Water Reclamation Plant in Los Angeles, the largest active water project in California. At its core is a new Advanced Water Purification Facility (AWPF) that will produce up to 45 million gallons per day of highly treated water to help replenish regional drinking water supplies.
The article also examines Pure Water Los Angeles, a long-term initiative centered around the city’s Hyperion Water Reclamation Plant. The program seeks to significantly increase the amount of wastewater that is recycled and purified for beneficial use, supporting the city’s broader water independence goals.
In addition, the Metropolitan Water District of Southern California is advancing Pure Water Southern California, a program that could ultimately produce 150 million gallons per day of purified water while reducing reliance on imported Colorado River and Northern California supplies.
Together, these projects represent a regional strategy to diversify water supplies and build resilience against future drought conditions.
Collaborative Delivery is Accelerating Project Success
The article highlights how collaborative project delivery methods are helping utilities advance these complex programs more efficiently.
At the LAGWR, Carollo serves as the owner’s advisor, supporting project development alongside the Los Angeles Department of Water and Power, Los Angeles Sanitation and Environment, and design-builder Jacobs.
According to the article, the project team successfully expanded the AWPF’s planned capacity from 25 million gallons per day to 45 million gallons per day while construction was already underway. Through close collaboration and innovative construction approaches, the team was able to incorporate the larger treatment capacity without impacting the overall project schedule.
The article also highlights technical innovations developed during construction, including modifications to structural design and concrete placement strategies that improved constructability and accelerated delivery.
Building a More Resilient Water Future
As climate pressures continue to challenge traditional water supplies, Southern California’s growing portfolio of potable reuse projects demonstrates how advanced treatment technologies can create new, locally controlled water sources.
These investments are helping utilities reduce dependence on imported water, improve drought resilience, and strengthen long-term water reliability for millions of residents.
To learn more about the region’s ambitious water reuse initiatives and the projects helping shape Southern California’s water future, read the full Engineering News-Record article.
