Building Local Supplies

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Think Regional, Act Local

Metropolitan’s role in the region has evolved over time. We are builders and planners. We brought water to Southern California, and we look today at the possibilities of local supply development to complement our imported supply investments. Our support of conservation and diverse local resource programs like water recycling, desalination, groundwater recovery and storage have provided over 7 million acre-feet to the region’s resource mix and increased our resiliency and reliability. Local resources are regional resources because they offset regional imported water demands.

It’s not an either-or situation: we’re developing local resources while shoring up our imported supplies. Each piece of our supply portfolio depends on the other. One is insurance against the other’s vulnerabilities. When imports are challenged by drought cycles or natural disasters, local resources and conservation programs can ease the burdens of import demands. In turn, high quality imported supplies are necessary for recycling and groundwater replenishment programs. Working together, these sources provide Southern California with reliable water. Having a mix of water resources to draw from has protected the region from the impact of drought cycles and climate change.


Local Supplies for Regional Reliability

When a local supply is developed, whether it is in Ventura, San Diego, or any community in between, all Southern California benefits. Our regional cooperation and interdependence mean one community’s recycling or groundwater cleanup project decreases the burden on Metropolitan’s system as a whole. That reduces operating costs, frees up conveyance capacity to benefit all system users and helps the region adapt to climate change. That is why Metropolitan supports and incentivizes several beneficial programs and initiatives that help the region act locally. We have invested $1.5 billion in these programs to date. For a rundown of achievements, click here and for the full Achievement Report click here.


The numbers tell a success story. In the 1990s, nearly 60 percent of Metropolitan’s supply portfolio was made up of imported resources from the Colorado River and our contract with the State Water Project. The balance was from local resources. A shift in the supply paradigm shows a 2035 mix of about 36 percent imported supply and 64 percent local resources.

Local Resources

Ensuring reliable water for Southern California requires investing in local water supplies from diverse sources and widespread conservation.

Future Supply Actions

Metropolitan is also investing in research to develop future local water supplies through innovative approaches. Through the Future Supply Actions Funding Program, Metropolitan funds member agency pilot projects and technical studies aimed at increasing the potential of recycled water, stormwater, groundwater and seawater desalination. Metropolitan has so far invested $6.5 million in more than two dozen studies.