Orange County Water Reliability Study

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The Orange County Water Reliability Study (The Study) is a comprehensive study of Orange County’s long-term water reliability, providing valuable information to key decision makers regarding the future of Orange County’s water supplies. “Being Reliable” refers to having sufficient water to avoid shortages whether from droughts, earthquakes or other emergencies, as well as having the ability to meet current and future water demands.

Southern California’s water reliability is tied to the success of The Metropolitan Water District of Southern California’s (MWD) Integrated Water Resources Plan (IWRP) which calls for investments in both imported water, and the development of new local water supplies. The Study, completed in 2016, and updated again in 2018 to include the projected completion of the California WaterFix, has been developed to present unbiased, factual information to Orange County water industry staff and elected officials. The information prepared will aide in the decision-making process about how to approach and manage current and expected water supply issues out to the year 2050.

From Indirect Potable Reuse (IPR), water recycling or ‘purple pipe’, to saltwater desalination, Orange County explores and utilizes a robust portfolio of water supplies. However, without any new investments in southern California water, either imported or local, The Study shows with a growing population, Orange County will face regular water shortages.

The Study determined that with limited groundwater, to achieve reliability South Orange County needs additional investments in water supply, while North Orange County has sufficient local resources to manage through potential shortages.

The Study will assist MWDOC in its role of advocating policy issues at MWD regarding regional projects, water rates, MWD’s Local Resources Program (LRP) funding, MWD’s Water Supply Allocation Plan (WSAP) issues, MWD’s groundwater replenishment efforts, and MWD’s efforts to provide regional emergency storage.

2023 OC Reliability Study Final
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2018 OC Reliability Study Final
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2016 OC Reliability Study Executive Report
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MWD’s IWRP plan
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