Water Supply


Most of Petaluma’s water is imported from the Russian River system, supplied by Sonoma Water. To supplement the imported water supply during water shortage periods and during peak summer demands, Petaluma utilizes local municipal groundwater wells. To learn more about Sonoma Water’s water supply and current conditions, click here.

To conserve water and reduce current and future demands for potable water, the City provides recycled water to irrigate urban parks, schools, and public and private landscapes that historically used drinking water for irrigation. Additionally, the City has a robust water conservation program to help our residents and commercial customers conserve water. Click here to learn more.

As shown in this graph, the population (red line) has increased over time while citywide water use has decreased. Improved indoor and outdoor water use efficiency has allowed us to serve more people with less water than we have historically. To ensure this is the case for many years to come, and under varying water supply conditions, the City is working to expand our local water supplies which you will learn about below.


Cup of water under faucet

Intergrated Water Master Plan

To enhance our community’s water supply resiliency, Petaluma is embarking on a study called the Integrated Water Master Plan (IWMP). This plan will identify opportunities to increase water supplies locally, making us more resilient to water supply shortages due to climate change and other natural disasters such as earthquakes. Learn more here.

Urban Water Management Plan

In compliance with the California Water Code, the City updates and adopts its Urban Water Management Plan (UWMP) and submits it to the Department of Water Resources every 5 years. The UWMP looks at water supply and demand over a 20-year planning horizon, and provides information about the City's water supply sources, current and projected population, historical and projected water use, and water supply projections for drought conditions.

As part of the UWMP, the City is required to prepare an updated Water Shortage Contingency Plan (Shortage Plan) every five years. The Shortage Plan defines water shortage levels and identifies corresponding actions the City implements to reduce demand under mild to severe water shortage conditions.

The City's 2020 UWMP was adopted by City Council on June 21, 2021.

The City’s Amended 2020 Shortage Plan was adopted by City Council on August 1, 2022.

Amended 2020 Water Shortage Contingency Plan

2020 Urban Water Management Plan

2020 Urban Water Management Plan Appendices A-N

2015 Urban Water Management Plan

Petaluma's Water Supply History

The City of Petaluma’s water system originated in the late 1800s, to meet the growing demand as development occurred in the downtown area. The City’s original water source was the headwaters of Adobe Creek. In 1910, the City constructed Lawler Reservoir in the hills east of Petaluma to boost water supply. In 1937, stream diversion facilities and a water treatment plant were constructed at Lawler Reservoir to supplement surface water supply.

In 1960, the City of Petaluma entered into an agreement with the Sonoma County Water Agency for the annual delivery of 4,500 acre-feet of water. In December 1961, the Sonoma County Water Agency completed the Petaluma Aqueduct and the City of Petaluma began taking delivery of water, along with the North Marin Water District, from the Sonoma County Water Agency’s Russian River Water System. The City decommissioned Lawler Reservoir in the early 1990s.

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