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.

Annual Water Production


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, like those we are experiencing now.

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. We are currently in Stage 4 of the Shortage Plan, designed to reduce our City’s water use by 30% through mandatory restrictions.

The City’s 2020 UWMP was adopted by City Council on June 7, 2021 and the Amended 2020 Shortage Plan was adopted by City Council on August 1, 2022.

2020 Urban Water Management Plan

2020 Urban Water Management Plan Appendices A-N

Amended 2020 Water Shortage Contingency Plan

FINAL 2015 Urban Water Management Plan


The below programs are in progress to help build the City’s water resiliency, added assurance that we have access to water. This is especially helpful in times of emergency like drought, earthquake, and fires.

Expand Municipal Groundwater Wells

Supply Expansion 
Expand Municipal Groundwater Wells - We are developing new wells throughout the city to take advantage of Petaluma’s existing groundwater supply. This will ensure that water is available throughout the city during times of emergency.

Recycled Water

Recycled Water
Recycled Water Program Expansion - We are expanding our urban recycled water pipeline to offset potable water use. We are also currently updating our Recycled Water Master Plan which will explore and identify all reuse options.

Groundwater Storage

Groundwater Storage
Aquifer Storage and Recovery (ASR) Plan - We are looking at the feasibility of taking surplus drinking water from the Russian River system during wet winter years and storing it in an underground aquifer in the Petaluma groundwater basin. The stored water would then be available as an emergency backup supply. This is also known as groundwater banking.



Building codes require indoor and outdoor water use efficiency. Permitted projects with landscaping must meet local and state water use efficiency requirements. During severe water shortages, the City may put in place regulations on new development.

Educational Videos

Check out the videos below from Sonoma Water which provide excellent background and context on the subject of the Russian River watershed, river flows, and the water supply system upon which we are so dependent.

The Russia River Story: Watershed Stream Flows Video

Sonoma Water – Water Supply System “How does water get to your home?”


To learn more about the City's water conservation programs, CLICK HERE.

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.

Whether it’s generational families expanding or new people joining our community, Petaluma is growing. With growth comes the need for additional housing.

To ensure there is enough housing for everyone to live affordably, the State of California determines projected population numbers and estimates the number of new housing units needed to meet demand. The State allocates each city a number of housing units that are required to be built to support the growing population.

The State also requires water suppliers to ensure there is enough water available for California communities. As a water supplier, the California Water Code requires Petaluma to prepare an Urban Water Management Plan (UWMP) every five years to assess the reliability and availability of water for current and future needs over a 25-year planning horizon. Water demand projections take into consideration several factors including population and employment growth, anticipated development in the General Plan, a range of dry year scenarios, and more.

The California Water Code also requires the City to prepare an updated Water Shortage Contingency Plan (Shortage Plan) every five years, which defines water shortage levels and identifies response actions that reduce water use to meet a reduced water supply.

While required by the State to create new housing units, Petaluma values sustainable growth that offers affordable and diverse housing for our community. Some ways we protect our finite water supply – both year-round and during water shortage emergencies – while continuing to develop the housing our community needs, is to create rules and guidelines for new development. Some of these rules and guidelines include:

  • Building codes that require indoor and outdoor water efficiency.
  • Municipal code requirements for new and rehabilitated landscapes to use water efficiently and maintain a water budget based on plant type and landscaped area.
  • New development is only allowed to plant between November 1 and April 30.
    • Exception for stormwater treatment features.
    • Exception for mitigation plantings required by regulatory agencies.

As shown in the graph on this webpage, 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, the City continues to expand its water supply portfolio and rules for new development so we are better prepared for future water shortages. Let’s make water conservation a way of life in Petaluma!

For water saving tips, resources, and programs, visit the City’s Water Conservation webpage – CLICK HERE.

Our water supplier, Sonoma Water, regularly reports on the latest water supply levels and provides context by comparing those levels to recent years. Click here to learn more.

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