Water Affiliates Group

Join other water leaders to shape strategies to advance understanding of atmospheric rivers and droughts and improve water management, mitigate flood risk, and increase water supply reliability.

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CW3E leads science-based Atmospheric River and Forecast-Informed Reservoir Operations (FIRO) efforts to optimize weather, climate and water forecasts—providing water managers with tools to improve operations, increase water supplies, and promote public safety. Membership with the Water Affiliates Group is an opportunity to inform research strategies on operational tools to support core water management services.

CW3E Provides Actionable Information, Tools, and Technologies

Water Supply Reliability


Flood Management


GHG Mitigation

Decision Support

Groundwater recharge

Climate Outlooks: Months to Decades

Public safety

Hazard Assessment

Why Join the Water Affiliates Group?

  • Share your perspective with CW3E to tailor specific weather information for water managers for improved operations, increasing water supply while maintaining critical flood risk management
  • Connect with like-minded water leaders to share best practices in Forecast-Informed water operations

2024 Water Affiliates Group Member and Community Events

WAG Roundtable

Spring & Fall

Scripps Oceanography

All Water Affiliates Group Members

Founding Members

The City of San Diego Public Utilities Department is actively pursuing ways to increase water supplies and options. Collaborating with the Center for Western Weather and Water Extremes supports efforts to integrate the best available science and forecasting tools into water resource management and exemplifies the Department’s proactive approach to safeguarding reliable water supplies.

East Bay Municipal Utility District is committed to providing reliable, high-quality drinking water and wastewater service through sustainable activities that avoid, minimize or mitigate adverse effects to the environment and the public. Sustainability and resilience are essential principles that guide the actions of EBMUD in meeting the needs of customers.

Fresno Metropolitan Flood Control District provides to the citizens living within its boundaries, the ability to control and manage the flood, storm, and surface and groundwater resources of the area so as to prevent damage, injury, and inconvenience; to conserve such waters for local, domestic and agricultural use; and to maximize the public use and benefit of the District’s programs and infrastructure.

Irvine Ranch Water District (IRWD) is dedicated to providing, conserving, and maximizing the efficient use and reuse of water and renewable resources to benefit their customers and to enhance the environment. IRWD manages its supply and demand with careful research and analysis regarding flow, diversions, climate, customer demand and population estimates to ensure there will be an adequate supply of clean, reliable water.

Orange County Water District’s (OCWD) ability to reduce reliance on imported water depends on increasing capture of storm water released from Prado Dam. Current flood control manuals allow temporary capture of up to 20,000 acre-feet of water. With CW3E, advancing research observations for unique region-specific forecasts may permit Prado Dam to capture up to 30,000 acre-feet of water behind the dam and direct it to groundwater recharge.

San Bernardino Valley Municipal Water District (SBVMWD) has led the effort to enhance groundwater storage throughout the upper Santa Ana River Watershed.  As climate change influences the hydrologic cycle, water managers need to prepare for potentially extreme shifts in precipitation. By collaborating with CW3E, SBVMWD is preparing for maximum adaptation and resiliency in the face of unknown future conditions.  SBVMWD plans to collaborate with CW3E to assess both risks and opportunities for various groundwater recharge projects and incorporate Forecast-Informed Reservoir Operations (FIRO) modeling into water resource planning.

San Diego County Water Authority is working with CW3E to assess how better precipitation forecasts at a range of timescales can improve reservoir management in the San Diego region- maximizing local water supply and the reliability of water resources and improving the ability of water managers to make real-time decisions for managing limited water supplies.

San Francisco Public Utilities Commission (SFPUC) depends on accurate weather forecasts to optimize management of water resources by meeting competing objectives including maximizing water supply, ensuring dam safety, environmental stewardship, green hydropower production and recreation. CW3E models and data products provide critical information for the management of the SFPUC reservoirs and dams.

Salt River Project (SRP) was established in 1903 to coordinate the management of water supplies for shareholders of the Salt River Valley Water Users’ Association in Arizona. Over the past 100+ years, SRP’s expertise has grown into the conjunctive management of the 13,000-square-mile Salt River and Verde River watersheds that produce SRP’s surface water supplies; seven dams and reservoirs; more than 260 groundwater wells; three water-banking projects; and a vast electric generation, transmission and distribution system spanning multiple states to serve a 2,900-square-mile electric and 375-square-mile water service area in central Arizona. SRP strives to protect the water rights of its shareholder while also protecting the Salt and Verde river watersheds in a way that benefits all of those who depend on these rivers. This includes conducting research, working on watershed restoration efforts, and collaborating with water users and communities across the state.

Sonoma Water (SW) is responsible for wholesale water supply, flood risk management, and wastewater management. Because these operations are significantly impacted by ARs, SW has partnered with CW3E to assist in various applied research programs and other programs to help mitigating such impacts. Specifically, SW is partnering with CW3E on leading the implementation of FIRO at Lake Mendocino resulting in several major deviations being approved by the US Army Corps of Engineers to save up to 11,650 acre feet of water annually.

Turlock Irrigation District’s (TID) ability to protect against flood events depends on being able to more accurately forecast large rain events. In both 2017 and 2019, CW3E models gave TID time to create space in the reservoir through pre-flood releases to minimize the effects of storms forecasted to hit the area. In 2018, a dry year, the accuracy of CW3E models to forecast extreme weather events gave TID confidence to hold on to 150,000 acre-feet of water that would have been released otherwise.

Valley Water is committed to providing Silicon Valley safe, clean water for a healthy life, environment, and economy. Valley Water’s vision is to be nationally recognized as a leading water resources management agency.

Yuba Water Agency is dedicated to continuing to improve water supply management, especially reducing the risk of flood events. CW3E atmospheric river forecasting enhancements are being used to complement Yuba Water’s plans to build a $225 million secondary spillway at New Bullards Bar Dam, to provide early reservoir flood releases. The combination of new infrastructure and forecasting improvements is increasing public safety for the Yuba-Feather and surrounding regions.

Other Members

Marin County Department of Public Work consists of 20 divisions that work together to provide the community of unincorporated Marin with quality services, maintain and improve public infrastructures and facilities, and support the preservation of Marin’s unsurpassed beauty. The Flood Control Division is responsible for developing and maintaining a variety of flood reduction projects and working to address the impacts of climate change and sea level rise.

Marin Municipal Water District was chartered on April 25, 1912 and is the first municipal water district in California. Today, the District provides clean, reliable drinking water to more than 191,000 people in central and southern Marin. About 75 percent of the District’s water supply comes from its seven reservoirs located on Mt. Tamalpais and in west Marin, with the remaining supply coming from neighboring Sonoma County’s Russian River water system. Marin Water is interested in improved forecasting that will inform its water management decision making.

Modesto Irrigation District (MID) provides electric, irrigation and domestic water services for its customers, delivering the highest value at the lowest cost possible through teamwork, technology, innovation and commitment.

North Marin Water District (NMWD) is an independent special district that provides potable and recycled water to over 62,000 residents in the northern and western portions of Marin County. Approximately 20% of the NMWD water supply is provided locally through Stafford Lake, formed by Stafford Dam and the remaining supply is from Sonoma Water. The safety and benefits of Stafford Dam are of primary importance to NMWD and therefore understanding short and long term impacts as well as possible benefits from ARs is the key reason for the partnership with CW3E.

Santa Clarita Valley Water (SCV) provides responsible water stewardship to ensure the Santa Clarita Valley has reliable supplies of high quality water at a reasonable cost. We implement programs to ensure our service area’s supplies, which consist of both local groundwater and recycled water, and imported water from the State Water Project, other water contracts, and water banking programs, are sustainable. Furthering atmospheric weather forecasting, basin runoff forecasting, and understanding of western weather phenomenon can improve our ability to manage and optimize these resources.

Seattle Public Utilities (SPU) fosters healthy people, environment, and economy by partnering with our community to equitably manage water and waste resources for today and future generations. The utility provides reliable, safe, and high-quality drinking water to 1.5 million customers and plans, builds, operates, and maintains Seattle’s stormwater and wastewater systems. Weather forecasts, modeling, and technical expertise are used to manage our water resources efficiently, balance objectives for people and fish, plan and build resilient investments, and prepare for and respond to storm events. Partnering with CW3E will give us access to leading research, forecast tools, and insights on atmospheric rivers impacting our region that will help inform our operational decisions and improve our storm preparedness.

Water Replenishment District (WRD) is the largest groundwater agency in the state of California, managing and protecting local groundwater resources for over four million residents. WRD’s service area covers a 420-square-mile region of southern Los Angeles County, the most populated county in the United States. The 43 cities in the service area, including a portion of the City of Los Angeles, use about 250,000 acre-feet (82 billion gallons) of groundwater annually which accounts for approximately half of the region’s water supply. WRD ensures that a reliable supply of high-quality groundwater is available through the use of recycled water and stormwater capture. WRD is responsible for monitoring and testing groundwater throughout the region using effective management principles.

Annual Membership

Members receive tiered levels of access and visibility at CW3E Member and Community events with invitations to attend and present and quarterly newsletters. Membership support workshops and conferences for members as well as education, outreach, and innovation at CW3E. Membership is tax-deductible.

Platinum Level

  • 2 invitations to participate in WAG Roundtable Meeting hosted by Scripps
  • 2 invitations to Annual FIRO Workshop
  • 2 invitations to Executive Briefings
  • 2 invitations to select CW3E programming
  • 3 copies of Atmospheric Rivers by Ralph, Dettinger, Rutz, and Waliser ($300 value)

Gold Level

  • 1 invitation to Annual FIRO Workshop
  • 1 invitation to select CW3E programming
  • 2 copies of Atmospheric Rivers by Ralph, Dettinger, Rutz, and Waliser ($200 value)

Associates Level

  • Option to additionally sponsor WAG Member and Community Events a la carte
  • 1 copy of Atmospheric Rivers by Ralph, Dettinger, Rutz, and Waliser ($100 value)

F. Martin Ralph, Ph.D.

Vanessa Scott

Director, CW3E

Corporate Relations & Innovation



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