The Need for Sites

California continues to face severe water challenges: limited supplies and a growing population, compounded by climate change, persistent drought conditions, and increased flow requirements for native fish. Now more than ever, California’s water system needs a more flexible, environmentally friendly solution to capturing and storing water for use when it’s needed most.

Sites is an innovative project and a 21st century solution to California’s water crisis. It is different than any other storage project.

Sites provides previously unachievable flexibility to the state’s water system without impacting sensitive river channels and critical environmental flows that support endangered fish populations.

Sites Works: It achieves California’s co-equal goals of water supply reliability and ecosystem improvement.

Sites has been studied for more than 30 years, and has statewide support. It is designed to give water agencies across the state more flexibility to meet both customer demands and environmental needs, especially in dry and critical years. Increased water supplies to farms and cities across California will have an enormous economic impact.

Sites Project

Adding 500,000 acre-feet to California’s water system – enough to serve 3.7 million people for one year.

Protecting thousands of regional and statewide jobs.

Up to half of Sites’ annual water supplies can be dedicated to environmental flows.

The benefits of Sites would outweigh the costs by a wide margin.

The benefits of the Sites project are expected to exceed costs by $61 million to $72 million annually, by leveraging support and financing of local and statewide water agencies that have already demonstrated significant commitment to the project.

Sites Benefits

  • Reliable water for California homes, businesses and farms
  • Environmental flows for native fish
  • Improved water quality
  • Contribute to California's renewable energy goals
  • Groundwater recharge
  • Flood management
  • Pacific Flyway habitat for migratory birds and other native species
  • Recreational opportunities

The Sites Region

The Sites project would be situated on the west side of the Sacramento Valley, approximately 10 miles west of the rural town of Maxwell, in historic Colusa County. The Sacramento Valley is a unique region, known for it’s farming community, rich agricultural benefits, and natural beauty. The region has been considered ideal for off-stream water storage since the 1980’s, a proposal that is widely supported by local community leaders, residents, as well as state water managers and agencies from the Bay Area to Southern California.


Recent News

Video Recap of October 21st Milestones Event

Oct. 25, 2016

Video from the October 21, 2016 press event at the new Sites Project office in Maxwell featuring several local elected officials, Sites Project Authority Board Members, and the president of the State Building and Construction Trades Council. ...


Sites Project Marks Significant Milestones, Gains Momentum

Oct. 21, 2016

Today, a diverse and bi-partisan group of state and local elected officials, regional water managers, agriculture, labor and business joined to mark the significant milestones achieved in the development of Sites Reservoir, and to acknowledge the momentum gaining for this important water storage project. ...


Rulemaking: Water Storage Investment Program Quantification Regulations

Aug. 29, 2016

The California Water Commission has proposed regulations for the quantification and management of the public benefits of water storage projects in accordance with the requirements of Proposition 1 ...


Water 101

The water that Californians use for drinking, recreating and protecting the environment moves through a system that is arguably the most complex in the world.

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Not only is there a maze of rivers and aquifers and channels and pipes and dams and tunnels…there is also an intricate system of laws and regulations that local, state and federal agencies deploy to protect and preserve this life-sustaining natural resource.

A complicating factor is that California is by-and-large an arid state. Much of our water comes in the form of snowmelt that originates high in the mountains of the Sierra Nevada and Shasta Cascade regions. But the highest demand for water is in the Bay Area and Southern California. Add climate change into the equation—meaning a shift from a snow-supplied system to a rainfall-capture system—and the careful balance becomes more tenuous.

California has two primary sources of water: surface water from rivers, lakes and streams; and groundwater from underground aquifers. There are others sources, including desalination and recycled water, which provide small amounts of water supply locally.

Groundwater has been managed on a local level historically. Implementation of the Sustainable Groundwater Management Act will bring cohesion and data to the groundwater system to help ensure long-term sustainability.

The state’s primary surface water system is comprised of the State Water Project and the federal Central Valley Project. Surface water is captured and stored in reservoirs and later released to meet water supply, flood control, water quality and environmental needs.

California’s primary source of water comes from the Sierra Nevada Mountains in the form of spring runoff, and is delivered through a complicated system of rivers, canals, and dams that work in conjunction to supply the state’s cities, towns, and farms. Our water system is an engineering feat that has fed a growing and thriving economy. But, climate change has resulted in conditions that our current system is incapable of handling – less snow, shorter, more intense storms, and increased salinity due to sea level rise.

Sites will help the state adapt to climate change by capturing and storing runoff supplies for use in dry and critical years. Between October 2015 and April 2016, over 1,000,000 acre-feet could have been diverted to Sites, filling 60% of its capacity in one year alone.

The project will also help recovering ecosystems by providing up to half of its annual water supplies to environmental flows, which will improve water quality for endangered fish, reduce salinity levels in the Sacramento-San Joaquin Delta (Delta), and improve Pacific Flyway habitat for migratory birds and other native species.

Sites would relieve stress on the state’s water system, allowing other reservoirs to hold more water later into the summer months. The added flexibility Sites offers would effectively increase the total storage in Northern California to more than 500,000 million acre-feet of water.

By creating a new source of water, and more flexibility in the system, Sites has the potential to help California succeed at implementing 21st century water solutions—to meet human AND environmental needs.

  • Groundwater sustainability requires effective groundwater recharge. Sites can help store and then move water where and when it’s needed for recharge projects.
  • Salmon need cold water to survive in the late summer and fall. If water for ag and Delta water quality came from Sites, cold water pools in Shasta and Oroville could be preserved.
  • If Sites had been in place in 2016, about 500,000 acre-feet could have been captured and stored—a much-needed boost to overall state water supplies in the middle of our historic drought.
  • Climate change is creating a new normal: less snow-pack and flashier rainfall. Sites is ideally located to maximize the capture and storage of rain.

Support For Sites

Below are just a few of the supporters of the Sites project


  • “Sites Reservoir will play a key role in making our state drought resilient by expanding our water reserves. The Sites project would help meet the water needs of our communities, farms, and environment. It has galvanized bipartisan support across California. The water bond, which provides significant funding for storage, was passed by an overwhelming majority of California voters. Let’s continue this momentum…and start building California’s water future.”

    Congressman Garamendi

  • “Sites provides more storage per dollar invested than any other proposed project, ensuring that California has water available for cities, farms and the environment during future droughts. It’s time to fulfill the promises made to voters, move forward on Sites, and build the infrastructure that will allow our state’s economy to continue growing for generations to come.”

    Congressman LaMalfa

  • “[Sites] would deliver benefits statewide by increasing water supply and, with proper management, providing versatility in water delivery for farms, cities and much-needed groundwater recharge. One of the most promising aspects of Sites is that a bloc of water would be allocated to the environment.”

    Editorial Board

  • “A reservoir like Sites in Colusa County would work. That lake would be in a basin west of Maxwell with no year-round streams. Instead, water would fill it through a canal when runoff on the Sacramento River is high in the winter and spring…That sort of "off-stream storage" makes the most sense when discussing new reservoirs.”

    Chico Enterprise-Record

  • “This bi-partisan effort promoting progressive water management is a step forward for California. The dry years in California have shown the importance of surface storage for all beneficial purposes--water needed for cities and rural communities, farms, fish, birds and recreation. An off-stream regulating reservoir on the west-side of the Sacramento Valley (Sites) is critical for all these beneficial purposes in the Sacramento Valley, as well as providing statewide water system operational improvements.”

    David Guy
    President of the Northern California Water Association

  • “The fact that Sites would not dam a river makes it more palatable to many than proposals to raise Shasta Dam on the upper Sacramento River and construct a new dam and reservoir on the San Joaquin River just upstream of the existing Friant Dam and Millerton Lake near Fresno.”

    Los Angeles Times

  • “Building Sites Reservoir is vital the Sacramento Valley. We need additional surface water storage to help all aspects of our region for future generations, including four annual salmon runs, habitat for millions of birds that depend on area rice fields, our small towns and family farms. ”

    Tim Johnson
    President & CEO, California Rice Commission

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