Middle Fork American River near American River Pump Station
RiverArc Project logo
A Spawning Steelhead Salmon


The proposed RiverArc Project will benefit our region in many ways. The primary benefits include:

  • Reduce our region's reliance on Folsom Lake and Lower American River

  • Enhance groundwater sustainability through coordinated use of groundwater and surface water

  • Support goals of the Sustainable Groundwater Management Act

  • Protect Northern California's rivers and watersheds

  • Improve our environment and support native species with colder water temperatures

  • Replenish poor quality groundwater with treated Sacramento River water

  • Enhance options for state and federal water managers to operate the statewide water system based on changes in water temperature, quality, and demand

  • Benefit the environment and Delta water quality

  • Increase cold-water pools in Folsom to better manage flow temperatures in the Lower American River

  • Bring surface water to communities with few options

  • Support economic vitality

  • Sustain our local economy

  • Offset demands from the Lower American and Folsom Lake during dry years

Using Natural Infrastructure to Store our Water

To protect against prolonged droughts, the Sacramento region can more efficiently use the natural storage that our groundwater basins offer. RiverArc allows for maximizing the surface water-groundwater connection by facilitating the use of more surface water in wet years, thereby providing in-lieu groundwater recharge (i.e., build-up of stored groundwater) for use in dry years.

Modeling efforts confirm that RiverArc benefits Folsom and the Lower American River in most years. By shifting diversions from the American River/Folsom Reservoir to the Sacramento River, flows in the Lower American River would be increased by up to 43 thousand acre feet (TAF) annually.

Folsom Reservoir storage could increase by up to 15 TAF, with the greatest increase occurring during drier years. These flow and storage increases would provide Reclamation with the flexibility to increase system-wide Central Valley Project water supply, enhance Lower American River flows for fish habitat and spawning, and/or improve temperature management on both the American and Sacramento rivers.

RiverArc was evaluated as part of the American River Basin Study, a climate change study led by the U.S. Bureau of Reclamation. The study showed RiverArc will generate positive regional and system-wide benefits.

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