The California Department of Water Resources and the U.S. Bureau of Reclamation, working in cooperation with other federal, state, and local agencies, are studying the potential feasibility of alternative plans to build an offstream surface storage north of the Sacramento-San Joaquin Delta as part of the North-of-the-Delta Offstream Storage (NODOS) Investigation.

NODOS would provide a robust set of benefits, including water supply reliability for municipal and industrial uses, agriculture, and wildlife refuges; ecosystem enhancement actions to improve fish survival in major northern California rivers and the Sacramento-San Joaquin Delta (Delta); water quality improvements for Delta water users and estuarine species; flexible hydropower generation to support renewable energy sources such as wind and solar; recreation opportunities at the new reservoir and improved recreation at existing reservoirs; and local flood damage reduction below the new reservoir. Total water supply benefits of NODOS would be up to 500 thousand acre-feet (TAF) per year on average and over 600 TAF per year during dry and critical years.

The mix of NODOS benefits would also support improved flexibility and long-term viability of the Central Valley Project (CVP) and State Water Project (SWP). As the current drought is showing, flexibility of these projects is impaired during multiple dry years or droughts. In addition to providing the benefits described above, NODOS would improve CVP and SWP flexibility by increasing water in storage, including during drought conditions. Average annual improved storage would be up to 1.4 million acre-feet (MAF); annual drought period storage would be improved by up to 1.1 MAF.

The potential environmental effects of constructing and operating NODOS are evaluated and potential mitigation measures are described in the NODOS Preliminary Administrative Draft Environmental Impact Report.  The preliminary benefits and costs are presented in the NODOS Preliminary Design and Cost Estimate Report.


Sites Joint Powers Authority website:

USBR website:

DWR website:



Sites Reservoir Alternatives Evaluation – Memorandum November 2014

NODOS Highlights Booklet 28May14(1)