Department of Water Resources Home

Surface Storage Investigations


Jim Wieking,
Project Manager

Dept of Water Resources
901 P St., Room 213 A
Sacramento, CA 95814
Phone: (916) 651-9279


Ted Thomas,
Public Information Officer

Dept of Water Resources
1416 9th St, Room 252-20
Sacramento, CA 95814
Phone: (916) 653-9712

North-of-the-Delta Offstream Storage Investigation

FAQs: The Drought and Sites Reservoir                FAQ: Sites Reservoir Diversion

2014 NODOS Documents

Proposed Sites Reservoir



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.