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Surface Storage Investigations

In-Delta Storage
In-Delta Islands Map

This project has emphasized a new era approach by creating both new habitat on Holland Tract and Bouldin Island and new storage on Webb Tract and Bacon Island for flow-related ecosystem restoration actions, water quality, and improved water supply reliability for urban, agricultural, and environmental users in project designs.

In 2001, DWR, in coordination with California Bay-Delta Authority (CBDA) and with technical assistance from U.S. Bureau of Reclamation, began a joint planning study to evaluate the Delta Wetlands Project and other In-Delta storage options. This study, completed in May 2002, concluded that the project concepts proposed by Delta Wetlands were generally well planned. However, design modifications and further evaluations were needed before considering public ownership of the project. The study documents can be found here: (

In June 2002 the Bay-Delta Public Advisory Committee recommended that DWR complete additional evaluations and address several outstanding issues before considering implementation of the In-Delta Storage Project.

In January 2004 DWR, in coordination with CBDA and with technical assistance from U.S. Bureau of Reclamation, completed the In-Delta Storage Program State Feasibility Study that addresses the technical feasibility of the proposed In-Delta Storage Project. The Draft State Feasibility Study reports the findings of this additional work, and can be found here: ((

A Draft State Supplemental Feasibility Report was prepared in 2006 in response to comments recieved during the public review of the 2004 Draft In-Delta Storage Program State Feasibilty Study Report. The supplemental report describes new studies on a broad array of issues, including water supply and quality, project design, risk analysis, environmental evaluations,a nd construction costs.

The In-Delta Storage Project would provide capacity to store approximately 217,000 acre-feet of water in the south Delta for a wide array of water supply, water quality and ecosystem benefits. The project would include two storage islands (Webb Tract and Bacon Island) and two habitat islands (Holland Tract and Bouldin Island), similar to that proposed by Delta Wetlands over a decade ago, but would also include:

  • New embankment design
  • Consolidated inlet and outlet structures
  • New project operations
  • Revised Habitat Management Plans
Planning Objectives
  • Enhance water supply reliability and operational flexibility of the CVP/SWP system
  • Contribute to ecosystem restoration
  • Provide water for the EWA


DWR, in coordination with CBDA and with technical assistance from U.S. Bureau of Reclamation, completed the In-Delta Storage Program State Feasibility Study Report in 2004 and a Draft Supplemental Feasibility Report in 2006. The State feasibility study addresses engineering feasibility and risk, revised project operations that address drinking water quality concerns, project cost analyses, and potential project benefits and effects.

The In-Delta Storage Program has been suspended since July 2006 when State funding for the program was cut.



  • Reports and Presentations
  • Draft Supplemental Report to 2004 Draft State Feasibilty Study In-Delta Storage Project (1/2006)
  • State feasibility level evaluations to address outstanding issues
  • In-Delta Storage Program State Feasibility Study (1/2004)
  • In-Delta Storage Program Draft Work Plan for Fiscal Year 2003 (6/27/2002)
  • Reports for the CALFED Science Review Panel submitted (5/2002)
  • Released In-Delta Storage Program Draft Summary Report and supplemental reports on operations, water quality, engineering, environmental and economic evaluations for a 30-day public review (5/2002)
  • Completed pre-feasibility study (12/2001)

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