Document Details

State Water Project Delivery Reliability Report 2013

California Department of Water Resources (DWR) | December 1st, 2014


This State Water Project Delivery Reliability Report 2013 updates the estimated water delivery capability of the State Water Project (SWP) for current conditions and two decades from now. The estimates include the best-known future effects of climate change and the anticipated changes in Sacramento River basin land uses. Climate change will alter the timing and magnitude of inflows to upstream storage facilities including Shasta, Folsom, and Oroville reservoirs. In addition, rising sea levels will pose operational challenges to maintaining suitable salinity levels in San Francisco Bay and the Sacramento–San Joaquin Delta (Delta).

Other factors in our analysis of SWP reliability have been assumed to not change over time. They are too uncertain to incorporate into the analysis. For example, regulatory restrictions issued by the U.S. Fish and Wildlife Service and the National Marine Fisheries Service in their biological opinions are assumed to remain unchanged. The opinions dictate the timing and amounts of the SWP’s Delta exports. These restrictions are undergoing further review and analysis under a federal court order. Also, the Delta water quality and flow requirements contained in the State Water Resources Control Board’s water quality control plan for the Delta are assumed to remain unchanged. However, the board is revising its water quality control plan. Revisions to the plan and their subsequent inclusion into the California Department of Water Resources’ (DWR’s) water rights for the SWP could have a significant effect on SWP deliveries.

The estimates in this report can be used by water districts as part of the analyses for their water management plans, which are required by State legislation to be updated in 2015. The report includes estimates for a range of hydrologic conditions that should be considered in water management plans. These estimates do not incorporate the risk of a disruption in SWP deliveries caused by catastrophic failure of Delta levees. Delta levee failure as a result of floods, earthquakes, erosion, or rising sea levels could interrupt water deliveries from the Delta for weeks, months, or even years, depending on the nature and the scope of the failure. Water management plans should describe the response to this potential scenario.

This assessment of current and future SWP reliability is one of several efforts by DWR to help plan for reliable future water supplies in California.

Keywords

State Water Project (SWP), water project operations