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Review of Draft Plan for Adaptive Management of Fall Outflow for Delta Smelt Protection and Water Supply Reliability

Review Panel Summary Report



The US Fish and Wildlife Service (Service) issued a Biological Opinion (BiOp) on the Central Valley Project (CVP)/State Water Project (SWP) operations in 2008 that concluded that aspects of those operations jeopardize the continued existence of delta smelt (DS). The Reasonable and Prudent Alternative (RPA) that was issued with the BiOp calls for implementation of adaptive management of Fall Delta out flow in above normal and wet years. The Fall outflow action is expected to improve habitat suitability and contribute to higher average DS abundances. The RPA calls for Delta out flow to be managed such that Fall X2 (the location of the 2 ppt isohaline) must average either 74 km or 81 km upstream from the Golden Gate during the month of September and October, respectively, if the water year containing the preceding spring was classified as wet or above normal. 2011 is classified as a wet year invoking the expectation of X2 at 74km. The RPA requires that adaptive management (AM) be used to assess the effectiveness of the action, including a feedback loop allowing the action to be re fined in future years from learned information with the objective of improving outcomes. In 2010, the US Bureau of Reclamation (Reclamation) led a planning initiative to develop an adaptive management plan for Fall out flow, but external review suggested that greater bene fits to understanding the consequences of the X2 location could be obtained from an active (or experiment driven) AM approach rather than the passive approach proposed. The AM Plan was revised in 2011 to address these concerns and Reclamation and the Service requested an independent Science Review at the early stages of the plan revision. This Review Panel (Panel) was convened by the Delta Science Program in June 2011 and the present document serves as a review of the Panel’s findings and recommendations. The Panel appreciated the opportunity for involvement in the early formative stages of the plan and developed the review in less than 3 weeks to allow recommendations to be fully considered during the final planning for the 2011 Fall outflow.


Review Panel Members:

Denise Reed, University of New Orleans

Ernst B. Peebles, University of South Florida

Peter Goodwin, University of Idaho

William V. Sobczak, College of the Holy Cross

Hans W. Paerl, University of North Carolina - Chapel Hill

Eric B. (Rick) Taylor, University of British Columbia

Coequal goals

The Delta Stewardship Council was created in legislation to achieve the state mandated coequal goals for the Delta. "'Coequal goals' means the two goals of providing a more reliable water supply for California and protecting, restoring, and enhancing the Delta ecosystem. The coequal goals shall be achieved in a manner that protects and enhances the unique cultural, recreational, natural resource, and agricultural values of the Delta as an evolving place." (CA Water Code §85054)