You are here

Independent Review Panel (IRP) Report of the Collaborative Adaptive Management Team (CAMT) Proposed Investigations on Understanding Population Effects and Factors that Affect Entrainment of Delta Smelt at State Water Project and Central Valley Project

Review Panel Report - December 19, 2014



The Independent Review Panel (IRP) reviewed the proposed “Investigations on Understanding Population Effects and Factors that Affect Entrainment of Delta Smelt at State Water Project and Central Valley Project.” The investigations were partitioned into four independent but linked proposals concerning factors affecting entrainment and population consequences of entrainment. The goal of the investigations is to support a more confident assessment of Delta Smelt entrainment and, stemming from that greater understanding, to assess the efficacy of management actions used to operate the water projects in a manner consistent with the ESA. The investigations are to be directed at adult stages of Delta Smelt with the understanding that studies of larval and juvenile stages would be developed later. The IRP was charged with responding to 10 questions. Each proposal was reviewed independently and then the proposals were considered as an integrated study. In general, the IRP believes the investigations will increase the understanding of processes controlling Delta Smelt entrainment and strongly supports the collaborative and integrated nature of the project. The investigations are linked in which Proposal I studies factors of entrainment at Delta-wide scale, Proposal II studies factors at the fish centric scale, Proposal III uses results from I and II to expand salvage sampling to entrainment estimates and Proposal IV studies the effects of entrainment on the Delta Smelt population. Proposals I, III and IV essentially revisit previous analysis using recent data sets. Proposal II is new in that it will model detailed movement of Delta Smelts based on how hydrodynamics and turbidity fields interact with fish behavior. The proposals are ambitious and the degree of success of the outcome in providing useful information for management is uncertain given the limitations of data, the lack of definition in movement models and project scheduling. The goal of the IRP is to illuminate critical weaknesses and in places suggests alternative perspectives that may strengthen the project.

The review was held on November 14, 2014 in Sacramento, CA.


Review Panel Members:

Dr. James J. Anderson, (Lead Author), University of Washington

Dr. James H. Cowan, Louisiana State University

Dr. Nancy E. Monsen, Stanford University (Visiting scholar, independent engineering consultant)

Dr. Don L. Stevens, Jr., (Panel Chair), Oregon State University (Retired)

Dr. Scott Wright, U.S. Geological Survey

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)