The 2-Gates Project proposes an alternative management strategy to achieve protection of the delta smelt (Hypomesus transpacificus). The Central Valley Project (CVP) and State Water Project

(SWP) operate under the OCAP and other water rights and water quality requirements (project background provided in Appendix A). These operations comply with the RPAs in the recent BOs for the OCAP from the U.S. Fish and Wildlife Service (FWS 2008) and National Marine Fisheries Service (NMFS 2009). The RPAs include actions to limit reverse flows in Old and Middle Rivers to reduce entrainment of fish at the CVP and SWP export facilities.

The Project seeks to provide equal or improved protection to delta smelt (reduced entrainment at the export pumps) with higher than the minimum allowed water exports described in the OCAP BORPAs while operating within the other water management requirement (D-1641). In particular, the Project is intended to demonstrate that operable barriers, strategically placed in the central Delta and managed in conjunction with some restrictions on OMR negative flows, can provide equal or greater protection for delta smelt than restrictions on OMR negative flows alone. The proposed 2-Gates Project is designed as a demonstration project to test this premise and to improve understanding of the key physical and biological processes needed to restore a sustainable ecosystem.

The 2-Gates Project proposes to install and operate temporary, removable gates in two channels in the central Delta at Old River and Connection Slough (Figure 1). The gates will be used to manipulate flows and key water quality components of delta smelt habitat in order to reduce entrainment of delta smelt at the export facilities.