Pursuant to the Endangered Species Act, in October 2019 the United States Fish and Wildlife Service (USFWS) of the Trump Administration issued a new Biological Opinion (BiOp) for coordinated operations of the Central Valley Project and the State Water Project (2019 USFWS BiOp).
The Central Valley Project is operated by the United States Bureau of Reclamation (Reclamation), and the State Water Project is operated by the California Department of Water Resources. The Central Valley Project and the State Water Project both divert freshwater from the Sacramento River and San Joaquin River watersheds, and the reduced freshwater flow resulting from these diversions allows in additional ocean water, raising salinity levels.
The 2019 USFWS BiOp issued by the Trump Administration found that anticipated water project operations would not jeopardize the survival of the endangered delta smelt, a fish species dependent on low-salinity conditions and found only in the brackish estuary where the freshwater of the Sacramento and San Joaquin Rivers mix with the seawater of the San Francisco Bay. The “no jeopardy” determination in the 2019 USFWS BiOp contrasted with the previous 2008 USFWS BiOp, which found that anticipated water project operations would likely push the endangered delta smelt into extinction due to elevated salinity levels.
47 Ecology Law Currents 209 (2020).