April 2014

The historic wetlands of California’s Central Valley once supported millions of migratory bird species along the Pacific Flyway. With significant loss of these natural historic wetlands, the managed wetlands of California’s wildlife refuges now support some of the largest concentrations of wintering waterfowl. However, due to rising water costs and competing demand, these refuges have not received their legislatively-mandated deliveries of water as specified in the Central Valley Project Improvement Act (CVPIA) of 1992 and increasing water scarcity further increases uncertainty in future water supply. Through application of the California Value Integrated Network (CALVIN) model, an economic-optimization model of California’s water supply system developed by researchers at the UC Davis Center for Watershed Sciences, this research aimed to understand potential water supply portfolios of Central Valley’s wildlife refuges in the face of climate change and major water infrastructure developments such as the Bay Delta Conservation Plan (BDCP). This work is conducted in collaboration with the U.S. Fish and Wildlife Service.

Graphic: Flooded wetland habitat at Merced National Wildlife Refuge (Merced County).