Project Update: Sherman Island

Ducks Unlimited recently partnered with the California Department of Water Resources (DWR) to complete the third subsidence reversal project of Sherman Island in the San Joaquin-Sacramento Delta. These particular subsidence reversal projects work to sequester atmospheric carbon and raise soils elevations for an area plagued by land sinking.

Additionally, semi-permanent wetlands like those located at Sherman Island function as brood ponds for local nesting waterfowl. Within the last few years DU and DWR have completed 1,700 acres (2.65 square miles) between Sherman and the neighboring Twitchell Island. Ducks Unlimited recently received a grant from the Delta Conservancy and in partnership with DWR and CDFW are currently in the planning phase to design and permit an additional 2,900 acres (4.5 square miles) on the island.

Sherman Island was once a freshwater tidal wetland located in California’s Sacramento−San Joaquin Delta, which nurtures the drinking water supply for millions of Californians. Much of the land was diked off in the late 1800’s for farming purposes, and through oxidation, fires, and wind erosion has sunk to more than 19-feet below sea level, requiring large levees to keep delta islands from flooding. This project will have a net reduction of water diversion when compared to the previous irrigation agricultural practices, resulting in increased waterfowl breeding and loafing habitat and reduced demand on fresh water flows.