The Grassland Ecological Area, lying in the heart of California's Central Valley, is a critical wintering area for numerous species of waterfowl and other migratory birds in the Pacific Flyway. It encompasses over 179,000 acres of wetlands and associated habitats, making it the largest block of contiguous wetland habitat remaining in California. Land ownership within the Grasslands Ecological Area is as diverse as the species who winter, breed and visit there. Private landowners maintain the majority of wetland habitat in the Grasslands with state and federal agencies providing stewardship over the rest.

Like virtually every other wetland within the Central Valley, the habitat values within the Grassland Ecological Area have been compromised by the needs of agriculture, the inevitable development pressures, inefficient and deteriorating water delivery systems, as well as a variety of other factors. However, unlike other wetlands, the Grasslands Ecological Area is the largest wetland complex in the state of California, making it a resource worthy of inspired collaboration and public investment.

The Grassland Ecological Area Enhancement and Restoration Project restored over 2,000 acres of seasonal and semi-permanent wetlands, 259 acres of associated uplands, and over 300 acres of riparian habitat, while enhancing 56,620 acres of existing wetlands, 1,527 acres of existing uplands, and 23 acres of existing riparian habitat. Restoration projects consisted of restoring natural functions to habitats that had been badly degraded or destroyed.  Vegetation was restored on uplands and riparian areas by planting or seeding degraded habitats and ensuring that long-term management objectives would maintain these habitats.

As most of the wetlands in the Grasslands consist of managed wetlands, they require efficient water conveyance systems to properly flood and maintain wetland habitat. These wetlands consist of leveed impoundments that use water control structures to convey water. Enhancement projects consisted of replacing or installing concrete water control structures that allow wetland managers to maintain optimal water elevations for waterfowl use, and excavating wetland swales that optimize flooding efficiency while diversifying the habitat. These swales also GEAprovide the ability to drain wetlands in order to promote germination of annual plants desired by feeding waterfowl.