Restoring Coastal Wetlands: The Californian Experience

Abstract

ABSTRACTCoastal wetlands are an important natural resource, providing habitat for fish and wildlife, particularly many rare or endangered species. These wetlands also serve important functions for the treatment of urban runoff and effluent discharges, the dissipation of wave energy, and shore protection. The US Fish and Wildlife Service estimates that approximately 45 000 km2 of US wetlands have been destroyed in the past two centuries.The importance of wetlands in the ecosystem has only begun to be understood during the past two decades, and there has been a major legislative effort to preserve, protect, and enhance existing coastal wetlands. The productivity of tidal wetlands is related directly to the hydrologic characteristics of the system, and some considerations for the hydrologic design for the enhancement or construction of tidal wetlands are outlined. Recent attention has focused on the use of dredged spoil materials from harbours or shippping channels to restore historic tidal wetlands. The hydrologic design criteria are illustrated through a series of case studies in California.