Fish Habitat Analysis for the Dungeness River Using the Instream Flow Incremental Methodology

摘要

An instream flow study of discharges required for fish use was performed by the Western Washington Fishery Resource Office, U.S. Fish and Wildlife (FWS), Olympia, Washington, and cooperating agencies of Washington State during 1988 and 1989, in the lower Dungeness River, Washington. We performed the study as part of a comprehesive effort to restore degraded runs of anadromous fish, particularly spring chinook and pink salmon. We used the FWS Instream Flow Incremental Methodology (IFIM) a and associated software to develop predictions per 1000 ft of stream for study sites located at river miles (RM) 2.3. and 4.2. The two study sites were selected to represent instream habitat found in river reaches from RM 1.8 to 2.5 and 3.3 to 6.4, respectively. Upstream of the represented reaches are five pints of irrigation withdrawal that remove varying amounts of water throughout the year. The principal objective of the study was to determine discharge vs. anadromous salmonid habitat relationsips for the lower Dungeness River. Using the IFG4 program to create hydraulic models from data collected at the study sites, we developed 10 models for the upper site and four models for the lower site.