ABSTRACT.The study was prepared in 1966 for the Bureau of Sport Fisheries and Wildlife, Department of the Interior, for presentation to the United States Army Corps of Engineers which had under study several routes for rediversion of the discharge from the Santee‐Cooper Hydro Electric Plant, Steam Plant and Lock. Each rediversion was designed to by‐pass the Charleston Harbor and this study and report was concerned with one of those routes–Rediversion Route “B.” The channel was to be designed for a maximum fresh‐water flow of 27,500 cfs and a mean flow of 15,500 cfs. The objectives of the study and report were to make an estimate of: (1) the geographical extent of salt marsh waters of which the salinity will be measurably reduced, and (2) the probable accumulation of fresh‐water borne sediments in those same waters. Special consultants were Dr. F. H. Kellogg, Memphis State University, and Mr. K. L. Drennan, Gulf Coast Research Laboratory