Interagency Approach to Watershed Problems of Eel River

The watershed management-oriented studies made in the basin are summarized and overall conclusions drawn. The U.S. Geological Survey estimated the long-term average suspended sediment load near the mouth at 7,400 tons per sq mile of drainage area. Among larger rivers of the world, this figure is known to be exceeded only by the Yellow River of China and certain of its tributaries, and the Semani River in Albania. The U.S. Soil Conservation Service found that the principal sediment sources in the basin were streambank erosion (64%) landslides (26%), and sheet and gully erosion (10%). The maximum feasible sediment reduction through land treatment measures was estimated at about 20%. Active and intensive watershed management can be expected in the future in problem areas in the Eel River Basin as measures such as cover manipulation become economically feasible and more is learned about wildland water quality and quantity control.