Tappan Lake is within the Lower Tuscarawas section of the Muskingum Area. It was authorized by Section 4 of the Flood Control Act (FCA) of 1938, as amended by Section 4 of the FCA of 1939. Primary project purposes are flood damage reduction, recreation, and fish and wildlife. The dam was completed in October 1936 and serves a drainage area of 71 square miles. Land includes 91 fee acres and 7,983 easement acres.