Economics of watershed planning / Edited by G.S. Tolley and F.E. Riggs. [Sponsored by the Southeast Land Tenure Research Committee, the Farm Foundation, and the Tennessee Valley Authority] Watershed planning. Symposium on the Economics of Watershed Planning, Knoxville ( 1959) Tolley, George S., 1925- Riggs, Fletcher Eugene. Watersheds. Water resources development. HD1691 .S9 1959 333.91 TOE Bibliographical footnotes. Ames : Iowa State University Press, c1961. c1961. 1961 Text ix, 339 p. : eng