A summary of the results of applied research on salinity control of irrigation return flows in the Grand Valley of Colorado is presented for the period of 1969 to 1976. Salinity and economic impacts are described for the Grand Valley Salinity Control Demonstration Project which contains approximately 1,600 hectares and involves most of the local irrigation companies in the Valley. During the eight years of the demonstration project, 12.2 km of canals were lined, 26.54 km of laterals were lined, 16,400 meters of drainage tile were installed, a wide variety of on-farm improvements were constructed, and an irrigation scheduling program was implemented. On-farm improvements evaluated were solid-set sprinklers, side-roll sprinklers, drip (trickle) irrigation, furrow irrigation, and automatic cut-back furrow irrigation. The total value of the constructed improvements in the demonstration area was about $750,000. The total improvements resulted in a salt reduction of 12,300 metric tons per year reaching the Colorado River. This salt reduction results in an annual benefit to downstream water users of nearly $2,000,000. In addition, there are benefits to the local water users with increased crop yields, and to the people of Grand Valley in increased business.

"EPA-600/2-78-160"--Cover. "July 1978"--Cover. "Agricultural and Chemical Engineering Department Colorado State University"--T.p. "Project Officer James P. Law, Jr. Source Management Branch Robert S. Kerr Environmental Research Laboratory"--T.p. "Submitted in fulfillment of grant no. S-802985 by the Agricultural and Chemical Engineering Department of Colorado State University."--Page v. Sponsored by the Robert S. Kerr Environmental Research Laboratory, U.S. Environmental Protection Agency Bibliography: p. 188-192.