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irrigation improvement measures. These improvements were expected to reduce irrigation drain flow to about 108,000 acre-feet per year. In addition, the Colorado River Basin States have established a salinity standard at Imperial Dam of 879 milligrams per liter (mg/L). Using a salt balance formula and assuming an irrigation drain flow of 108,000 acre-feet and salinity at Imperial Dam of 838 mg/L, a plant size of 73 million gallons per day would be required to treat the irrigation return flow portion of the total drainage flow. The plant was constructed to produce about 72.4 million gallons of desalinated (product) water per day when operated at full capacity. This would result in a delivery of about 68,500 acre-feet of product water per year. The product water will be blended with untreated drainage water to salvage an estimated 78,000 acre-feet each year for delivery to Mexico. The plant is currently in a ready reserve mode. The plant will be brought back online as river conditions demand and funding is available. Wellton-Mohawk Irrigation and Drainage District This program, authorized by section 101(b) of the Salinity Control Act (Public Law 93-320), has reduced WMIDD irrigation drainage pumping by removing some lands requiring high water use from irrigation and by increasing irrigation efficiencies. Acreage Reduction Program-Under this program, WMIDD irrigable lands were reduced from 75,000 to 65,000 acres. About 6,200 acres of land were purchased from 85 landowners. The remaining 3,800 acres were Federal lands from which irrigable status was withdrawn. Approximately 4,600 of the irrigable acres purchased were in crop production. As a result of the land purchases, deep percolation was reduced by about 29,800 acre-feet per year. This program was completed in 1978. Wellton-Mohawk Irrigation Efficiency Improvement Program-Several entities cooperated on this program, including the WMIDD and its farmers, several Government agencies (Reclamation, Soil Conservation Service (SCS), U.S. Salinity Lab, and the Agricultural Research Service), and the University of Arizona Cooperative Extension Service. Individual measures are discussed in the following sections. Onfarm Improvements Program-The objective of this program was to increase onfarm irrigation efficiencies by improving onfarm irrigation systems and management practices. SCS provided design, installation, and management assistance for approximately 48,000 acres of land. Significant accomplishments included lining 263 miles of onfarm canals; leveling 44,415 acres of land; making soil improvements on more than 3,000 acres; and installing 10 drip irrigation systems and 10,600 onfarm water-control and measurement structures. The Federal Government contributed 75 percent of the costs; farm cooperators contributed the other 25 percent. Irrigation Management Services Program-Reclamation provided technical assistance through the Irrigation Management Services (IMS) Program, which, in turn, provided onfarm, field-by-field irrigation scheduling assistance. From 1977 46