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Title I Program Colorado River Basin Salinity Control Act Protective and Regulatory Pumping Unit Section 103(a) of Public Law 93-320 authorized the construction, operation, and maintenance of the PRPU to manage and conserve United States ground water for the benefit of the United States and for delivery to Mexico. The PRPU is located in a 5-mile-wide zone along the Southerly International Boundary between Arizona and Mexico. (See frontispiece map.) The PRPU was developed to intercept part of the ground-water underflow that moves southward from the Yuma Mesa in the United States into Mexico. Before the PRPU was constructed, this underflow was increasing because of ground-water pumping in the Sonora Mesa Well Field, immediately south of the Southerly International Land Boundary in Mexico. The Basin States expressed their concern about the pumping in their July 1973 letter to the President. Currently, 21 of the planned full com- plement of 35 wells and associated conveyance and energy facilities have been constructed. The wells are connected by a I5.3-mile pipeline and open concrete-lined canal that carries water by gravity across the Southerly International Land Boundary. With 35 wells, the PRPU would be capable of producing about 160,000 acre-feet of water per year. illtimately, approximately 125,000 acre-feet of water from the PRPU, combined with 15,000 acre-feet of water from wasteways and drains in the Yuma Valley, would furnish 140,000 acre-feet of Mexico's 1.5-million-acre-foot annual entitlement. The water will be delivered at the Southerly International Land Boundary near San Luis, Arizona. Currently, water from wasteways and drains in the Yuma Valley exceeds 15,000 acre-feet per year. 16 Should these wasteway and drain flows diminish in the future, wells will be added to the PRPU, as needed, to ensure that approximately 140,000 acre- feet can be delivered at the Southerly International Land Boundary at all times. Additionally, as authorized by Title I, approximately 23,500 acres of private, State, and State-leased lands have been acquired within the 5-mile zone. The purpose of these acquisitions is to limit development and thus limit United States ground-water pumping to 160,000 acre-feet per year, as required by Minute No. 242. Acquisitions were completed in 1984. Fish and Wildlife Mitigation Measures Public Law 93-320, as amended by Public Law 96-336, authorized mitigation of fish and wildlife habitat losses attributable to Title I projects, including: . Loss of wetlands and seep areas along the Coachella Canal caused by concrete lining. . Deer drownings in the concrete-lined section of the Coachella Canal. . Reduction in agricultural acreage in the WMIDD. . Loss of surface water in the Colorado River below Morelos Dam caused by conveying WMIDD irrigation drainage in the Bypass Drain to the Santa Clara Slough. Several measures were implemented to mitigate these impacts: . A water well for wildlife use is being constructed near Tacna, Arizona. . An old boITOw pit near Fortuna Wash and the Gila River east of Yuma, Arizona, was deepened to improve habitat for fish.