State of Arizona, complainant v. State of California, Palo Verde Irrigation District, Imperial Irrigation District, Coachella Valley County Water District, Metropolitan Water District of Southern California, City of Los Angeles, California, City of San Diego, California, and County of San Diego, California, defendants : the United States of America and State of Nevada, interveners : State of Utah and State of New Mexico, impleaded defendants : report / Simon H. Rifkind, special master

page 228

228 sion of water above Lake Mead. If Congress authorizes a dam and diversion works on the. mainstream above Lake Mead, its attention will then be directed to the problem of apportioning the water diverted by those structures. At that time Congress can determine whether or not Arizona's diversions above Lake Mead shall be chargeable to her under the present contractual apportionment.86 California strenuously urges that the contractual apportionment explained in this section of the Report is contrary to the "bargain" she made with Congress in enacting the California Limitation Act. According to California, she was assured of 4.4 million acre-feet out of the first 7.5 million acre-feet of consumptive uses of water diverted throughout the entire Colorado River System in the Lower Basin. She calls this "III(a) water," referring to the allocation of 7.5 million acre-feet of system-wide consumptive uses made to the Lower Basin by Article III (a) of the Colorado River Compact. The apportionment suggested in this Report, of course, allocates to California 4.4 million acre-feet out of 7.5 million acre-feet of mainstream uses only. Since California, which has no tributaries, would receive substantially more water under a system-wide apportionment, see pp. 177-178, supra, she claims that the suggested mainstream apportionment diminishes the fruits of her bargain. Since consumptive use of water from the Gila River System in Arizona accounts for most of the tributary uses in the Lower Basin, the real thrust of California's argument is that Arizona's mainstream uses should be curtailed, for the benefit of California uses, to the extent of Arizona uses on the Gila River. California has never clearly designated the ground on which she bases her claim to 4.4 million acre-feet out of a 86The doctrine of equitable apportionment may affect diversions in this reach of the River. See pages 316-318, infra.