AZ vs. CA:13 California Exhibits, Vol. XIII; Nos. 1800-1842; 1901-1906; 2000-2044

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-2- Under the Compact, then, the only water of which the right to exclusive beneficial use in perpetuity may be acquired in the Lower Basin is the water apportioned to that basin. Such apportionment is limited to 7,500,000 acre-feet of water per annum by Article III (a). The Colorado brief, page 40, contends that paragraph (b) of Article III operates to increase this apportionment to 8,500,000 for the Lower Basin. This, we submit, is not the case. If it had been intended to apportion the larger amount, the Compact could easily have said so. The difference in language between paragraphs (a) and (b) is plain, and the difference in meaning is clear. Paragraph (b) does not apportion in perpetuity, as does paragraph (a), any beneficial use of water. It is very careful not to do this. It is to be read with paragraph (c) and relates solely to the method of sharing between the basins any future Mexican burden which this Government might recognize. This burden is to be satisfied first out of "surplus" waters, and surplus waters are defined, not as surplus over quantities "apportioned", but as surplus over quantities "specified in paragraphs (a) and (b)." Any deficiency remaining is to be borne equally by the two basins. Thus the Lower Basin, which without paragraph (b) might use water in excess of its apportionment without acquiring any exclusive right in perpetuity thereto, is enabled to retain such uses to the extent of 1,000,000 acre-feet per annum against the first incidence of the Mexican burden. Thereafter it is entitled to require the Upper Basin to share from its apportionment equally in the satisfaction of any deficiency. In other words, all that paragraphs (b) and (c) accomplish is to require the Upper Basin to reduce its apportionment in favor of Mexico before the Lower Basin is required to do so, the Lower Basin being entitled to contribute first, to the extent of