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Show 54 there were 905,560 acres within the District0 and ultimate gross area is expected to be nearly 1,000,000 acres7. 474,555 acres were irrigated in 1955.8 The area encompassed by the District is arid. It has an average annual rainfall of three inches and there has been less than one-half inch of rain in some years. The mean annual temperature is 72 degrees and 110 days a year, on the average, have maximum temperatures of over 100 degrees. The sole source of irrigation water has been the Colorado River. Availability of underground water for irrigation purposes is in dispute.9 Water deliveries from the Colorado River to the Imperial Valley were first made at the turn of the century10 and, over the years, several diversion points in both the United States and Mexico were employed. In 1907 water was first diverted at Hanlon Heading into the Alamo Canal, which lay partly in Mexico and entered the United States near Mexicali.11 In 1918 a new diversion point, Rockwood Gate, went into operation upstream from Hanlon Heading and remained the primary diversion point until the All-American Canal was constructed.12 Construction of the canal was commenced in 1934. However, because of difficulties in the operation of Imperial Dam, which was 6Calif. Ex. 238. For the acreage additions from 1911 to 1956 see Calif. Ex. 238. 7Tr. 7902-7903 (Dowd). 8Tr. 8115 (Dowd). For annual irrigated acreage figures see Calif. Exs. 270-271. °Dowd, a well qualified California witness, testified that there is no supply of potable underground water in the District. Tr. 6475-6476. In this connection, it should be noted that Imperial Valley, a major portion of the District, is a part of the Colorado River Delta which is a large area of silt deposits sometimes reaching a depth of 1,000 feet. Tr. 647S, 6495 (Dowd). 10Tr. 7312-7315 (Dowd). nTr. 6917 (Dowd). 12Tr. 7491, 7799 (Dowd). |
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Original Report: 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 |