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Show THE AT,TrAMERICAN CANAL. 9 the United States. The records of the United States Geological Survey indicate that since 1902 this flow at Yuma has ranged from a minimum of 8,000,000 acre-feet to a maximum of 26,000,000 acre-feet and has averaged somewhat more than 17,000,000 acre-feet per annum. At the lowest stage in the fall and early winter months the discharge of the river at Yuma may drop occasionally 1 > 3,000 second-feet, though the ordinary low-water stage has usually ^ ->en about 4,000 second-feet. At its highest stages the discharge . reported to have exceeded 200,000 second-feet. The ordinary summer maximum flow for the period covered has averaged 94,000 second-feet. There have been times, confirmed by Indian traditions, when the Colorado River delivered its water into the Salton Basin instead of as at present into the Gulf of California. This basin was then an inland sea with a surface area of nearly 2,000 square miles, embracing all of what is now known as Imperial and Coachella Valleys. This sea extended from the Volcano Lake in Lower California northwesterly into California to a point a few miles to the northward of Indio. The greatest depth of this sea was about 320 feet. Its margin is well marked by a beach line which can readily be traced at many points on both sides of Salton Basin. For more than 400 years, and probably for a period of more than 500 years (it may have been considerably longer), the Colorado River has discharged uninterruptedly into the Gulf of California, except only for about one year, 1905 to 1907, when its discharge was temporarily inland into the Salton Sea. The Colorado River at and below Yuma is a muddy stream flowing in a broad bed of sand. The sediment and sand which it transports in suspension and as a bed load if uniformly distributed would cover about 90,000 to 100,000 acres 1 foot in depth on an average per annum. The Gulf of California at one time in the past extended far into California, embracing most of the area now known as Salton Basin, of which the larger portion lies below sea level. The sand and sediment brought down by the river has built up a delta cone whose upper end or apex may be considered to be at Yuma and which spreads out fan-shaped to the south and west, thence with a gentle slope toward the north, far into California. It rounds the southern termination in Mexico of the mesa formation which flanks the right bank of the river. This delta embraces what is known as Yuma Valley on the east side of the river, a small part of Sonora near the upper end of the Gulf of California, the portion of Lower California lying between the river and the Cocopah Mountains except a small area of mesa and sandhill formation which projects over the international boundary from California and except the detrital slope at the base of the Cocopah Range, and also the region at one time known as the New River |
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Original book: [State of Arizona, complainant v. State of California, Palo Verde 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, United States of America, State of Nevada, State of New Mexico, State of Utah, interveners] : California exhibits. |