AZ vs. CA:04 California Exhibits, Vol. IV; Nos. 151-192

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a huge flat ridge of silt, which slopes from the river northward down to the lands of the Imperial Valley in the United States. A large area of the Imperial Valley, embracing most of the lands now under cultivation, lies below sea level. The soil of the delta and of the Imperial Valley is light, friable, and easily eroded. As a consequence the river cuts its banks with extreme rapidity in flood, and there is a constant tendency for the river to form for itself new channels. The Imperial Valley is therefore under the constant menace of permanent inundation by a break of the river down the ridge into the valley. Irrigation is necessary for the cultivation of all lands in the lower part of the basin of the Colorado. As the valley of the river, until it approaches its delta cone, is generally narrow, the amount of irrigable lands is limited. The Imperial Valley, with the adjacent land in Mexico, embraces the major portion of the land readily watered from the Colorado, and the cheapest and most easily maintained routes for irrigation channels to a large part of the basin included within United States territory lie through Mexico. The lands now under irrigation in the Imperial Valley are irrigated through such a route. The Imperial Irrigation District comprises about 575,000 acres of land, mostly arable. The valley slopes down to Salton Sea, the surface of which is about 235 feet below sea level. The District is irrigated by means of a canal taking water from Colorado River on the California side through gates called the Hanlon Heading, a short distance above the Mexican line. The water is conducted a few miles in a canal constructed parallel with the river, and continues in Mexico, following a natural channel known as the Alamo Canal for a long distance in a