OCR Text |
Show -13- much of the silt is deposited. It is in this manner that the low alluvial bottom lands along the river have been formed. Thru these low-bottom lands, the river channel is not usually welll defined and is subject to erratic changes in position and cross-section. These bottom lands along the lower courses of the river are composed of a light silt of wonderful fertility, and in their natural state support a dense growth of mes-quite, arrow-weed, grease-wood, salt-brush and grass, with cotton-wood and willow along the river and sloughs. Occasionally, comparatively small tracts of land are rendered worthless by the presence of sand dunes and much of it is traversed by numerous sloughs,-former river channels,-which have water in them only during high stages of the river. These low-land valleys are for the most part subject to overflow during the early summer flood. Bordering the bottom land of these lower valleys, and at an average elevation of 50 feet higher on their outer margin, are extensive gravelly mesas, the surface of which is gently rolling. The steep gravelly slope between mesa and river bottom is cut back in many places by arroyos or washes formed by the drainage from the mesa lands, and there are usually extensive "fans" or deltas where these arroyos spread out upon the bottom lands. The characteristic vegetation of these mesas is the didiondilla or creosote brush, often erroneously called grease-wood. This gives way on the higher slopes to a growth of iron-wood and many varieties of cacti. Along the steep outer slope of the mesa and in the arroyos, is found the pala-verde, and occasionally small mesquite. The mesquite of the bottom lands grows to a large size, trees 12 to 24 inches in diameter and 20 to 30 feet |
Source |
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. |