OCR Text |
Show 140 PROBLEMS OF IMPERIAL VALLEY AND VICINITY. main streams of the Grand River basin. A dam just below the mouth of the Dolores will impound 2,270,000 acre-feet by raising the water surface 215 feet. Further raise would cover the tracks of the main, line of the Denver & Rio Grande Railroad. This reservoir is part of th pip^uf storage on tributaries for the Imperial Valley and is the most valuable site on the tributaries for that purpose. Silt.-It has been estimated that the »ver carries 10,000 acre-feet of silt annually past this site, which will necessitate some provision for silt storage. Power.-To equate the river for power here would require roughly between 4,000,000 and 4,500,000 acre-feet of storage. It is impossible to secure so much storage because of the Denver & Rio Grande Railroad, but if, of the 215 raise, the upper 65 feet be devoted to regulating storage which will give 1,500,000 acre-feet, 770,000 acre-feet of dead or silt storage and 150 of head for power will result. Below the reservoir site the river flows 125 miles to its junction with the Green to form the Colorado, and has a total fall of 200 feet in addition to what can be created at the reservoir. Potential continuous horsepower at turbine, 88 per cent efficiency, is as follows: At dam site............................................................. 90,000 Between dam and mouth................................................. 120,000 Total............................................•................. 210,000 MAIN STEM OF GRAND RIVER. The Grand joins the Green in Utah to form the Colorado. The general course of the river is southwest from the high mountains of the Continental Divide. Irrigation diversion from the tributaries, both at the headwaters and along the river, is comparatively easy and water abundant, so that until in the vicinity of Grand Junction development to date has been by individual effort. As it flows westward from the mountains the river has cut its way deep into the soft, sedimentary rocks which characterize the Colorado Basin. Long narrow valleys alternate with deep canyons with the result that from the main river in this region there will never be any great amount of irrigation. Lower down in the vicinity of Grand Junction the valley has been eroded into comparatively broad mesas which can be reached by long ditches from the river. Here is a compact body of irrigable land which is now covered by private ditches and by the Grand Valley project of the Reclamation Service. Down river from this project, which is close to the Colorado-Utah line, the river flows in deep canyons from which it is impossible to divert for irrigation. One known reservoir site exists at Dewey where the Dolores River enters the Grand. This site, the Dewey, is p»rt of the plan for developing storage on tributaries for Imperial Valley. Precipitation ranges from 8 inches at Grand Junction on the west to 24 inches at Breckenridge on the east and much more in the mountain areas. A little over 50 per cent comes in the growing season and about 35 per cent May to August, inclusive. The average summer period between frosts ranges from 180 days at Grand Junction to 35 days at Breckenridge. Elevation of irrigable land ranges from 4,500 on the west to 9,500 on the east. Mean annual temperature ranges |
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] : |