OCR Text |
Show -11- From the above table it would appear that the 1884 flood was one of near maximum proportions. This conclusion is supported by accounts of stream-bed conditions found in the description of the Redrock Bridge in volume 25, Trans. A. S. C. E. In 1881 soundings were made for bedrock. In 1888, after the high flood of 1884, the so-called bedrock of 1881 was found to have been replaced by drift sand, gravel, and bowlders. Apparently the material taken for bedrock in 1881 had been in place for a period bordering on a geologic age permitting extensive compacting. Flood control capacity and releases. Studies of the relation of rainfall and run-off in the past 30 years indicates that run-off can be predicated to a considerable degree and reservoir operations conducted to take advantage thereof. Rainfall data for 1884 are meager as the Weather Bureau was not then in existence; nevertheless, there were strong indications toward the end of winter of heavy run-off. It has been concluded that operation can be so conducted as to result in a distributed reservoir outflow substantially as follows: Second-feet April ............................................................................ 55,000 May .................................................,............................ 65,000 June .............................................................................. 75,000 July ..................................................................................75,000 August .......................................................................... 50,000 River losses and irrigation diversions, including the All-American Canal, would reduce these flows by 13,000 second-feet in their passage to Yuma. With such outflow, the requisite flood control capacity is 9,500,000 acre-feet with upstream development as estimated for 1938 and 4,000,000 acre-feet with upstream development as of 1988. These reservations for flood con- |
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. |