OCR Text |
Show No consideration has been given to the ultimate stream flow available at Boulder Canyon since the matter of primary interest is the power output which will be available during the 50-year repayment period for amortization of construction advances. Even the repayment period is so long that the estimate of run-off conditions as far ahead as 1988 may be far astray. FLOOD CONTROL Maximum discharges at Boulder Canyon. In view of the large increase in construction diversion capacity recommended by the Colorado River board, further studies have been made of the annual flood peaks that have passed Boulder Canyon. Expressed in terms of probability, the results are as follows: Frequency with which discharge will be equaled Discharge in ____________________or exceeded__________________ second-feet Once in 5 years........................................................................ 130,000 Once in 10 years...................................................................... 160,000 Once in 20 years...................................................................... 190,000 Once in 50 years...................................................................... 230,000 Once in 100 years.................................................................... 260,000 Once in 500 years.................................................................... 320,000 Once in 1,000 years.................................................................. 360,000 Once in 10,000 years................................................................ 450,000 During the period of discharge measurements at Yuma, 1902-1929, maximum discharges at Boulder Canyon have equaled or exceeded 100,000 second-feet on 17 separate occasions, 150,000 second-feet on 6 occasions, and 200,000 second-feet on 2 occasions, with a maximum of 210,000 second-feet. The flood of 1884 is estimated to have had a peak of 250,000 to 300,000 second-feet. The storage capacity behind the construction diversion works is small but a break may nevertheless do some damage. The need for reassurance of downstream inter- |
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. |