OCR Text |
Show -15- years from known lake levels, known lake area, estimated evaporation rates, and allowances for increasing depletions for irrigation uses. From such estimates it appears that there have been three periods of low run-off in 78 years, each of which closely approximated that of 1900-1905, inclusive, in total run-off for the 6-year period, one of these having a total 6 per cent below and the other 4 per cent above the late period. There are, furthermore, other periods with conditions only moderately better. Firm power should, therefore, be based on the output obtainable in the low run-off period immediately following 1900. It has been decided that a maximum monthly shortage of 10 per cent in firm power output will be permissible. With declining storage, increasing outflow is necessary for full power output. When such depletion is carried too far, undesirable results obtain in that the maximum power shortage becomes unduly high, irrigation shortages are invited, and total power output during the critical period is depressed by the continuance of low heads. To meet this situation, an empirical rule has been adopted for a maximum permissible draft of 15,000 second-feet under 1938 conditions whenever the storage level is below 15,000,000 acre-feet; and of 14,000 second-feet under 1988 conditions whenever the storage level falls below 15,000,000 acre-feet. The resulting firm power for various maximum high-water levels is as follows: Firm power out- Firm power out- put under 1938 put under 1988 Maximum Raise in conditions (horse- conditions (horse- water level, river power, continu- power, continu- feet (feet) ous output ous output) 1.204 557 608.000 543.000 1,222 575 650.000 582,000 1.229 582 663.000 594.000 |
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. |