WSP06656 - Laserfiche WebLink

Home Browse Search

- DEC- 3-96 TUE 9:2~ UPPER COLORADO ~IVER COMM P_B:2 - Option II - Drain Laka Powell to minimum-power head and maintain as nnrly al possibll (:I: elavation 31100'). This propoul would llave approximately 6 maf of storage at Lakl Powell of which :I: 2 million would be dead. The :I: 4 million of actlvs storage oapaclty would be raquired to milintain minimum power held and would only be useable to meet downstream demanda IF the pow" aystem were shut downl . Only present level, of use of Colorado River wners could be maintained without Ilgnifieant end axtrema risk to both wetar ~pply and power supplies. Approximate 1.7 million acrl flllt of future use of Colorado River water would have to be forgone In the Upper Basin. . Power genaratlon at Lake Powall would ba reduoed by 1 300 glglwatt hours (:I: 30%). Power gen.ratlon at Lak. Mild would inern.. about 17% (650 gigawatt hours). Nat Iyatlm lInergy produotion would be reduced 690 gigawatt hour. or :I: 9%. ,..... . Water ual' In the Lower Basin would incr.... by an average of 240,000 af and to nearly 600,000 af by 2080. Thla Increau In dallvery would sllminata tha expactad ultimat. ahortage. to the Centrel Arizona Projlct. The riak of flood control releasel would Inorea'l from 17'111 to 27%. . Twenty mil.. of atrlam channel would bl rlcovered In eaoh of the Colorado mlinst.m, and San Juan Rlvlr drainages. Approximately 16 mllal of thl elcBlante Rivar would be recoverad. Some of thll benefit would be lo.t In veara of .bove average runoff as the runoff II temporarily storad at Lake Powell due to Insufficient r,lease ceplcltles 146,000 cfs). As muoh aa :I: 70 feet of vacated reservoir spsce would be required to pili tha runoff experlenced In 1983 or t 984 (reservoir .I.vltlon - 3670 :1:). . Evaporation It Lake POWIlI would be reduQld by 55'l!. I z 320,000 af) but evaporation would Increase by 9'l!. (70,000) at LIke Mild leaving I net decrease in evaporsticn of 260,000 sf or 20'1& of total system eVlpOr.tlon. r- ..