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<br />002864 <br /> <br />. <br /> <br />. <br /> <br />3) Required 602 (a) Storage volume = Average Annual Upper <br />Basin depletion reduced by an allowable shortage of <br />6.12 % + 8.23 maf assumed minimum annual objective <br />delivery - 12.18 maf average natural flow at Lees Ferry <br />during the 1953-1964 critical record period. The sum <br />of all this times the number of years in the critical <br />record period (12). <br /> <br />4) Upper Basin Storage Required = Value in (3) + the live <br />storage needed to maintain the minimum power pools-rn- <br />CRSP reservoirs, which presently is 5.179 maf. <br /> <br />5) Final Upper Basin Storage Required = Value in (4) + <br />annual sediment accumulation above minimum power pool. <br />(78% of the annual sediment accumulation of 61,000 <br />a.f. in Powell) times the number of years of sectiment <br />accumulation in Powell. <br /> <br />Further explanation of the 602 (a) storage computation is <br />provided on pages 36 and 37 of the "CRSS System Overview." <br />Attached is a table that demonstrates what 602 (a) storage <br />requirements would be under varying levels of upper basin <br />depletions in CRS~l. The shortcoming of the table is that it does <br />not vary the critical record period as the program may do. <br />Nonetheless, the values should be close enough to demonstrate the <br />irr~act this method has on 602 (a) storage values as opposed to <br />those in previous studies partially represented by tile attached <br />curve. As can be seen the present 602 (a) storage requirements <br />under CRSSjCRSt1 limit the Colorado River Storage Project <br />protection to slightly more than the minimum power pools. This <br />allows equalization between Powell and Mead to occur much more <br />frequently, a fact supported by the recent ReClamation study <br />comparing CRSP model to CRSSjCRSM model water supply results for <br />CAP. <br /> <br />Article II of the Coordinated Long Range Operating Criteria, <br />requires the following: <br /> <br />(1) The annual plan of operation shall include a <br />determination by the Secretary of the quantity of water <br />considered necessary as of September 30 of that year to <br />be in storage as required by Section 602(a) of P.L. <br />90-537 (hereinafter "602(a) Storage"). The quantity of <br />602(a) Storage shall be determined by the Secretary <br />after consideration of all applicable laws and relevant <br />factors, including, but not limited to, the following: <br /> <br />a. Historic streamflows; <br />b. The most critical periOd of record; <br />c. PrObabilities of water supply; <br /> <br />-2- <br />