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I I I I I I I I I 000112 Diversion locations 2 and 3 above represent the flow to California irrigation districts on Figure 3, Under the Rule an authorized entity will use existing facilities to deliver water in satisfaction of a SIRA. A more detailed discussion ofLCR operations and maintenance is contained in Reclamation's 1996 Biological Assessment for Description and Assessment of Operations, Maintenance, and Sensitive Species of the Lower Colorado River (LCRBA), Figures 4, 5, and 6 display fluctuations in the water level of Lakes Mead, Mohave, and Havasu respectively over a seven year period, Lake Mead is the principal storage reservoir of these three and the source for meeting downstream water use of the Lower Division States, Water levels at any time are a direct result ofthe relationship of releases from Glen Canyon Dam, tributary inflow below Glen Canyon Dam, and releases from Hoover Dam. The pattern of fluctuation in water elevations on Lake Mead is very minimal on a daily basis because of the capacity of this reservoir. The patterns shown in Figure 4 primarily reflect seasonal drawdown during the spring and summer to meet water orders, equalization with Lake PoweU, and variation in water supply, Fluctuations in the water elevations of Lake Mohave (Figure 5), represent operation of Davis Dam to facilitate water deliveries to Mexico and the other downstream water users, and to re-regulate the flows from Hoover Dam. Fluctuations in Lake Mohave are restrained to a maximum drawdown of one foot per week to meet endangered species needs, I I I I I I I I I I Parker Dam was constructed to create a forebay, resulting in Lake Havasu, for the MWD Whitsett pumping facility, Later, the CAP was constructed just downstream on the Arizona side of Lake Havasu and similarly uses the lake as a forebay for pumping water into the CAP aqueduct system, Because of this, Lake Havasu typically fluctuates within an elevation of about four feet during the year (Figure 6) and is relatively stable, The patterns of historical and projected releases out of Hoover Dam (Figure 7) are very similar. These releases generally reflect the delivery of water for downstream use in Arizona, California, and Mexico, Preferred Alternative Under the Preferred Alternative, in a normal year, the basic annual apportionments available for consumptive use to each of the Lower Division States would not change, Arizona would continue to use its entire 2,8 maf annual apportionment through direct use and intrastate storage, However, the AWBA may forego storage on its own behalfin order to make some of Arizona's apportionment available for storage on behalf of California or Nevada through the interstate component of the A WBA Act, If Arizona makes a portion of its apportionment available to California or Nevada for storage off stream, that will not significantly change the distribution or delivery of Colorado River water. The water would continue to be distributed through the normal conveyance system, primarily the CAP facilities, The only differences would be that the consuming State entity will pay for the cost of acquiring, delivering, and storing the Colorado River water in Arizona and the water stored offstream under a SIRA will belong to the storing 12