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2001 DETE&\IlINATIONS d v.- :20-.::z/~ (52000 ~r/ The AO? provides guidance regarding reservoir s{Qrage and release conditions during the upcoming year, based upon Congressionally mandated and authorized storage. release, and delivery criteria and determinations. After meeting these requirements, specific reservoir releases may be modified within these requirements as forecast inflows change in response to climatic variability and to provide additional benefits coincident to the projects' multiple purposes. . Basin Reservoirs The Operating Criteria provide that the annual plan of operation shall include a determination of the quantity of water considered necessary to be in Upper Basin storage at the end of the- water year. Taking into consideration all relevant factors required by the Operating Criteria. it is determined that the active storage in Upper Basin reservoirs forecast for September 30. 2001. exceeds the storage required under Section 602(a) of the Colorado River Basin Project Act under any reasonable range of assumptions which might be applied. Therefore, "602(a) Storage" is not the criterion controlling the release of water from Glen Canyon Dam during water year 2001. Section 602(a)(3) of the Colorado River Basin Project Act provides for the storage of Colorado River water in Upper Basin reservoirs that the Secretary of the [nterior finds necessary to assure deliveries to comply with Articles III(c) and III(d) of the 1922 Colorado River Compact, without impairment to the annual consumptive use in the Upper Basin. Pursuant to Section 602(b), as amended. the Secretary is required to make this determination after consultation with the Upper Colorado River Commission and representatives from the three Lower Division States, and after taking into consideration all relevant factors including historic stream flows, the most critical period of record, the probabilities of water supply, and estimated future depletions. Water not required to be so stored will be released from Lake Powell: to the extent it can be reasonably applied in the States of the Lower Division to the uses specified in Article III(e) of the 1922 Colorado River Compact, but these releases will not be made when the active storage in Lake Powell is less than the active storage in Lake Mead, to maintain, as nearly as practicable, active storage in Lake Mead equal to the active storage in Lake Powell. and to avoid anticipated spills from Lake Powell. The spill avoidance and/or the storage equalization criteria in accordance with Article 11(3) of the Operating Criteria will control the releases from Glen Canyon Darn during water year 2001 unless the minimum objective release criterion in Article 11(2) is controlling. Under the most probable inflow scenario, Glen Canyon Dam will release 11,600 MCM (9.40 MAF). Lower Basin Reservoirs Pursuant to the Operating Criteria and consistent with the Decree, water shall be released or pumped from Lake Mead to meet the following requirements: (.4 U.S.~Mexico Water Treaty obligations; (b) Reasonable beneficial consumptive use requirements of mainstream users in the Lower Division States; (c) Net river losses; (d) Net reservoir losses; (e) Regulatory wastes; and Flood control. <,M",__.__.., .,..-y,.,. :':"~~~c,"_ -, ~')ecr.::[.:..r/vf[helnteriorwilldetermine the extent to which the reasonable beneficial consumptive use requirements of mamstream users are met Iil toe Lower Divlsion States. The reasonable beneficial consumptive use requirements are met depending on whether a nonnal. surplus, or shortage condition has been determined. The normal condition is detined as annual pumping and release from LJ.ke Mead sufficient to satisfy 9,251 MCM (7.500 MAF) of consumptive use in accordance with Article III(3)(a) of the Operating Criteria and Article Il(S)( [) of the Decree. The surplus condition is defined as annual pumping and release from Lake Mead sufficient to satisfy in excess of 9.251 MCM (7.500 MAF) of consumptive use in accordance with Article III(3)(b) of the Operating Criteria and Article II(B)(2) of the Decree. The determination of surplus conditions for 2001 is based on the factors listed in Article IlI(J)(b) of the Operating Criteria. This Article allows for consideration of all relevant factors. including. but not limited to, those specifically listed in the Operating Criteria. Accordingly, several different approaches were considered in making a determination of surplus water supply conditions for use in the Lower Basin States of Arizona. California. and Nevada for calendar year 2001. One of the approaches considered was the seven Colorado River Basin States plan for interim..surplus guidelines. At the speCific request of the Secretary, the seven Colorado Basin States entered into discussions on the development of interim surplus guidelines. Culminating in the spring of 2000, the Basin States successfully developed the seven Colorado River Basin States plan tor interim surplus guidelines. These proposed guidelines were made available as public information during the comment period of the ongoing EIS regarding development of interim surplus criteria. Under the Basin States plan, II releases, given current hydrologic conditions, would only be available to meet domestic purposes. Other approaches considered in making a ination of surplus water supply for calendar year 2001 include the probability of future tlood control releases, the annual operating decisions made over ttk:_ st 5 years, the spill avoidance strategy, the shortage protection strategy, and progress made to date on California's Colorado River Water Use Plan. The Secretary also considered all available public information associated with the EIS on interim surplus criteria. Significant consideration was also given to current reservoir storage and preliminary projections of snowpack and runoff within the Colorado River Basin for water year 2001. Taking all these into account, the determination of a surplus water supply condition in the Lower Basin will govern releases for use in the States of Arizona, Nevada. and California http://www . uc. usbr.gov/wrg/aop/O I aop.draft. html 11117/00 "