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..... ....... ....... .- COLORADO RIVER STUDIES OFFiCE..... ....... ..-.. ..-.. ~ ..... .... ....... ..... ....... ....... ....... ....... ~NEWSLETTER ~ ....... ...; ....... .... Volume 4 January 1992 Alternatives Selected for Analysis > in the Draft EIS The EIS team has recommended seven alternatives for detailed analyses in the Glen Canyon Dam Environmental Impact Statement. Ten preliminary alternatives were described in the March 1991 newsletter and presented at public meetings during April in Flagstaff, Phoenix, and Salt Lake City. After review of public comments on the preliminary alternatives and further scientific studies, the EIS team developed seven alternatives and presented them to the cooperating agencies and interested parties in September 1991. (See related article on Public Comment on Preliminary Alternatives.) These seven alternatives fit into two groups-Steady Flow and Fluctuating Flow. Each alternative will have built-in operational flexibility to reduce spills, maintain conservation storage, and balance storage between Lake Powell and Lake Mead. The parameters of the alternatives are identified in the table on page 4, and a brief summary of each alternative follows. (Continued on page 5) Interim Operating Criteria Implemented On November 1, 1991, the Secretary of the Interior implemented the Interim Operating Criteria at Glen Canyon Dam as a temporary measure designed to reduce adverse impacts on downstream resources until completion of the EIS and a final decision is reached on the operation of the dam. These criteria also allow for the continued gathering of information pending completion of the EIS. The Interim Operating Criteria: . Limit daily fluctuations (over a 24-period) to 5,000,6,000, or 8,000 cubic feet per second (ds) (or a 3-foot fluctuation in the river stage in the Grand Canyon), depending on monthly release volumes . Limit maximum flows to 20,000 cfs, with releases greater than 20,000 cfs, only if necessary to avoid anticipated spills, requiring further evaluation and consultation . Limit minimum flows to 8,000 cfs between 7 a.m. and 7 p.m. and 5,000 ds at night . Limit ascending ramping rates to 2,500 cfs per hour, not to exceed 8,000 cfs in 4 hours . Limit descending ramping rates to 1,500 cfs per hour The scheduled annual and monthly release volumes will be determined using existing practices based on considerations for maintaining conservation storage; avoiding spills; balancing storage between Lakes Powell and Mead; and when possible, meeting power (Continued on page 3) INSIDE THIS ISSUE: Rick's Remarks. . . . , , . . . . . . . . . . . ,. 2 Monitoring Program , . . . . . . . . , . . , . .. 2 Public Comments on Preliminary Alternatives. 10 Colorado River Studies Office Staff . . 11 Southwestern Willow Flycatcher. . . . . . , . . 12 Western's Electric Power Marketing EIS Update: Alternatives Developed .. . . . . . 13 Where Do We Go From Here? ......... 13