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<br />BIOLOGICAL ASSESSMENT- <br /> <br />1\.T""" 11""\ nvC'vn'!I'"\Tn nnI:'n .... Trn1\.TC" <br />l"rlI. " ......U'-' .A.'-&..:.\JA..:.I.' " '-' ....... '-'.I. .A.:.I..I.'-l"'1.A. 1.'-'1 "ltJ <br /> <br />INTRODUCTION <br /> <br />This Biological Assessment is prepared pursuant to Section 7 of the Endangered Species Act of <br />1973 (ESA), as amended, to address impacts of reo per at ion of Navajo Reservoir to threatened or <br />endangered species, species that are candidates for listing, and other special status species <br /> <br />Navajo Dam and Reservoir were constructed between 1958 and 1963 under the Colorado River <br />Storage Project Act of 1956 to meet multiple water resource purposes. The dam is located on the <br />San Juan River approximately 44 miles upstream from Fanningron, New Mexico. The reservoir <br />created holds approximately 1.7 million acre-feet of water and extends upstream into both New <br />Mexico and Colorado. <br /> <br />[n addition to regulating river flows, the reservoir stores water for the Navajo Indian Irrigation <br />Project (NIIP) and various municipal and industrial uses. At the present time, NIlP diverts an <br />average of approximately 160,000 acre-feet from the reservoir for irrigation south of Fanningron. <br />[n the future this use will approximately double. The storage and release of water for historic <br />downstream uses allows upstream diversions to be made for the San Juan-Chama Project as well <br />as providing flood control, recreation, and fishery benefits. The reservoir has a surface area of <br />15,610 acres and has 150 miles of shoreline. The normal operating range for the reservoir is <br />between 5,990 feet and 6,085 feet. Below 5,990 feet is the inactive pool containing 662,000 <br />acre-feet of water. <br /> <br />The Fish and Wildlife Service (Service) (1991) concurred with a request from Reclamation that <br />consultation on the operation of Navajo Dam and Reservoir under Section 7 of the ESA be <br />extended while research was conducted on flow needs of endangered fish in the San Juan River. <br />During the research period, which extended from 1991 to 1997, Reclamation provided test flows <br />to mimic a natural hydrograph. Following the research period a report on flow recommendations <br />was prepared (Holden, 1999). <br /> <br />~. <br /> <br />The Service and Reclamation have consulted formally and informally regarding the potential <br />impacts of reo per at ion of Navajo Reservoir to protected species. Reclamation plans to <br />implement the proposed action-intended to meet flow recommendations for endangered fish-by <br />modifying the operation decision criteria of Navajo Dam to provide sufficient releases of water at <br />times, quantities, and durations necessary to protect endangered fish and their designated critical <br /> <br />2 <br /> <br />00680 <br />