Brad Bennett; Mario Giordano; Langell Valley Irrigationdistrict, a Political Subdivision of the State of Oregon;horsefly Irrigation District, a Political Subdivision of Thestate of Oregon, Plaintiffs-appellants, v. Marvin L. Plenert, in His Official Capacity As Regionaldirector, Region One, Fish and Wildlife Service, U.s.department of the Interior; John F. Turner, in His Officialcapacity As Director, Fish and Wildlife Service, U.s.department of the Interior; Bruce Babbitt, in His Officialcapacity As Secretary, U.S. Department of the Interior,defendants-appellees