Brooks Meredith Smith, Justin T. Wong, Troutman Sanders, Richmond, VA, for Petitioner, Kristy A. N. Bulleit, Karma B. Brown, Kerry L. McGrath, Andrew Turner, Hun-ton & Williams, Washington, DC, for In-tervenor Utility Water Act Group, Jessica O’Donnell, Amy J. Dona, Andrew J. Doyle, Martha Mann, U.S. Department of Justice, Environment & Natural Resources Division, Washington, DC, for Respondents United States Environmental Protection Agency, Gina McCarthy, United States Army Corps of Engineers, John McHugh, Jo-Ellen Darcy, Timothy S. Bishop, Mayer Brown, Chicago, IL, Michael B. Kimberly, Mayer Brown, Washington, DC, John Quentin Melcher Riegel, National Association of Manufacturers, Washington, DC, for Inter-venor National Association of Manufacturers, Jennifer Ann Sorenson, Natural Resources Defense Council, San Francisco, CA, for Intervenors Natural Resources Defense Council, Inc., National Wildlife Federation, Catherine Wannamaker, Christopher Kaltman DeScherer, Senior Attorney, Southern Environmental Law Center, Charleston, SC, Megan Hinkle, Southern Environmental Law Center, Atlanta, GA, for Intervenors One Hundred Miles, South Carolina Coastal Conservation League, James N. Saul, Lewis & Clark Law School, Portland, OR, for Intervenors Wat-erkeeper Alliance, Center for Biological Diversity, Center for Food Safety, Humboldt Baykeeper, Russian Riverkeeper, Monterey Coastkeeper, Snake River Wat-erkeeper, Upper Missouri Waterkeeper, Turtle Island Restoration Network, Janette K. Brimmer, Jennifer C. Chavez, Earthjustice, Seattle, WA, for Interve-nors Puget Soundkeeper, Sierra Club, Philip Bein, Assistant Attorney General, Office of the Attorney General of New York, Albany, NY, Timothy Hoffman, Office of the Attorney General of New York, Buffalo, NY, for Intervenor State of New York, Kirsten S. P. Rigney, Office of the Attorney General of Connecticut, Hartford, CT, for Intervenor State of Connecticut, Edward Grant Bohlen, Office of the Attorney General of Hawaii, Honolulu, HI, for Intervenor State of Hawaii, Seth Schofield, Office of the Attorney General Massachusetts Energy and Environment Bureau, Boston, MA, for Interve-nor State of Massachusetts, Lorelei M. Bensel, Oregon Department of Justice, Salem, OR, Paul Garrahan, Oregon Department of Justice, Natural Resources Section, Portland, OR, for Interve-nor State of Oregon, Benjamin D. Battles,.Office of the Attorney General of Vermont, Montpelier, VT, for Intervenor State of Vermont, Ronald Lavigne, Office of the Attorney General, Ecology Division, Olympia, WA, for Intervenor State of Washington, Loren L. AliKhan, Office of the Attorney General of the District of Columbia, Washington, DC, for Intervenor District of Columbia, Andre Monette, Best, Best & Krieger, Washington, DC, for Amici Curiae Association of California Water Agencies, National Water Resources Association, Eastern Municipal Water District, San Diego County Water Authority, Santa Fe Irrigation District, Helix Water District, Santa Margarita Water District, L. Rachel Lerman, Barnes & Thorn-burg, Los Angeles, CA, for Amicus Curiae 21 Senators and 67 Representatives, Lisa Ann Kirschner, Parsons, Behle & Latimer, Salt Lake City, UT, for Amicus Curiae National Rural Water Association, Richard Abbott Samp, Washington Legal Foundation, Washington, DC, for Ami-cus Curiae Washington Legal Foundation, Charles C. Caldart, National Environmental Law Center, Seattle, WA, Heather A. Govern, National Environmental Law Center, Boston, MA, for Amici Curiae Local Elected Officials, Small Business Founders, Owners or Operators, Susannah Weaver, Donahue & Goldberg, Washington, DC, for Amicus Curiae Environmental and Administrative Law Professors, Royal Gardner, Stetson University College of Law, Gulfport, FL, Stephanie Tai, University of Wisconsin Law School, Madison, WI, for Amicus Curiae Wetland and Water Scientists, Sam Kalen, Law Office, Laramie, WY, for Amicus Curiae Current and Former Members of Congress, Melinda Kassen, Waterjamin Legal & Policy Consulting, Boulder, CO, for Amici Curiae Trout Unlimited, American Fly Fishing Trade Association, Izaak Walton League of America, Theodore Roosevelt Conservation Partnership