172
Opinion of the Court
as habitat for migratory birds. As counsel for respondents conceded at oral argument, such a ruling would assume that "the use of the word navigable in the statute . . . does not have any independent significance." Tr. of Oral Arg. 28. We cannot agree that Congress' separate definitional use of the phrase "waters of the United States" constitutes a basis for reading the term "navigable waters" out of the statute. We said in Riverside Bayview Homes that the word "navigable" in the statute was of "limited import," 474 U. S., at 133, and went on to hold that § 404(a) extended to nonnavigable wetlands adjacent to open waters. But it is one thing to give a word limited effect and quite another to give it no effect whatever. The term "navigable" has at least the import of showing us what Congress had in mind as its authority for enacting the CWA: its traditional jurisdiction over waters that were or had been navigable in fact or which could reasonably be so made. See, e. g., United States v. Appalachian Elec. Power Co., 311 U. S. 377, 407-408 (1940).
Respondents—relying upon all of the arguments addressed above—contend that, at the very least, it must be said that Congress did not address the precise question of § 404(a)'s scope with regard to nonnavigable, isolated, intrastate waters, and that, therefore, we should give deference to the "Migratory Bird Rule." See, e. g., Chevron U. S. A. Inc. v. Natural Resources Defense Council, Inc., 467 U. S. 837 (1984). We find § 404(a) to be clear, but even were we to agree with respondents, we would not extend Chevron deference here.
Where an administrative interpretation of a statute invokes the outer limits of Congress' power, we expect a clear indication that Congress intended that result. See Edward J. DeBartolo Corp. v. Florida Gulf Coast Building & Constr. Trades Council, 485 U. S. 568, 575 (1988). This requirement stems from our prudential desire not to needlessly reach constitutional issues and our assumption that Congress does not casually authorize administrative agencies to interpret a
Page: Index Previous 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 NextLast modified: October 4, 2007