Chief Justice Rehnquist delivered the opinion of the Court.

    Section 404(a) of the Clean Water Act (CWA or Act), 86 Stat. 884, as amended, 33 U.S.C. § 1344(a), regulates the discharge of dredged or fill material into “navigable waters.” The United States Army Corps of Engineers (Corps), has interpreted §404(a) to confer federal authority over an abandoned sand and gravel pit in northern Illinois which provides habitat for migratory birds. We are asked to decide whether the provisions of §404(a) may be fairly extended to these waters, and, if so, whether Congress could exercise such authority consistent with the Commerce Clause, U.S. Const., Art. I, §8, cl. 3. We answer the first question in the negative and therefore do not reach the second.

    Petitioner, the Solid Waste Agency of Northern Cook County (SWANCC), is a consortium of 23 suburban Chicago cities and villages that united in an effort to locate and develop a disposal site for baled nonhazardous solid waste. The Chicago Gravel Company informed the municipalities of the availability of a 533-acre parcel, bestriding the Illinois counties Cook and Kane, which had been the site of a sand and gravel pit mining operation for three decades up until about 1960. Long since abandoned, the old mining site eventually gave way to a successional stage forest, with its remnant excavation trenches evolving into a scattering of permanent and seasonal ponds of varying size (from under one-tenth of an acre to several acres) and depth (from several inches to several feet).

    The municipalities decided to purchase the site for disposal of their baled nonhazardous solid waste. By law, SWANCC was required to file for various permits from Cook County and the State of Illinois before it could begin operation of its balefill project. In addition, because the operation called for the filling of some of the permanent and seasonal ponds, SWANCC contacted federal respondents (hereinafter respondents), including the Corps, to determine if a federal landfill permit was required under §404(a) of the CWA, 33 U.S.C. § 1344(a).

    Section 404(a) grants the Corps authority to issue permits “for the discharge of dredged or fill material into the navigable waters at specified disposal sites.” Ibid. The term “navigable waters” is defined under the Act as “the waters of the United States, including the territorial seas.” §1362(7). The Corps has issued regulations defining the term “waters of the United States” to include
“waters such as intrastate lakes, rivers, streams (including intermittent streams), mudflats, sandflats, wetlands, sloughs, prairie potholes, wet meadows, playa lakes, or natural ponds, the use, degradation or destruction of which could affect interstate or foreign commerce … .” 33 CFR § 328.3(a)(3) (1999).

In 1986, in an attempt to “clarify” the reach of its jurisdiction, the Corps stated that §404(a) extends to instrastate waters:

“a.  Which are or would be used as habitat by birds protected by Migratory Bird Treaties; or
“b.  Which are or would be used as habitat by other migratory birds which cross state lines; or
“c.  Which are or would be used as habitat for endangered species; or
“d.  Used to irrigate crops sold in interstate commerce.” 51 Fed. Reg. 41217.

This last promulgation has been dubbed the “Migratory Bird Rule.”

    The Corps initially concluded that it had no jurisdiction over the site because it contained no “wetlands,” or areas which support “vegetation typically adapted for life in saturated soil conditions,” 33 CFR § 328.3(b) (1999). However, after the Illinois Nature Preserves Commission informed the Corps that a number of migratory bird species had been observed at the site, the Corps reconsidered and ultimately asserted jurisdiction over the balefill site pursuant to subpart (b) of the “Migratory Bird Rule.” The Corps found that approximately 121 bird species had been observed at the site, including several known to depend upon aquatic environments for a significant portion of their life requirements. Thus, on November 16, 1987, the Corps formally “determined that the seasonally ponded, abandoned gravel mining depressions located on the project site, while not wetlands, did qualify as ‘waters of the United States’ … based upon the following criteria: (1) the proposed site had been abandoned as a gravel mining operation; (2) the water areas and spoil piles had developed a natural character; and (3) the water areas are used as habitat by migratory bird [sic] which cross state lines.” U.S. Army Corps of Engineers, Chicago District, Dept. of Army Permit Evaluation and Decision Document, Lodging of Petitioner, Tab No. 1, p. 6.
    ....

    Petitioner filed suit under the Administrative Procedure Act, 5 U.S.C. § 701 et seq., in the Northern District of Illinois challenging both the Corps’ jurisdiction over the site and the merits of its denial of the §404(a) permit. The District Court granted summary judgment to respondents on the jurisdictional issue, and petitioner abandoned its challenge to the Corps’ permit decision. On appeal to the Court of Appeals for the Seventh Circuit, petitioner renewed its attack on respondents’ use of the “Migratory Bird Rule” to assert jurisdiction over the site. Petitioner argued that respondents had exceeded their statutory authority in interpreting the CWA to cover nonnavigable, isolated, intrastate waters based upon the presence of migratory birds and, in the alternative, that Congress lacked the power under the Commerce Clause to grant such regulatory jurisdiction.

    The Court of Appeals began its analysis with the constitutional question, holding that Congress has the authority to regulate such waters based upon “the cumulative impact doctrine, under which a single activity that itself has no discernible effect on interstate commerce may still be regulated if the aggregate effect of that class of activity has a substantial impact on interstate commerce.” 191 F.3d 845, 850 (CA7 1999). The aggregate effect of the “destruction of the natural habitat of migratory birds” on interstate commerce, the court held, was substantial because each year millions of Americans cross state lines and spend over a billion dollars to hunt and observe migratory birds. Ibid. The Court of Appeals then turned to the regulatory question. The court held that the CWA reaches as many waters as the Commerce Clause allows and, given its earlier Commerce Clause ruling, it therefore followed that respondents’ “Migratory Bird Rule” was a reasonable interpretation of the Act. See id., at 851—852.

    We granted certiorari, 529 U.S. 1129 (2000), and now reverse.

    Congress passed the CWA for the stated purpose of “restor[ing] and maintain[ing] the chemical, physical, and biological integrity of the Nation’s waters.” 33 U.S.C. § 1251(a). In so doing, Congress chose to “recognize, preserve, and protect the primary responsibilities and rights of States to prevent, reduce, and eliminate pollution, to plan the development and use (including restoration, preservation, and enhancement) of land and water resources, and to consult with the Administrator in the exercise of his authority under this chapter.” §1251(b). Relevant here, §404(a) authorizes respondents to regulate the discharge of fill material into “navigable waters,” 33 U.S.C. § 1344(a), which the statute defines as “the waters of the United States, including the territorial seas,” §1362(7). Respondents have interpreted these words to cover the abandoned gravel pit at issue here because it is used as habitat for migratory birds. We conclude that the “Migratory Bird Rule” is not fairly supported by the CWA.

    This is not the first time we have been called upon to evaluate the meaning of §404(a). In United States v. Riverside Bayview Homes, Inc., 474 U.S. 121 (1985), we held that the Corps had §404(a) jurisdiction over wetlands that actually abutted on a navigable waterway. In so doing, we noted that the term “navigable” is of “limited import” and that Congress evidenced its intent to “regulate at least some waters that would not be deemed ‘navigable’ under the classical understanding of that term.” Id., at 133. But our holding was based in large measure upon Congress’ unequivocal acquiescence to, and approval of, the Corps’ regulations interpreting the CWA to cover wetlands adjacent to navigable waters. See id., at 135—139. We found that Congress’ concern for the protection of water quality and aquatic ecosystems indicated its intent to regulate wetlands “inseparably bound up with the ‘waters’ of the United States.” Id., at 134.

    It was the significant nexus between the wetlands and “navigable waters” that informed our reading of the CWA in Riverside Bayview Homes. Indeed, we did not “express any opinion” on the “question of the authority of the Corps to regulate discharges of fill material into wetlands that are not adjacent to bodies of open water … .” Id., at 131—132, n. 8. In order to rule for respondents here, we would have to hold that the jurisdiction of the Corps extends to ponds that are not adjacent to open water. But we conclude that the text of the statute will not allow this.

    Indeed, the Corps’ original interpretation of the CWA, promulgated two years after its enactment, is inconsistent with that which it espouses here. Its 1974 regulations defined §404(a)’s “navigable waters” to mean “those waters of the United States which are subject to the ebb and flow of the tide, and/or are presently, or have been in the past, or may be in the future susceptible for use for purposes of interstate or foreign commerce.” 33 CFR § 209.120(d)(1). The Corps emphasized that “[i]t is the water body’s capability of use by the public for purposes of transportation or commerce which is the determinative factor.” §209.260(e)(1). Respondents put forward no persuasive evidence that the Corps mistook Congress’ intent in 1974.

    Respondents next contend that whatever its original aim in 1972, Congress charted a new course five years later when it approved the more expansive definition of “navigable waters” found in the Corps’ 1977 regulations. In July 1977, the Corps formally adopted 33 CFR § 323.2(a)(5) (1978), which defined “waters of the United States” to include “isolated wetlands and lakes, intermittent streams, prairie potholes, and other waters that are not part of a tributary system to interstate waters or to navigable waters of the United States, the degradation or destruction of which could affect interstate commerce.” Respondents argue that Congress was aware of this more expansive interpretation during its 1977 amendments to the CWA. Specifically, respondents point to a failed House bill, H. R. 3199, that would have defined “navigable waters” as “all waters which are presently used, or are susceptible to use in their natural condition or by reasonable improvement as a means to transport interstate or foreign commerce.” 123 Cong. Rec. 10420, 10434 (1977). They also point to the passage in §404(g)(1) that authorizes a State to apply to the Environmental Protection Agency for permission “to administer its own individual and general permit program for the discharge of dredged or fill material into the navigable waters (other than those waters which are presently used, or are susceptible to use in their natural condition or by reasonable improvement as a means to transport interstate or foreign commerce … including wetlands adjacent thereto) within its jurisdiction … .” 33 U.S.C. § 1344(g)(1). The failure to pass legislation that would have overturned the Corps’ 1977 regulations and the extension of jurisdiction in §404(g) to waters “other than” traditional “navigable waters,” respondents submit, indicate that Congress recognized and accepted a broad definition of “navigable waters” that includes nonnavigable, isolated, intrastate waters.

    Although we have recognized congressional acquiescence to administrative interpretations of a statute in some situations, we have done so with extreme care. “[F]ailed legislative proposals are ‘a particularly dangerous ground on which to rest an interpretation of a prior statute.’” Central Bank of Denver, N. A. v. First Interstate Bank of Denver, N. A., 511 U.S. 164, 187 (1994) (quoting Pension Benefit Guaranty Corporation v. LTV Corp., 496 U.S. 633, 650 (1990)). A bill can be proposed for any number of reasons, and it can be rejected for just as many others. The relationship between the actions and inactions of the 95th Congress and the intent of the 92d Congress in passing §404(a) is also considerably attenuated. Because “subsequent history is less illuminating than the contemporaneous evidence,” Hagen v. Utah, 510 U.S. 399, 420 (1994), respondents face a difficult task in overcoming the plain text and import of §404(a).

    We conclude that respondents have failed to make the necessary showing that the failure of the 1977 House bill demonstrates Congress’ acquiescence to the Corps’ regulations or the “Migratory Bird Rule,” which, of course, did not first appear until 1986. Although respondents cite some legislative history showing Congress’ recognition of the Corps’ assertion of jurisdiction over “isolated waters,” as we explained in Riverside Bayview Homes, “[i]n both Chambers, debate on the proposals to narrow the definition of navigable waters centered largely on the issue of wetlands preservation.” 474 U.S., at 136. Beyond Congress’ desire to regulate wetlands adjacent to “navigable waters,” respondents point us to no persuasive evidence that the House bill was proposed in response to the Corps’ claim of jurisdiction over nonnavigable, isolated, intrastate waters or that its failure indicated congressional acquiescence to such jurisdiction.
  ....

    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 statute to push the limit of congressional authority. See ibid. This concern is heightened where the administrative interpretation alters the federal-state framework by permitting federal encroachment upon a traditional state power. See United States v. Bass, 404 U.S. 336, 349 (1971) (“[U]nless Congress conveys its purpose clearly, it will not be deemed to have significantly changed the federal-state balance”). Thus, “where an otherwise acceptable construction of a statute would raise serious constitutional problems, the Court will construe the statute to avoid such problems unless such construction is plainly contrary to the intent of Congress.” DeBartolo, supra, at 575.

 
    We hold that 33 CFR § 328.3(a)(3) (1999), as clarified and applied to petitioner’s balefill site pursuant to the “Migratory Bird Rule,” 51 Fed. Reg. 41217 (1986), exceeds the authority granted to respondents under §404(a) of the CWA. The judgment of the Court of Appeals for the Seventh Circuit is therefore

Reversed.

    Justice Stevens, with whom Justice Souter, Justice Ginsburg, and Justice Breyer join, dissenting.

    In 1969, the Cuyahoga River in Cleveland, Ohio, coated with a slick of industrial waste, caught fire. Congress responded to that dramatic event, and to others like it, by enacting the Federal Water Pollution Control Act (FWPCA) Amendments of 1972, 86 Stat. 817, as amended 33 U.S.C. § 1251 et seq., commonly known as the Clean Water Act (Clean Water Act, CWA, or Act). The Act proclaimed the ambitious goal of ending water pollution by 1985. §1251(a). The Court’s past interpretations of the CWA have been fully consistent with that goal. Although Congress’ vision of zero pollution remains unfulfilled, its pursuit has unquestionably retarded the destruction of the aquatic environment. Our Nation’s waters no longer burn. Today, however, the Court takes an unfortunate step that needlessly weakens our principal safeguard against toxic water.

    It is fair to characterize the Clean Water Act as “watershed” legislation. The statute endorsed fundamental changes in both the purpose and the scope of federal regulation of the Nation’s waters. In §13 of the Rivers and Harbors Appropriation Act of 1899 (RHA), 30 Stat. 1152, as amended, 33 U.S.C. § 407 Congress had assigned to the Army Corps of Engineers (Corps) the mission of regulating discharges into certain waters in order to protect their use as highways for the transportation of interstate and foreign commerce; the scope of the Corps’ jurisdiction under the RHA accordingly extended only to waters that were “navigable.” In the CWA, however, Congress broadened the Corps’ mission to include the purpose of protecting the quality of our Nation’s waters for esthetic, health, recreational, and environmental uses. The scope of its jurisdiction was therefore redefined to encompass all of “the waters of the United States, including the territorial seas.” §1362(7). That definition requires neither actual nor potential navigability.

    The Court has previously held that the Corps’ broadened jurisdiction under the CWA properly included an 80- acre parcel of low-lying marshy land that was not itself navigable, directly adjacent to navigable water, or even hydrologically connected to navigable water, but which was part of a larger area, characterized by poor drainage, that ultimately abutted a navigable creek. United States v. Riverside Bayview Homes, Inc., 474 U.S. 121 (1985). Our broad finding in Riverside Bayview that the 1977 Congress had acquiesced in the Corps’ understanding of its jurisdiction applies equally to the 410-acre parcel at issue here. Moreover, once Congress crossed the legal watershed that separates navigable streams of commerce from marshes and inland lakes, there is no principled reason for limiting the statute’s protection to those waters or wetlands that happen to lie near a navigable stream.

    In its decision today, the Court draws a new jurisdictional line, one that invalidates the 1986 migratory bird regulation as well as the Corps’ assertion of jurisdiction over all waters except for actually navigable waters, their tributaries, and wetlands adjacent to each. Its holding rests on two equally untenable premises: (1) that when Congress passed the 1972 CWA, it did not intend “to exert anything more than its commerce power over navigation,” ante, at 7, n. 3; and (2) that in 1972 Congress drew the boundary defining the Corps’ jurisdiction at the odd line on which the Court today settles.

    As I shall explain, the text of the 1972 amendments affords no support for the Court’s holding, and amendments Congress adopted in 1977 do support the Corps’ present interpretation of its mission as extending to so-called “isolated” waters. Indeed, simple common sense cuts against the particular definition of the Corps’ jurisdiction favored by the majority.

    The significance of the FWPCA Amendments of 1972 is illuminated by a reference to the history of federal water regulation, a history that the majority largely ignores. Federal regulation of the Nation’s waters began in the 19th century with efforts targeted exclusively at “promot[ing] water transportation and commerce.” Kalen, Commerce to Conservation: The Call for a National Water Policy and the Evolution of Federal Jurisdiction Over Wetlands, 69 N. D. L. Rev. 873, 877 (1993). This goal was pursued through the various Rivers and Harbors Acts, the most comprehensive of which was the RHA of 1899. Section 13 of the 1899 RHA, commonly known as the Refuse Act, prohibited the discharge of “refuse” into any “navigable water” or its tributaries, as well as the deposit of “refuse” on the bank of a navigable water “whereby navigation shall or may be impeded or obstructed” without first obtaining a permit from the Secretary of the Army. 30 Stat. 1152.

    During the middle of the 20th century, the goals of federal water regulation began to shift away from an exclusive focus on protecting navigability and toward a concern for preventing environmental degradation. Kalen, 69 N. D. L. Rev., at 877—879, and n. 30. This awakening of interest in the use of federal power to protect the aquatic environment was helped along by efforts to reinterpret §13 of the RHA in order to apply its permit requirement to industrial discharges into navigable waters, even when such discharges did nothing to impede navigability. See, e.g., United States v. Republic Steel Corp., 362 U.S. 482, 490—491 (1960) (noting that the term “refuse” in §13 was broad enough to include industrial waste). Seeds of this nascent concern with pollution control can also be found in the FWPCA, which was first enacted in 1948 and then incrementally expanded in the following years.

    The shift in the focus of federal water regulation from protecting navigability toward environmental protection reached a dramatic climax in 1972, with the passage of the CWA. The Act, which was passed as an amendment to the existing FWPCA, was universally described by its supporters as the first truly comprehensive federal water pollution legislation. The “major purpose” of the CWA was “to establish a comprehensive long-range policy for the elimination of water pollution.” S. Rep. No. 92—414, p. 95 (1971), reprinted in 2 Legislative History of the Water Pollution Control Act Amendments of 1972 (Committee Print compiled for the Senate Committee on Public Works by the Library of Congress), Ser. No. 93—1, p. 1511 (1971) (hereinafter Leg. Hist.) (emphasis added). And “[n]o Congressman’s remarks on the legislation were complete without reference to [its] ‘comprehensive’ nature … .” Milwaukee v. Illinois, 451 U.S. 304, 318 (1981) (Rehnquist, J.). A House sponsor described the bill as “the most comprehensive and far-reaching water pollution bill we have ever drafted,” 1 Leg. Hist. 369 (Rep. Mizell), and Senator Randolph, Chairman of the Committee on Public Works, stated: “It is perhaps the most comprehensive legislation that the Congress of the United States has ever developed in this particular field of the environment.” 2 id., at 1269. This Court was therefore undoubtedly correct when it described the 1972 amendments as establishing “a comprehensive program for controlling and abating water pollution.” Train v. City of New York, 420 U.S. 35, 37 (1975).

    Section 404 of the CWA resembles §13 of the RHA, but, unlike the earlier statute, the primary purpose of which is the maintenance of navigability, §404 was principally intended as a pollution control measure. A comparison of the contents of the RHA and the 1972 Act vividly illustrates the fundamental difference between the purposes of the two provisions....

    The 1972 Act, in contrast, appropriated large sums of money for research and related programs for water pollution control, 86 Stat. 816—833, and for the construction of water treatment works, id., at 833—844. Strikingly absent from its declaration of “goals and policy” is any reference to avoiding or removing obstructions to navigation. Instead, the principal objective of the Act, as stated by Congress in §101, was “to restore and maintain the chemical, physical, and biological integrity of the Nation’s waters.” 33 U.S.C. § 1251. Congress therefore directed federal agencies in §102 to “develop comprehensive programs for preventing, reducing, or eliminating the pollution of the navigable waters and ground waters and improving the sanitary condition of surface and underground waters.” 33 U.S.C. § 1252. The CWA commands federal agencies to give “due regard,” not to the interest of unobstructed navigation, but rather to “improvements which are necessary to conserve such waters for the protection and propagation of fish and aquatic life and wildlife [and] recreational purposes.” Ibid.

       As we recognized in Riverside Bayview, the interests served by the statute embrace the protection of “‘significant natural biological functions, including food chain production, general habitat, and nesting, spawning, rearing and resting sites’” for various species of aquatic wildlife. 474 U.S., at 134—135. For wetlands and “isolated” inland lakes, that interest is equally powerful, regardless of the proximity of the swamp or the water to a navigable stream. Nothing in the text, the stated purposes, or the legislative history of the CWA supports the conclusion that in 1972 Congress contemplated–much less commanded–the odd jurisdictional line that the Court has drawn today.
....

    As the majority correctly notes, ante, at 7, when the Corps first promulgated regulations pursuant to §404 of the 1972 Act, it construed its authority as being essentially the same as it had been under the 1899 RHA. The reaction to those regulations in the federal courts, in the Environmental Protection Agency (EPA),  and in Congress, convinced the Corps that the statute required it “to protect water quality to the full extent of the [C]ommerce [C]lause” and to extend federal regulation over discharges “to many areas that have never before been subject to Federal permits or to this form of water quality protection.” 40 Fed. Reg. 31320 (1975).
    ....

    The Corps’ broadened reading of its jurisdiction provoked opposition among some Members of Congress. As a result, in 1977, Congress considered a proposal that would have limited the Corps’ jurisdiction under §404 to waters that are used, or by reasonable improvement could be used, as a means to transport interstate or foreign commerce and their adjacent wetlands. H. R. 3199, 95th Cong., 1st Sess., §16(f) (1977). A bill embodying that proposal passed the House but was defeated in the Senate. The debates demonstrate that Congress was fully aware of the Corps’ understanding of the scope of its jurisdiction under the 1972 Act.

.....

    Even if the majority were correct that Congress did not extend the Corps’ jurisdiction in the 1972 CWA to reach beyond navigable waters and their nonnavigable tributaries, Congress’ rejection of the House’s efforts in 1977 to cut back on the Corps’ 1975 assertion of jurisdiction clearly indicates congressional acquiescence in that assertion. Indeed, our broad determination in Riverside Bayview that the 1977 Congress acquiesced in the very regulations at issue in this case should foreclose petitioner’s present urgings to the contrary. The majority’s refusal in today’s decision to acknowledge the scope of our prior decision is troubling.....

    More important than the 1977 bill that did not become law are the provisions that actually were included in the 1977 revisions. Instead of agreeing with those who sought to withdraw the Corps’ jurisdiction over “isolated” waters, Congress opted to exempt several classes of such waters from federal control. §67, 91 Stat. 1601, 33 U.S.C. § 1344(f). For example, the 1977 amendments expressly exclude from the Corps’ regulatory power the discharge of fill material “for the purpose of construction or maintenance of farm or stock ponds or irrigation ditches, or the maintenance of drainage ditches,” and “for the purpose of construction of temporary sedimentation basins on a construction site which does not include placement of fill material into the navigable waters.” Ibid. The specific exemption of these waters from the Corps’ jurisdiction indicates that the 1977 Congress recognized that similarly “isolated” waters not covered by the exceptions would fall within the statute’s outer limits. ...

     Although it might have appeared problematic on a “linguistic” level for the Corps to classify “lands” as “waters” in Riverside Bayview, 474 U.S., at 131—132, we squarely held that the agency’s construction of the statute that it was charged with enforcing was entitled to deference under Chevron U.S. A. Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837 (1984). Today, however, the majority refuses to extend such deference to the same agency’s construction of the same statute, see ante, at 11—13. This refusal is unfaithful to both Riverside Bayview and Chevron. For it is the majority’s reading, not the agency’s, that does violence to the scheme Congress chose to put into place.

    Contrary to the Court’s suggestion, the Corps’ interpretation of the statute does not “encroac[h]” upon “traditional state power” over land use. Ante, at 12. “Land use planning in essence chooses particular uses for the land; environmental regulation, at its core, does not mandate particular uses of the land but requires only that, however the land is used, damage to the environment is kept within prescribed limits.” California Coastal Comm’n v. Granite Rock Co., 480 U.S. 572, 587 (1987). The CWA is not a land-use code; it is a paradigm of environmental regulation. Such regulation is an accepted exercise of federal power. Hodel v. Virginia Surface Mining & Reclamation Assn., Inc., 452 U.S. 264, 282 (1981).

    It is particularly ironic for the Court to raise the specter of federalism while construing a statute that makes explicit efforts to foster local control over water regulation. Faced with calls to cut back on federal jurisdiction over water pollution, Congress rejected attempts to narrow the scope of that jurisdiction and, by incorporating §404(g), opted instead for a scheme that encouraged States to supplant federal control with their own regulatory programs. S. Rep. No. 95—370, at 75, reprinted in 4 Leg. Hist. of CWA 708 (“The committee amendment does not redefine navigable waters. Instead, the committee amendment intends to assure continued protection of all the Nation’s waters, but allows States to assume the primary responsibility for protecting those lakes, rivers, streams, swamps, marshes, and other portions of the navigable waters outside the [C]orps program in the so-called phase I waters” (emphasis added)). Because Illinois could have taken advantage of the opportunities offered to it through §404(g), the federalism concerns to which the majority adverts are misplaced.     The Corps’ interpretation of the statute as extending beyond navigable waters, tributaries of navigable waters, and wetlands adjacent to each is manifestly reasonable and therefore entitled to deference.

    Because I am convinced that the Court’s miserly construction of the statute is incorrect, I shall comment briefly on petitioner’s argument that Congress is without power to prohibit it from filling any part of the 31 acres of ponds on its property in Cook County, Illinois. The Corps’ exercise of its §404 permitting power over “isolated” waters that serve as habitat for migratory birds falls well within the boundaries set by this Court’s Commerce Clause jurisprudence.

    In United States v. Lopez, 514 U.S. 549, 558—559 (1995), this Court identified “three broad categories of activity that Congress may regulate under its commerce power”: (1) channels of interstate commerce; (2) instrumentalities of interstate commerce, or persons and things in interstate commerce; and (3) activities that “substantially affect” interstate commerce. Ibid. The migratory bird rule at issue here is properly analyzed under the third category. In order to constitute a proper exercise of Congress’ power over intrastate activities that “substantially affect” interstate commerce, it is not necessary that each individual instance of the activity substantially affect commerce; it is enough that, taken in the aggregate, the class of activities in question has such an effect. Perez v. United States, 402 U.S. 146 (1971) ...

    The activity being regulated in this case (and by the Corps’ §404 regulations in general) is the discharge of fill material into water. The Corps did not assert jurisdiction over petitioner’s land simply because the waters were “used as habitat by migratory birds.” It asserted jurisdiction because petitioner planned to discharge fill into waters “used as habitat by migratory birds.” Had petitioner intended to engage in some other activity besides discharging fill (i.e., had there been no activity to regulate), or, conversely, had the waters not been habitat for migratory birds (i.e., had there been no basis for federal jurisdiction), the Corps would never have become involved in petitioner’s use of its land. ...
....

    In addition to the intrinsic value of migratory birds, see Missouri v. Holland, 252 U.S. 416, 435 (1920) (noting the importance of migratory birds as “protectors of our forests and our crops” and as “a food supply”), it is undisputed that literally millions of people regularly participate in birdwatching and hunting and that those activities generate a host of commercial activities of great value. The causal connection between the filling of wetlands and the decline of commercial activities associated with migratory birds is not “attenuated,” Morrison, 529 U.S., at 612; it is direct and concrete...

      Whether it is necessary or appropriate to refuse to allow petitioner to fill those ponds is a question on which we have no voice. Whether the Federal Government has the power to require such permission, however, is a question that is easily answered. If, as it does, the Commerce Clause empowers Congress to regulate particular “activities causing air or water pollution, or other environmental hazards that may have effects in more than one State,” Hodel, 452 U.S., at 282, it also empowers Congress to control individual actions that, in the aggregate, would have the same effect. Perez, 402 U.S., at 154; Wickard, 317 U.S., at 127—128. There is no merit in petitioner’s constitutional argument.

    Because I would affirm the judgment of the Court of Appeals, I respectfully dissent.