SOLID WASTE AGENCY OF NORTHERN COOK COUNTY v. UNITED STATES ARMY CORPS OF ENGINEERS et al.

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159 OCTOBER TERM, 2000
Syllabus
SOLID WASTE AGENCY OF NORTHERN COOK
COUNTY v. UNITED STATES ARMY CORPS
OF ENGINEERS et al.
certiorari to the united states court of appeals for
the seventh circuit
No. 99–1178. Argued October 31, 2000—Decided January 9, 2001
Petitioner, a consortium of suburban Chicago municipalities, selected as a
solid waste disposal site an abandoned sand and gravel pit with excava-
tion trenches that had evolved into permanent and seasonal ponds. Be-
cause the operation called for filling in some of the ponds, petitioner
contacted federal respondents, including the Army Corps of Engineers
(Corps), to determine if a landfill permit was required under § 404(a) of
the Clean Water Act (CWA), which authorizes the Corps to issue per-
mits allowing the discharge of dredged or fill material into “navigable
waters.” The CWA defines “navigable waters” as “the waters of the
United States,” 33 U. S. C. § 1362(7), and the Corps’ regulations define
such waters to include intrastate waters, “the use, degradation or de-
struction of which could affect interstate or foreign commerce,” 33 CFR
§ 328.3(a)(3). In 1986, the Corps attempted to clarify its jurisdiction,
stating, in what has been dubbed the “Migratory Bird Rule,” that
§ 404(a) extends to intrastate waters that, inter alia, provide habitat for
migratory birds. 51 Fed. Reg. 41217. Asserting jurisdiction over the
instant site pursuant to that Rule, the Corps refused to issue a § 404(a)
permit. When petitioner challenged the Corps’ jurisdiction and the
merits of the permit denial, the District Court granted respondents
summary judgment on the jurisdictional issue. The Seventh Circuit
held that Congress has authority under the Commerce Clause to regu-
late intrastate waters and that the Migratory Bird Rule is a reasonable
interpretation of the CWA.
Held: Title 33 CFR § 328.3(a)(3), as clarified and applied to petitioner’s
site pursuant to the Migratory Bird Rule, exceeds the authority granted
to respondents under § 404(a) of the CWA. Pp. 166–174.
(a) In United States v. Riverside Bayview Homes, Inc., 474 U. S. 121,
this Court held that the Corps had § 404(a) jurisdiction over wetlands
adjacent to a navigable waterway, noting 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 [that
term’s] classical understanding,” id., at 133. But that holding was
based in large measure upon Congress’ unequivocal acquiescence to, and

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160 SOLID WASTE AGENCY OF NORTHERN COOK CTY.
v. ARMY CORPS OF ENGINEERS
Syllabus
approval of, the Corps’ regulations interpreting the CWA to cover wet-
lands adjacent to navigable waters. See id., at 135–139. The Court
expressed no opinion on the question of the Corps’ authority to reg-
ulate wetlands not adjacent to open water, and the statute’s text will
not allow extension of the Corps’ jurisdiction to such wetlands here.
Pp. 166–168.
(b) The Corps’ original interpretation of the CWA in its 1974 regula-
tions—which emphasized that a water body’s capability of use by the
public for transportation or commerce determines whether it is naviga-
ble—is inconsistent with that which it espouses here, yet respondents
present no persuasive evidence that the Corps mistook Congress’ intent
in 1974. Respondents contend that whatever its original aim, when
Congress amended the CWA in 1977, it approved the more expansive
definition of “navigable waters” found in the Corps’ 1977 regulations.
Specifically, respondents submit that Congress’ failure to pass legisla-
tion that would have overturned the 1977 regulations and the extension
of the Environmental Protection Agency’s jurisdiction in § 404(g) to in-
clude waters “other than” traditional “navigable waters” indicates that
Congress recognized and accepted a broad definition of “navigable
waters” that includes nonnavigable, isolated, intrastate waters. This
Court recognizes congressional acquiescence to administrative interpre-
tations of a statute with extreme care. Failed 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, because a bill can be proposed or
rejected for any number of reasons. Here, respondents have failed to
make the necessary showing that Congress’ failure to pass legislation
demonstrates acquiescence to the 1977 regulations or the 1986 Migra-
tory Bird Rule. Section 404(g) is equally unenlightening, for it does
not conclusively determine the construction to be placed on the use of
the term “waters” elsewhere in the CWA. Riverside Bayview Homes,
supra, at 138, n. 11. Pp. 168–172.
(c) Even if § 404(a) were not clear, this Court would not extend defer-
ence to the Migratory Bird Rule under Chevron U. S. A. Inc. v. Natural
Resources Defense Council, Inc., 467 U. S. 837. Where an adminis-
trative interpretation of a statute would raise serious constitutional
problems, the Court will construe the statute to avoid such problems
unless the construction is plainly contrary to Congress’ intent. Edward
J. DeBartolo Corp. v. Florida Gulf Coast Building & Constr. Trades
Council, 485 U. S. 568, 575. The grant of authority to Congress under
the Commerce Clause, though broad, is not unlimited. See, e. g., United
States v. Morrison, 529 U. S. 598. Respondents’ arguments, e. g., that
the Migratory Bird Rule falls within Congress’ power to regulate intra-

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161 Cite as: 531 U. S. 159 (2001)
Syllabus
state activities that substantially affect interstate commerce, raise sig-
nificant constitutional questions, yet there is nothing approaching a
clear statement from Congress that it intended § 404(a) to reach an aban-
doned sand and gravel pit such as the one at issue. Permitting respond-
ents to claim federal jurisdiction over ponds and mudflats falling within
the Migratory Bird Rule would also result in a significant impingement
of the States’ traditional and primary power over land and water use.
The Court thus reads the statute as written to avoid such significant
constitutional and federalism questions and rejects the request for ad-
ministrative deference. Pp. 172–174.
191 F. 3d 845, reversed.
Rehnquist, C. J., delivered the opinion of the Court, in which O’Con-
nor, Scalia, Kennedy, and Thomas, JJ., joined. Stevens, J., filed a
dissenting opinion, in which Souter, Ginsburg, and Breyer, JJ., joined,
post, p. 174.
Timothy S. Bishop argued the cause for petitioner. With
him on the briefs were Kaspar J. Stoffelmayr, Sharon
Swingle, and George J. Mannina, Jr.
Deputy Solicitor General Wallace argued the cause for
respondents. With him on the brief for the federal respond-
ents were Solicitor General Waxman, Assistant Attorney
General Schiffer, Malcolm L. Stewart, and John A. Bryson.
Myron M. Cherry filed a brief for respondents Village of
Bartlett et al.*
*Briefs of amici curiae urging reversal were filed for the State of Ala-
bama by Bill Pryor, Attorney General, Alice Ann Byrne, Assistant Attor-
ney General, and Jeffrey S. Sutton; for the American Farm Bureau Feder-
ation et al. by William G. Myers III; for Arid Operations, Inc., by Charles
L. Kaiser; for Cargill, Inc., by Leslie G. Landau, Edgar B. Washburn, and
David M. Ivester; for the Cato Institute et al. by Theodore M. Cooperstein,
William H. Mellor, Clint Bolick, Scott G. Bullock, Timothy Lynch, Rob-
ert A. Levy, and Ronald D. Rotunda; for the Center for the Original In-
tent of the Constitution by Michael P. Farris and Scott W. Somerville; for
the Chamber of Commerce of the United States by Robert R. Gasaway,
Jeffrey B. Clark, Daryl Joseffer, and Robin S. Conrad; for the Claremont
Institute Center for Constitutional Jurisprudence by Edwin Meese III; for
Defenders of Property Rights by Nancie G. Marzulla; for the National
Association of Home Builders by Thomas C. Jackson; for the Nationwide

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162 SOLID WASTE AGENCY OF NORTHERN COOK CTY.
v. ARMY CORPS OF ENGINEERS
Opinion of the Court
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 dis-
charge 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 pro-
vides 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
Public Projects Coalition et al. by Lawrence R. Liebesman; for the Pacific
Legal Foundation et al. by Anne M. Hayes and M. Reed Hopper; for the
Serrano Water District et al. by Virginia S. Albrecht and Stephen J.
Wenderoth; for the Washington Legal Foundation et al. by Mark A. Perry,
Daniel J. Popeo, and Paul D. Kamenar; for the U. S. Conference of Mayors
et al. by Richard Ruda and James I. Crowley; and for James J. Wilson by
Steven A. Steinbach and Gerald A. Feffer.
Briefs of amici curiae urging affirmance were filed for the State of
California et al. by Bill Lockyer, Attorney General of California, Richard
M. Frank, Chief Assistant Attorney General, J. Matthew Rodriguez, Se-
nior Assistant Attorney General, Dennis M. Eagan, Supervising Deputy
Attorney General, and Joseph Barbieri, Deputy Attorney General, and by
the Attorneys General for their respective States as follows: Thomas J.
Miller of Iowa, Andrew Ketterer of Maine, John J. Farmer, Jr., of New
Jersey, W. A. Drew Edmondson of Oklahoma, Hardy Myers of Oregon,
William H. Sorrell of Vermont, and Christine O. Gregoire of Washington;
for the Anti-Defamation League et al. by Martin E. Karlinsky, Steven M.
Freeman, Michael Lieberman, and Elliot M. Mincberg; and for Environ-
mental Defense et al. by Louis R. Cohen and Michael Bean.
Briefs of amici curiae were filed for the American Forest & Paper Asso-
ciation et al. by Russell S. Frye; for the Center for Individual Rights by
Michael E. Rosman; for the National Stone Association by Kurt E. Blase;
and for Dr. Gene Likens et al. by Michael Bean.

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163 Cite as: 531 U. S. 159 (2001)
Opinion of the Court
cities and villages that united in an effort to locate and de-
velop 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 re-
spondents), 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 naviga-
ble 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 (includ-
ing 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).

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164 SOLID WASTE AGENCY OF NORTHERN COOK CTY.
v. ARMY CORPS OF ENGINEERS
Opinion of the Court
In 1986, in an attempt to “clarify” the reach of its jurisdic-
tion, 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 endan-
gered 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.” 1
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 satu-
rated 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 ob-
served at the site, the Corps reconsidered and ultimately as-
serted jurisdiction over the balefill site pursuant to subpart
(b) of the “Migratory Bird Rule.” The Corps found that ap-
proximately 121 bird species had been observed at the site,
including several known to depend upon aquatic environ-
ments for a significant portion of their life requirements.
Thus, on November 16, 1987, the Corps formally “determined
that the seasonally ponded, abandoned gravel mining depres-
sions located on the project site, while not wetlands, did qual-
ify as ‘waters of the United States’ . . . based upon the follow-
ing 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
1 The Corps issued the “Migratory Bird Rule” without following the no-
tice and comment procedures outlined in the Administrative Procedure
Act, 5 U. S. C. § 553.

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Opinion of the Court
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.
During the application process, SWANCC made several
proposals to mitigate the likely displacement of the migra-
tory birds and to preserve a great blue heron rookery located
on the site. Its balefill project ultimately received the nec-
essary local and state approval. By 1993, SWANCC had re-
ceived a special use planned development permit from the
Cook County Board of Appeals, a landfill development per-
mit from the Illinois Environmental Protection Agency, and
approval from the Illinois Department of Conservation.
Despite SWANCC’s securing the required water qual-
ity certification from the Illinois Environmental Protection
Agency, the Corps refused to issue a § 404(a) permit. The
Corps found that SWANCC had not established that its pro-
posal was the “least environmentally damaging, most practi-
cable alternative” for disposal of nonhazardous solid waste;
that SWANCC’s failure to set aside sufficient funds to reme-
diate leaks posed an “unacceptable risk to the public’s drink-
ing water supply”; and that the impact of the project upon
area-sensitive species was “unmitigatable since a landfill sur-
face cannot be redeveloped into a forested habitat.” Id.,
at 87.
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 ju-
risdictional issue, and petitioner abandoned its challenge to
the Corps’ permit decision. On appeal to the Court of Ap-
peals 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 respond-
ents had exceeded their statutory authority in interpreting

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166 SOLID WASTE AGENCY OF NORTHERN COOK CTY.
v. ARMY CORPS OF ENGINEERS
Opinion of the Court
the CWA to cover nonnavigable, isolated, intrastate waters
based upon the presence of migratory birds and, in the alter-
native, that Congress lacked the power under the Commerce
Clause to grant such regulatory jurisdiction.
The Court of Appeals began its analysis with the constitu-
tional 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 dis-
cernible effect on interstate commerce may still be regulated
if the aggregate effect of that class of activity has a substan-
tial 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.2 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, pre-
serve, and protect the primary responsibilities and rights of
2 Relying upon its earlier decision in Hoffman Homes, Inc. v. EPA, 999
F. 2d 256 (CA7 1993), and a report from the United States Census Bureau,
the Court of Appeals found that in 1996 approximately 3.1 million Ameri-
cans spent $1.3 billion to hunt migratory birds (with 11 percent crossing
state lines to do so) as another 17.7 million Americans observed migratory
birds (with 9.5 million traveling for the purpose of observing shorebirds).
See 191 F. 3d, at 850.

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States to prevent, reduce, and eliminate pollution, to plan
the development and use (including restoration, preserva-
tion, and enhancement) of land and water resources, and to
consult with the Administrator in the exercise of his author-
ity under this chapter.” § 1251(b). Relevant here, § 404(a)
authorizes respondents to regulate the discharge of fill mate-
rial 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 inter-
preted 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 sup-
ported by the CWA.
This is not the first time we have been called upon to eval-
uate 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 wa-
ters 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 ac-
quiescence to, and approval of, the Corps’ regulations inter-
preting the CWA to cover wetlands adjacent to navigable
waters. See id., at 135–139. We found that Congress’ con-
cern for the protection of water quality and aquatic ecosys-
tems 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,

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168 SOLID WASTE AGENCY OF NORTHERN COOK CTY.
v. ARMY CORPS OF ENGINEERS
Opinion of the Court
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 de-
fined § 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 inter-
state 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). Re-
spondents put forward no persuasive evidence that the
Corps mistook Congress’ intent in 1974.3
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 wa-
ters” 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
3 Respondents refer us to portions of the legislative history that they
believe indicate Congress’ intent to expand the definition of “navigable
waters.” Although the Conference Report includes the statement that
the conferees “intend that the term ‘navigable waters’ be given the broad-
est possible constitutional interpretation,” S. Conf. Rep. No. 92–1236,
p. 144 (1972), neither this, nor anything else in the legislative history to
which respondents point, signifies that Congress intended to exert any-
thing more than its commerce power over navigation. Indeed, respond-
ents admit that the legislative history is somewhat ambiguous. See Brief
for Federal Respondents 24.

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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 de-
fined “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 inter-
state or foreign commerce.” 123 Cong. Rec. 10420, 10434
(1977).4 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, in-
trastate waters.
Although we have recognized congressional acquiescence
to administrative interpretations of a statute in some situa-
tions, we have done so with extreme care.5 “[F]ailed legis-
4 While this bill passed in the House, a similarly worded amendment to
a bill originating in the Senate, S. 1952, failed. See 123 Cong. Rec. 26710,
26728 (1977).
5 In Bob Jones Univ. v. United States, 461 U. S. 574, 595, 600–601 (1983),
for example, we upheld an Internal Revenue Service (IRS) Revenue Rul-
ing that revoked the tax-exempt status of private schools practicing racial
discrimination because the IRS’ interpretation of the relevant statutes
was “correct”; because Congress had held “hearings on this precise issue,”
making it “hardly conceivable that Congress—and in this setting, any
Member of Congress—was not abundantly aware of what was going on”;

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170 SOLID WASTE AGENCY OF NORTHERN COOK CTY.
v. ARMY CORPS OF ENGINEERS
Opinion of the Court
lative 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 relation-
ship 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 nec-
essary showing that the failure of the 1977 House bill demon-
strates Congress’ acquiescence to the Corps’ regulations or
the “Migratory Bird Rule,” which, of course, did not first
appear until 1986. Although respondents cite some legisla-
tive history showing Congress’ recognition of the Corps’ as-
sertion of jurisdiction over “isolated waters,” 6 as we ex-
plained 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 preserva-
tion.” 474 U. S., at 136. Beyond Congress’ desire to regu-
and because “no fewer than 13 bills introduced to overturn the IRS inter-
pretation” had failed. Absent such overwhelming evidence of acquies-
cence, we are loath to replace the plain text and original understanding of
a statute with an amended agency interpretation. See Consumer Prod-
uct Safety Comm’n v. GTE Sylvania, Inc., 447 U. S. 102, 118, n. 13 (1980)
(“[E]ven when it would otherwise be useful, subsequent legislative history
will rarely override a reasonable interpretation of a statute that can be
gleaned from its language and legislative history prior to its enactment”).
6 Respondents cite, for example, the Senate Report on S. 1952, which
referred to the Corps’ “isolated waters” regulation. See S. Rep. No. 95–
370, p. 75 (1977). However, the same report reiterated that “[t]he com-
mittee amendment does not redefine navigable waters.” Ibid.

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late 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.
Section 404(g) is equally unenlightening. In Riverside
Bayview Homes we recognized that Congress intended the
phrase “navigable waters” to include “at least some waters
that would not be deemed ‘navigable’ under the classical un-
derstanding of that term.” Id., at 133. But § 404(g) gives
no intimation of what those waters might be; it simply refers
to them as “other . . . waters.” Respondents conjecture that
“other . . . waters” must incorporate the Corps’ 1977 regula-
tions, but it is also plausible, as petitioner contends, that
Congress simply wanted to include all waters adjacent to
“navigable waters,” such as nonnavigable tributaries and
streams. The exact meaning of § 404(g) is not before us and
we express no opinion on it, but for present purposes it is
sufficient to say, as we did in Riverside Bayview Homes, that
Ҥ 404(g)(1) does not conclusively determine the construction
to be placed on the use of the term ‘waters’ elsewhere in
the Act (particularly in § 502(7), which contains the relevant
definition of ‘navigable waters’) . . . .” Id., at 138, n. 11.7
We thus decline respondents’ invitation to take what they
see as the next ineluctable step after Riverside Bayview
Homes: holding that isolated ponds, some only seasonal,
wholly located within two Illinois counties, fall under
§ 404(a)’s definition of “navigable waters” because they serve
7 Respondents also make a passing reference to Congress’ decision in
1977 to exempt certain types of discharges from § 404(a), including, for
example, “discharge of dredged or fill material . . . for the purpose of
construction or maintenance of farm or stock ponds or irrigation ditches,
or the maintenance of drainage ditches.” § 67, 91 Stat. 1600, 33 U. S. C.
§ 1344(f)(C). As § 404(a) only regulates dredged or fill material that is
discharged “into navigable waters,” Congress’ decision to exempt certain
types of these discharges does not affect, much less address, the definition
of “navigable waters.”

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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 “naviga-
ble” 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 im-
port of showing us what Congress had in mind as its author-
ity 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 ad-
dressed 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, intra-
state 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 in-
vokes 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 con-
stitutional issues and our assumption that Congress does not
casually authorize administrative agencies to interpret a

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173 Cite as: 531 U. S. 159 (2001)
Opinion of the Court
statute to push the limit of congressional authority. See
ibid. This concern is heightened where the administrative
interpretation alters the federal-state framework by permit-
ting 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 stat-
ute 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.
Twice in the past six years we have reaffirmed the proposi-
tion that the grant of authority to Congress under the Com-
merce Clause, though broad, is not unlimited. See United
States v. Morrison, 529 U. S. 598 (2000); United States v.
Lopez, 514 U. S. 549 (1995). Respondents argue that the
“Migratory Bird Rule” falls within Congress’ power to regu-
late intrastate activities that “substantially affect” interstate
commerce. They note that the protection of migratory birds
is a “national interest of very nearly the first magnitude,”
Missouri v. Holland, 252 U. S. 416, 435 (1920), and that, as
the Court of Appeals found, millions of people spend over a
billion dollars annually on recreational pursuits relating to
migratory birds. These arguments raise significant consti-
tutional questions. For example, we would have to evaluate
the precise object or activity that, in the aggregate, substan-
tially affects interstate commerce. This is not clear, for al-
though the Corps has claimed jurisdiction over petitioner’s
land because it contains water areas used as habitat by mi-
gratory birds, respondents now, post litem motam, focus
upon the fact that the regulated activity is petitioner’s mu-
nicipal landfill, which is “plainly of a commercial nature.”
Brief for Federal Respondents 43. But this is a far cry, in-
deed, from the “navigable waters” and “waters of the United
States” to which the statute by its terms extends.

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174 SOLID WASTE AGENCY OF NORTHERN COOK CTY.
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Stevens, J., dissenting
These are significant constitutional questions raised by re-
spondents’ application of their regulations, and yet we find
nothing approaching a clear statement from Congress that it
intended § 404(a) to reach an abandoned sand and gravel pit
such as we have here. Permitting respondents to claim fed-
eral jurisdiction over ponds and mudflats falling within the
“Migratory Bird Rule” would result in a significant impinge-
ment of the States’ traditional and primary power over land
and water use. See, e. g., Hess v. Port Authority Trans-
Hudson Corporation, 513 U. S. 30, 44 (1994) (“[R]egulation
of land use [is] a function traditionally performed by local
governments”). Rather than expressing a desire to readjust
the federal-state balance in this manner, Congress chose to
“recognize, preserve, and protect the primary responsibil-
ities and rights of States . . . to plan the development and
use . . . of land and water resources . . . .” 33 U. S. C.
§ 1251(b). We thus read the statute as written to avoid the
significant constitutional and federalism questions raised by
respondents’ interpretation, and therefore reject the request
for administrative deference.8
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 re-
8 Because violations of the CWA carry criminal penalties, see 33 U. S. C.
§ 1319(c)(2), petitioner invokes the rule of lenity as another basis for reject-
ing the Corps’ interpretation of the CWA. Brief for Petitioner 31–32.
We need not address this alternative argument. See United States v.
Shabani, 513 U. S. 10, 17 (1994).

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Stevens, J., dissenting
sponded 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).1 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 prin-
cipal safeguard against toxic water.
It is fair to characterize the Clean Water Act as “wa-
tershed” legislation. The statute endorsed fundamental
changes in both the purpose and the scope of federal reg-
ulation 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 regu-
lating 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 broad-
ened the Corps’ mission to include the purpose of protecting
the quality of our Nation’s waters for esthetic, health, rec-
reational, and environmental uses. The scope of its juris-
diction 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 poten-
tial navigability.
The Court has previously held that the Corps’ broadened
jurisdiction under the CWA properly included an 80-acre
1 See R. Adler, J. Landman, & D. Cameron, The Clean Water Act: 20
Years Later 5–10 (1993).

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176 SOLID WASTE AGENCY OF NORTHERN COOK CTY.
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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). 2 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 Con-
gress 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 naviga-
ble 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
2 See also App. to Pet. for Cert. 25a, and Brief for United States 8,
n. 7, in Riverside Bayview, O. T. 1984, No. 84–701. The District Court in
Riverside Bayview found that there was no direct “hydrological” connec-
tion between the parcel at issue and any nearby navigable waters. App.
to Pet. for Cert. in Riverside Bayview 25a. The wetlands characteristics
of the parcel were due, not to a surface or groundwater connection to any
actually navigable water, but to “poor drainage” resulting from “the Lam-
son soil that underlay the property.” Brief for Respondent in Riverside
Bayview 7. Nevertheless, this Court found occasional surface runoff from
the property into nearby waters to constitute a meaningful connection.
Riverside Bayview, 474 U. S., at 134; Brief for United States in Riverside
Bayview 8, n. 7. Of course, the ecological connection between the wet-
lands and the nearby waters also played a central role in this Court’s
decision. Riverside Bayview, 474 U. S., at 134–135. Both types of con-
nection are also present in many, and possibly most, “isolated” waters.
Brief for Dr. Gene Likens et al. as Amici Curiae 6–22. Indeed, although
the majority and petitioner both refer to the waters on petitioner’s site as
“isolated,” ante, at 172; Brief for Petitioner 11, their role as habitat for
migratory birds, birds that serve important functions in the ecosystems
of other waters throughout North America, suggests that—ecologically
speaking—the waters at issue in this case are anything but isolated.

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177 Cite as: 531 U. S. 159 (2001)
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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 com-
merce power over navigation,” ante, at 168, n. 3; and (2) that
in 1972 Congress drew the boundary defining the Corps’ ju-
risdiction 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 Con-
gress adopted in 1977 do support the Corps’ present inter-
pretation of its mission as extending to so-called “isolated”
waters. Indeed, simple common sense cuts against the par-
ticular definition of the Corps’ jurisdiction favored by the
majority.
I
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. Fed-
eral regulation of the Nation’s waters began in the 19th cen-
tury with efforts targeted exclusively at “promot[ing] water
transportation and commerce.” Kalen, Commerce to Con-
servation: The Call for a National Water Policy and the Evo-
lution 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 1899.3 Section 13 of the 1899 RHA, com-
monly 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.
3 See also Rivers and Harbors Appropriations Act of 1896, 29 Stat. 234;
River and Harbor Act of 1894, 28 Stat. 363; River and Harbor Appropria-
tions Act of 1890, 26 Stat. 426; The River and Harbor Appropriations Act
of 1886, 24 Stat. 329.

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178 SOLID WASTE AGENCY OF NORTHERN COOK CTY.
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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 prevent-
ing 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 dis-
charges 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).4 Seeds of this nascent concern with pollu-
tion control can also be found in the FWPCA, which was
first enacted in 1948 and then incrementally expanded in the
following years.5
4 In 1970, the House Committee on Government Operations followed the
Court’s lead and advocated the use of § 13 as a pollution control provision.
H. R. Rep. No. 91–917, pp. 14–18 (1970). President Nixon responded by
issuing Executive Order No. 11574, 35 Fed. Reg. 19627 (1970) (revoked by
Exec. Order No. 12553, 51 Fed. Reg. 7237 (1986)), which created the Refuse
Act Permit Program. Power, The Fox in the Chicken Coop: The Regula-
tory Program of the U. S. Army Corps of Engineers, 63 Va. L. Rev. 503,
512 (1977) (hereinafter Power). The program ended soon after it started,
however, when a District Court, reading the language of § 13 literally, held
the permit program invalid. Ibid.; see Kalur v. Resor, 335 F. Supp. 1, 9
(DC 1971).
5 The FWPCA of 1948 applied only to “interstate waters.” § 10(e), 62
Stat. 1161. Subsequently, it was harmonized with the Rivers and Harbors
Act such that—like the earlier statute—the FWPCA defined its jurisdic-
tion with reference to “navigable waters.” Pub. L. 89–753, § 211, 80 Stat.
1252. None of these early versions of the FWPCA could fairly be de-
scribed as establishing a comprehensive approach to the problem, but they
did contain within themselves several of the elements that would later be
employed in the CWA. Milwaukee v. Illinois, 451 U. S. 304, 318, n. 10
(1981) (Rehnquist, J.) (Congress intended to do something “quite differ-
ent” in the 1972 Act); 2 W. Rodgers, Environmental Law: Air and Water
§ 4.1, pp. 10–11 (1986) (describing the early versions of the FWPCA).

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Stevens, J., dissenting
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 support-
ers as the first truly comprehensive federal water pollution
legislation. The “major purpose” of the CWA was “to estab-
lish a comprehensive long-range policy for the elimination of
water pollution.” S. Rep. No. 92–414, p. 95 (1971), 2 Legisla-
tive 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’ na-
ture . . . .” 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 Sena-
tor 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 de-
scribed the 1972 amendments as establishing “a comprehen-
sive 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 in-
tended 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 pro-
visions. The earlier statute contains pages of detailed ap-
propriations for improvements in specific navigation facili-
ties, 30 Stat. 1121–1149, for studies concerning the feasibility

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of a canal across the Isthmus of Panama, id., at 1150, and
for surveys of the advisability of harbor improvements at
numerous other locations, id., at 1155–1161. Tellingly, § 13,
which broadly prohibits the discharge of refuse into naviga-
ble waters, contains an exception for refuse “flowing from
streets and sewers . . . in a liquid state.” Id., at 1152.
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 princi-
pal objective of the Act, as stated by Congress in § 101, was
“to restore and maintain the chemical, physical, and bio-
logical 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.
Because of the statute’s ambitious and comprehensive
goals, it was, of course, necessary to expand its jurisdic-
tional scope. Thus, although Congress opted to carry over
the traditional jurisdictional term “navigable waters” from
the RHA and prior versions of the FWPCA, it broadened
the definition of that term to encompass all “waters of the
United States.” § 1362(7).6 Indeed, the 1972 conferees ar-
rived at the final formulation by specifically deleting the
6 The definition of “navigable water” in earlier versions of the FWPCA
had made express reference to navigability. § 211, 80 Stat. 1253.

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word “navigable” from the definition that had originally
appeared in the House version of the Act.7 The majority
today undoes that deletion.
The Conference Report explained that the definition in
§ 502(7) was intended to “be given the broadest possible
constitutional interpretation.” S. Conf. Rep. No. 92–1236,
p. 144 (1972), reprinted in 1 Leg. Hist. 327. The Court dis-
misses this clear assertion of legislative intent with the back
of its hand. Ante, at 168, n. 3. The statement, it claims,
“signifies that Congress intended to exert [nothing] more
than its commerce power over navigation.” Ibid.
The majority’s reading drains all meaning from the con-
ference amendment. By 1972, Congress’ Commerce Clause
power over “navigation” had long since been established.
The Daniel Ball, 10 Wall. 557 (1871); Gilman v. Philadel-
phia, 3 Wall. 713 (1866); Gibbons v. Ogden, 9 Wheat. 1 (1824).
Why should Congress intend that its assertion of federal
jurisdiction be given the “broadest possible constitutional
interpretation” if it did not intend to reach beyond the very
heartland of its commerce power? The activities regulated
by the CWA have nothing to do with Congress’ “commerce
power over navigation.” Indeed, the goals of the 1972 stat-
ute have nothing to do with navigation at all.
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 in-
7 The version adopted by the House of Representatives defined “navi-
gable waters” as “the navigable waters of the United States, including
the territorial seas.” H. R. 11896, 92d Cong., 2d Sess., § 502(8) (1971),
reprinted in 1 Leg. Hist. 1069. The CWA ultimately defined “navigable
waters” simply as “the waters of the United States, including the territo-
rial seas.” 33 U. S. C. § 1362(7).

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182 SOLID WASTE AGENCY OF NORTHERN COOK CTY.
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terest 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 contem-
plated—much less commanded—the odd jurisdictional line
that the Court has drawn today.
The majority accuses respondents of reading the term
“navigable” out of the statute. Ante, at 172. But that was
accomplished by Congress when it deleted the word from the
§ 502(7) definition. After all, it is the definition that is the
appropriate focus of our attention. Babbitt v. Sweet Home
Chapter, Communities for Great Ore., 515 U. S. 687, 697–698,
n. 10 (1995) (refusing to be guided by the common-law defi-
nition of the term “take” when construing that term within
the Endangered Species Act of 1973 and looking instead to
the meaning of the terms contained in the definition of
“take” supplied by the statute). Moreover, a proper under-
standing of the history of federal water pollution regulation
makes clear that—even on respondents’ broad reading—the
presence of the word “navigable” in the statute is not in-
explicable. The term was initially used in the various Riv-
ers and Harbors Acts because (1) at the time those statutes
were first enacted, Congress’ power over the Nation’s waters
was viewed as extending only to “water bodies that were
deemed ‘navigable’ and therefore suitable for moving goods
to or from markets,” Power 513; and (2) those statutes had
the primary purpose of protecting navigation. Congress’
choice to employ the term “navigable waters” in the 1972
Clean Water Act simply continued nearly a century of usage.
Viewed in light of the history of federal water regulation,
the broad § 502(7) definition, and Congress’ unambiguous in-
structions in the Conference Report, it is clear that the term
“navigable waters” operates in the statute as a shorthand
for “waters over which federal authority may properly be
asserted.”

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II
As the majority correctly notes, ante, at 168, 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.8 The reaction to
those regulations in the federal courts,9 in the Environmen-
tal Protection Agency (EPA),10 and in Congress 11 convinced
8 The Corps later acknowledged that the 1974 regulations “limited the
Section 404 permit program to the same waters that were being regulated
under the River and Harbor Act of 1899.” 42 Fed. Reg. 37123 (1977).
Although refusing to defer to the Corps’ present interpretation of the
statute, ante, at 172, the majority strangely attributes some significance
to the Corps’ initial reluctance to read the 1972 Act as expanding its
jurisdiction, ante, at 168 (“Respondents put forward no persuasive evi-
dence that the Corps mistook Congress’ intent in 1974”). But, stranger
still, by construing the statute as extending to nonnavigable tributaries
and adjacent wetlands, the majority reads the statute more broadly than
the 1974 regulations that it seems willing to accept as a correct construc-
tion of the Corps’ jurisdiction. As I make clear in the text, there is abun-
dant evidence that the Corps was wrong in 1974 and that the Court is
wrong today.
9 See, e. g., Natural Resources Defense Council v. Callaway, 392
F. Supp. 685, 686 (DC 1975); United States v. Holland, 373 F. Supp. 665
(MD Fla. 1974).
10 In a 1974 letter to the head of the Corps, the EPA Administrator
expressed his disagreement with the Corps’ parsimonious view of its own
jurisdiction under the CWA. Section 404 of the Federal Water Pollution
Control Act Amendments of 1972: Hearings before the Senate Committee
on Public Works, 94th Cong., 2d Sess., 349 (1976) (letter dated June 19,
1974, from Russell E. Train, Administrator of EPA, to Lt. Gen. W. C. Grib-
ble, Jr., Chief of Corps of Engineers). The EPA is the agency that gen-
erally administers the CWA, except as otherwise provided. 33 U. S. C.
§ 1251(d); see also 43 Op. Atty. Gen. 197 (1979) (“Congress intended to
confer upon the administrator of the [EPA] the final administrative author-
ity” to determine the reach of the term “navigable waters”).
11 The House Committee on Government Operations noted the disagree-
ment between the EPA and the Corps over the meaning of “navigable
waters” and ultimately expressed its agreement with the EPA’s broader
reading of the statute. H. R. Rep. No. 93–1396, pp. 23–27 (1974).

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the Corps that the statute required it “to protect water qual-
ity to the full extent of the [C]ommerce [C]lause” and to ex-
tend 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).
In 1975, the Corps therefore adopted the interim regula-
tions that we upheld in Riverside Bayview. As we noted
in that case, the new regulations understood “the waters
of the United States” to include, not only navigable waters
and their tributaries, but also “nonnavigable intrastate wa-
ters whose use or misuse could affect interstate commerce.”
474 U. S., at 123. The 1975 regulations provided that the
new program would become effective in three phases: phase
1, which became effective immediately, encompassed the nav-
igable waters covered by the 1974 regulation and the RHA;
phase 2, effective after July 1, 1976, extended Corps juris-
diction to nonnavigable tributaries, freshwater wetlands ad-
jacent to primary navigable waters, and lakes; and phase 3,
effective after July 1, 1977, extended Corps jurisdiction to
all other waters covered under the statute, including any
waters not covered by phases 1 and 2 (such as “intermittent
rivers, streams, tributaries, and perched wetlands that are
not contiguous or adjacent to navigable waters”) that “the
District Engineer determines necessitate regulation for the
protection of water quality.” 40 Fed. Reg. 31325–31326
(1975). The final version of these regulations, adopted in
1977, made clear that the covered waters included “isolated
lakes and wetlands, 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.” 12
12 42 Fed. Reg. 37127 (1977), as amended, 33 CFR § 328.3(a)(3) (1977).
The so-called “migratory bird” rule, upon which the Corps based its as-
sertion of jurisdiction in this case, is merely a specific application of the
more general jurisdictional definition first adopted in the 1975 and 1977

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185 Cite as: 531 U. S. 159 (2001)
Stevens, J., dissenting
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 lim-
ited 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. We sum-
marized these debates in our opinion in Riverside Bayview:
“In both Chambers, debate on the proposals to narrow
the definition of navigable waters centered largely on
the issue of wetlands preservation. See [123 Cong.
Rec.], at 10426–10432 (House debate); id., at 26710–26729
(Senate debate). Proponents of a more limited § 404 ju-
risdiction contended that the Corps’ assertion of juris-
diction over wetlands and other nonnavigable ‘waters’
had far exceeded what Congress had intended in enact-
ing § 404. Opponents of the proposed changes argued
that a narrower definition of ‘navigable waters’ for pur-
poses of § 404 would exclude vast stretches of crucial
wetlands from the Corps’ jurisdiction, with detrimental
effects on wetlands ecosystems, water quality, and the
aquatic environment generally. The debate, particu-
larly in the Senate, was lengthy. In the House, the de-
bate ended with the adoption of a narrowed definition of
rules. The “rule,” which operates as a rule of thumb for identifying the
waters that fall within the Corps’ jurisdiction over phase 3 waters, first
appeared in the preamble to a 1986 repromulgation of the Corps’ definition
of “navigable waters.” 51 Fed. Reg. 41217 (1986). As the Corps stated
in the preamble, this repromulgation was not intended to alter its jurisdic-
tion in any way. Ibid. Instead, the Corps indicated, the migratory bird
rule was enacted simply to “clarif[y]” the scope of existing jurisdictional
regulations. Ibid.

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186 SOLID WASTE AGENCY OF NORTHERN COOK CTY.
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Stevens, J., dissenting
‘waters’; but in the Senate the limiting amendment was
defeated and the old definition retained. The Confer-
ence Committee adopted the Senate’s approach: efforts
to narrow the definition of ‘waters’ were abandoned; the
legislation as ultimately passed, in the words of Senator
Baker, ‘retain[ed] the comprehensive jurisdiction over
the Nation’s waters exercised in the 1972 Federal Water
Pollution Control Act.’ ” 474 U. S., at 136–137.
The net result of that extensive debate was a congres-
sional endorsement of the position that the Corps maintains
today. We explained in Riverside Bayview:
“[T]he scope of the Corps’ asserted jurisdiction over
wetlands was specifically brought to Congress’ atten-
tion, and Congress rejected measures designed to curb
the Corps’ jurisdiction in large part because of its con-
cern that protection of wetlands would be unduly ham-
pered by a narrowed definition of ‘navigable waters.’
Although we are chary of attributing significance to
Congress’ failure to act, a refusal by Congress to over-
rule an agency’s construction of legislation is at least
some evidence of the reasonableness of that construc-
tion, particularly where the administrative construction
has been brought to Congress’ attention through legisla-
tion specifically designed to supplant it.” Id., at 137.
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 con-
trary. The majority’s refusal in today’s decision to acknowl-
edge the scope of our prior decision is troubling. Compare

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Stevens, J., dissenting
id., at 136 (“Congress acquiesced in the [1975] administrative
construction [of the Corps’ jurisdiction]”), with ante, at 170
(“We conclude that respondents have failed to make the nec-
essary showing that the failure of the 1977 House bill demon-
strates Congress’ acquiescence to the Corps’ regulations
. . .”). 13 Having already concluded that Congress acquiesced
in the Corps’ regulatory definition of its jurisdiction, the
Court is wrong to reverse course today. See Dickerson v.
United States, 530 U. S. 428, 443 (2000) (Rehnquist, C. J.)
(“ ‘[T]he doctrine [of stare decisis] carries such persuasive
force that we have always required a departure from prece-
dent to be supported by some “special justification” ’ ”).
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,
13 The majority appears to believe that its position is consistent with
Riverside Bayview because of that case’s reservation of the question
whether the Corps’ jurisdiction extends to “certain wetlands not necessar-
ily adjacent to other waters,” 474 U. S., at 124, n. 2. But it is clear from
the context that the question reserved by Riverside Bayview did not con-
cern “isolated” waters, such as those at issue in this case, but rather “iso-
lated” wetlands. See id., at 131–132, n. 8 (“We are not called upon to
address 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 . . .”). Unlike the open waters present on petitioner’s site, wetlands
are lands “that are inundated or saturated by surface or ground water
at a frequency and duration sufficient to support, and that under normal
circumstances do support, a prevalence of vegetation typically adapted
for life in saturated soil conditions. Wetlands generally include swamps,
marshes, bogs, and similar areas.” 33 CFR § 328.3(b) (2000). If, as I be-
lieve, actually navigable waters lie at the very heart of Congress’ com-
merce power and “isolated,” nonnavigable waters lie closer to (but well
within) the margin, “isolated wetlands,” which are themselves only mar-
ginally “waters,” are the most marginal category of “waters of the United
States” potentially covered by the statute. It was the question of the
extension of federal jurisdiction to that category of “waters” that the Riv-
erside Bayview Court reserved. That question is not presented in this
case.

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Stevens, J., dissenting
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.
In addition to the enumerated exceptions, the 1977 amend-
ments included a new section, § 404(g), which authorized the
States to administer their own permit programs over certain
nonnavigable waters. Section 404(g)(1) provides, in rele-
vant part:
“The Governor of any State desiring 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 may submit to
the Administrator a full and complete description of the
program it proposes to establish and administer under
State law or under an interstate compact.” 33 U. S. C.
§ 1344(g)(1).
Section 404(g)(1)’s reference to navigable waters “other
than those waters which are presently used, or are suscepti-
ble to use,” for transporting commerce and their adjacent
wetlands appears to suggest that Congress viewed (and ac-
cepted) the Act’s regulations as covering more than naviga-

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189 Cite as: 531 U. S. 159 (2001)
Stevens, J., dissenting
ble waters in the traditional sense. The majority correctly
points out that § 404(g)(1) is itself ambiguous because it does
not indicate precisely how far Congress considered federal
jurisdiction to extend. Ante, at 171. But the Court ignores
the provision’s legislative history, which makes clear that
Congress understood § 404(g)(1)—and therefore federal ju-
risdiction—to extend, not only to navigable waters and non-
navigable tributaries, but also to “isolated” waters, such as
those at issue in this case.
The Conference Report discussing the 1977 amendments,
for example, states that § 404(g) “establish[es] a process to
allow the Governor of any State to administer an individual
and general permit program for the discharge of dredged or
fill material into phase 2 and 3 waters after the approval of
a program by the Administrator.” H. R. Conf. Rep. No. 95–
830, p. 101 (1977), reprinted in 3 Legislative History of the
Clean Water Act of 1977 (Committee Print compiled for
the Committee on Environment and Public Works by the
Library of Congress), Ser. No. 95–14, p. 285 (emphasis added)
(hereinafter Leg. Hist. of CWA). Similarly, a Senate Re-
port discussing the 1977 amendments explains that, under
§ 404(g), “the [C]orps will continue to administer the section
404 permit program in all navigable waters for a discharge
of dredge or fill material until the approval of a State pro-
gram for phase 2 and 3 waters.” S. Rep. No. 95–370, p. 75
(1977), reprinted in 4 Leg. Hist. of CWA 708 (emphases
added).
Of course, as I have already discussed, “phase 1” wa-
ters are navigable waters and their contiguous wetlands,
“phase 2” waters are the “primary tributaries” of navigable
waters and their adjacent wetlands, and “phase 3” waters
are all other waters covered by the statute, and can include
such “isolated” waters as “intermittent rivers, streams, trib-
utaries, and perched wetlands that are not contiguous or
adjacent to navigable waters.” The legislative history of
the 1977 amendments therefore plainly establishes that,

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190 SOLID WASTE AGENCY OF NORTHERN COOK CTY.
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Stevens, J., dissenting
when it enacted § 404(g), Congress believed—and desired—
the Corps’ jurisdiction to extend beyond just navigable wa-
ters, their tributaries, and the wetlands adjacent to each.
In dismissing the significance of § 404(g)(1), the majority
quotes out of context language in the very same 1977 Senate
Report that I have quoted above. Ante, at 170, n. 6. It is
true that the Report states that “[t]he committee amend-
ment does not redefine navigable waters.” S. Rep. No. 95–
370, at 75, reprinted in 4 Leg. Hist. of CWA 708 (emphasis
added). But the majority fails to point out that the quoted
language appears in the course of an explanation of the
Senate’s refusal to go along with House efforts to narrow
the scope of the Corps’ CWA jurisdiction to traditionally
navigable waters. Thus, the immediately preceding sen-
tence warns that “[t]o limit the jurisdiction of the [FWPCA]
with reference to discharges of the pollutants of dredged
or fill material would cripple efforts to achieve the act’s ob-
jectives.” 14 Ibid. The Court would do well to heed that
warning.
The majority also places great weight, ante, at 171, on our
statement in Riverside Bayview that § 404(g) “does not con-
14 In any event, to attach significance to the Report’s statement that
the committee amendments do not “redefine navigable waters,” one must
first accept the majority’s erroneous interpretation of the 1972 Act. But
the very Report upon which the majority relies states that “[t]he 1972
[FWPCA] exercised comprehensive jurisdiction over the Nation’s waters
to control pollution to the fullest constitutional extent.” S. Rep. No. 95–
370, at 75, reprinted in 4 Leg. Hist. of CWA 708 (emphases added). Even
if the Court’s flawed reading of the earlier statute were correct, however,
the language to which the Court points does not counsel against finding
congressional acquiescence in the Corps’ 1975 regulations. Quite the con-
trary. From the perspective of the 1977 Congress, those regulations con-
stituted the status quo that the proposed amendments sought to alter.
Considering the Report’s favorable references to the Corps’ “continu[ing]”
jurisdiction over phase 2 and 3 waters, the language concerning the failure
of the amendments to “redefine navigable waters” cuts strongly against
the majority’s position, which instead completely excises phase 3 waters
from the scope of the Act. Ibid.

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Stevens, J., dissenting
clusively determine the construction to be placed on the use
of the term ‘waters’ elsewhere in the Act,” 474 U. S., at 138,
n. 11 (emphasis added). This is simply more selective read-
ing. In that case, we also went on to say with respect to
the significance of § 404(g) that “the various provisions of the
Act should be read in pari materia.” Ibid. Moreover, our
ultimate conclusion in Riverside Bayview was that § 404(g)
“suggest[s] strongly that the term ‘waters’ as used in the
Act” supports the Corps’ reading. Ibid.
III
Although it might have appeared problematic on a “lin-
guistic” 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 re-
fuses to extend such deference to the same agency’s con-
struction of the same statute, see ante, at 172–174. 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’ interpreta-
tion of the statute does not “encroac[h]” upon “traditional
state power” over land use. Ante, at 173. “Land use plan-
ning in essence chooses particular uses for the land; environ-
mental 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 regula-
tion is an accepted exercise of federal power. Hodel v. Vir-
ginia Surface Mining & Reclamation Assn., Inc., 452 U. S.
264, 282 (1981).

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192 SOLID WASTE AGENCY OF NORTHERN COOK CTY.
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Stevens, J., dissenting
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 pol-
lution, 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 contin-
ued 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 Illi-
nois 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, tribu-
taries of navigable waters, and wetlands adjacent to each is
manifestly reasonable and therefore entitled to deference.
IV
Because I am convinced that the Court’s miserly construc-
tion of the statute is incorrect, I shall comment briefly on
petitioner’s argument that Congress is without power to pro-
hibit 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 bound-
aries 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) chan-
nels of interstate commerce; (2) instrumentalities of inter-

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state commerce, or persons and things in interstate com-
merce; 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 intra-
state activities that “substantially affect” interstate com-
merce, 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) (noting that it is the “class” of regulated activities,
not the individual instance, that is to be considered in the
“affects” commerce analysis); see also Hodel, 452 U. S., at
277; Wickard v. Filburn, 317 U. S. 111, 127–128 (1942).
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 in-
tended to engage in some other activity besides discharging
fill (i. e., had there been no activity to regulate), or, con-
versely, 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. There can be no doubt that, unlike the class of
activities Congress was attempting to regulate in United
States v. Morrison, 529 U. S. 598, 613 (2000) (“[g]ender-
motivated crimes”), and Lopez, 514 U. S., at 561 (possession
of guns near school property), the discharge of fill material
into the Nation’s waters is almost always undertaken for eco-
nomic reasons. See V. Albrecht & B. Goode, Wetland Regu-
lation in the Real World, Exh. 3 (Feb. 1994) (demonstrating
that the overwhelming majority of acreage for which § 404

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194 SOLID WASTE AGENCY OF NORTHERN COOK CTY.
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Stevens, J., dissenting
permits are sought is intended for commercial, industrial, or
other economic use).15
Moreover, no one disputes that the discharge of fill into
“isolated” waters that serve as migratory bird habitat will,
in the aggregate, adversely affect migratory bird popula-
tions. See, e. g., 1 Secretary of the Interior, Report to Con-
gress, The Impact of Federal Programs on Wetlands: The
Lower Mississippi Alluvial Plain and the Prairie Pothole
Region 79–80 (Oct. 1988) (noting that “isolated,” phase 3
waters “are among the most important and also [the] most
threatened ecosystems in the United States” because “[t]hey
are prime nesting grounds for many species of North Ameri-
can waterfowl . . .” and provide “[u]p to 50 percent of the
[U. S.] production of migratory waterfowl”). Nor does peti-
tioner dispute that the particular waters it seeks to fill are
home to many important species of migratory birds, in-
cluding the second-largest breeding colony of Great Blue
Herons in northeastern Illinois, App. to Pet. for Cert. 3a,
and several species of waterfowl protected by international
treaty and Illinois endangered species laws, Brief for Federal
Respondents 7.16
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
15 The fact that petitioner can conceive of some people who may dis-
charge fill for noneconomic reasons does not weaken the legitimacy of the
Corps’ jurisdictional claims. As we observed in Perez v. United States,
402 U. S. 146 (1971), “[w]here the class of activities is regulated and that
class is within the reach of federal power, the courts have no power to
excise, as trivial, individual instances of the class.” Id., at 154 (internal
quotation marks omitted).
16 Other bird species using petitioner’s site as habitat include the “ ‘Great
Egret, Green-backed Heron, Black-crowned Night Heron, Canada Goose,
Wood Duck, Mallard, Greater Yellowlegs, Belted Kingfisher, Northern
Waterthrush, Louisiana Waterthrush, Swamp Sparrow, and Red-winged
Blackbird.’ ” Brief for Petitioner 4, n. 3.

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literally millions of people regularly participate in bird-
watching and hunting and that those activities generate a
host of commercial activities of great value.17 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. Cf. Gibbs v. Babbitt, 214 F. 3d 483, 492–493
(CA4 2000) (“The relationship between red wolf takings
and interstate commerce is quite direct—with no red wolves,
there will be no red wolf related tourism . . .”).
Finally, the migratory bird rule does not blur the “distinc-
tion between what is truly national and what is truly local.”
Morrison, 529 U. S., at 617–618. Justice Holmes cogently
observed in Missouri v. Holland that the protection of mi-
gratory birds is a textbook example of a national problem.
252 U. S., at 435 (“It is not sufficient to rely upon the States
[to protect migratory birds]. The reliance is vain . . .”).
The destruction of aquatic migratory bird habitat, like so
many other environmental problems, is an action in which
the benefits (e. g., a new landfill) are disproportionately local,
while many of the costs (e. g., fewer migratory birds) are
widely dispersed and often borne by citizens living in other
States. In such situations, described by economists as in-
volving “externalities,” federal regulation is both appro-
priate and necessary. Revesz, Rehabilitating Interstate
17 In 1984, the U. S. Congress Office of Technology Assessment found
that, in 1980, 5.3 million Americans hunted migratory birds, spending
$638 million. U. S. Congress, Office of Technology Assessment, Wetlands:
Their Use and Regulation 54 (OTA–O–206, Mar. 1984). More than 100
million Americans spent almost $14.8 billion in 1980 to watch and photo-
graph fish and wildlife. Ibid. Of 17.7 million birdwatchers, 14.3 million
took trips in order to observe, feed, or photograph waterfowl, and 9.5
million took trips specifically to view other water-associated birds, such as
herons like those residing at petitioner’s site. U. S. Dept. of Interior, U. S.
Fish and Wildlife Service and U. S. Dept. of Commerce, Bureau of Census,
1996 National Survey of Fishing, Hunting, and Wildlife-Associated Recre-
ation 45, 90 (issued Nov. 1997).

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196 SOLID WASTE AGENCY OF NORTHERN COOK CTY.
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Stevens, J., dissenting
Competition: Rethinking the “Race-to-the-Bottom” Ration-
ale for Federal Environmental Regulation, 67 N. Y. U. L.
Rev. 1210, 1222 (1992) (“The presence of interstate externali-
ties is a powerful reason for intervention at the federal
level”); cf. Hodel, 452 U. S., at 281–282 (deferring to Con-
gress’ finding that nationwide standards were “essential” in
order to avoid “destructive interstate competition” that
might undermine environmental standards). Identifying
the Corps’ jurisdiction by reference to waters that serve as
habitat for birds that migrate over state lines also satisfies
this Court’s expressed desire for some “jurisdictional ele-
ment” that limits federal activity to its proper scope. Mor-
rison, 529 U. S., at 612.
The power to regulate commerce among the several States
necessarily and properly includes the power to preserve the
natural resources that generate such commerce. Cf. Spor-
hase v. Nebraska ex rel. Douglas, 458 U. S. 941, 953 (1982)
(holding water to be an “article of commerce”). Migratory
birds, and the waters on which they rely, are such resources.
Moreover, the protection of migratory birds is a well-
established federal responsibility. As Justice Holmes noted
in Missouri v. Holland, the federal interest in protecting
these birds is of “the first magnitude.” 252 U. S., at 435.
Because of their transitory nature, they “can be protected
only by national action.” Ibid.
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 em-
powers 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 ac-
tions that, in the aggregate, would have the same effect.

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Perez, 402 U. S., at 154; Wickard, 317 U. S., at 127–128.18
There is no merit in petitioner’s constitutional argument.
Because I would affirm the judgment of the Court of
Appeals, I respectfully dissent.
18 Justice Thomas is the only Member of the Court who has expressed
disagreement with the “aggregation principle.” United States v. Lopez,
514 U. S. 549, 600 (1995) (concurring opinion).