No. 99-1178 

In the Supreme Court of the United States 

SOLID WASTE AGENCY OF NORTHERN COOK COUNTY, 
PETITIONER 

v. 

UNITED STATES ARMY CORPS OF ENGINEERS, ET AL. 

ON WRIT OF CERTIORARI 
TO THE UNITED STATES COURT OF APPEALS 
FOR THE SEVENTH CIRCUIT 

BRIEF FOR THE FEDERAL RESPONDENTS 

SETH P. WAXMAN 

Solicitor General 

Counsel of Record 

LOIS J. SCHIFFER 

Assistant Attorney General 

LAWRENCE G. WALLACE 

Deputy Solicitor General 

MALCOLM L. STEWART 

Assistant to the Solicitor 

General 

JOSEPH M. FERGUSON 
JOHN A. BRYSON 
JARED A. GOLDSTEIN 

Attorneys 

Department of Justice 
Washington, D.C. 20530-0001 
(202) 514-2217 

QUESTIONS PRESENTED 

Section 404 of the Federal Water Pollution Control Act 
Amendments of 1972, as amended (Clean Water Act), 33 
U.S.C. 1344, authorizes the United States Army Corps of 
Engineers to issue permits for the discharge of dredged or 
fill material into “navigable waters,” defined by the Act as 
“waters of the United States,” see 33 U.S.C. 1362(7). In the 
instant case, the Corps determined that a series of perma- 
nent and seasonal ponds and small lakes on petitioner’s 
property are “waters of the United States” because they are 
used as habitat by numerous species of migratory birds. The 
questions presented are as follows: 

1. Whether the Corps’ determination that the waters at 
issue are subject to its regulatory jurisdiction is based on a 
permissible construction of the Clean Water Act. 

2. Whether use of the waters as migratory bird habitat is 
a constitutionally sufficient basis for the exercise of federal 
regulatory jurisdiction. 

(I) 

TABLE OF CONTENTS 

Page 

Opinions below ............................................................................... 
1 

Jurisdiction ...................................................................................... 1 

Statement ........................................................................................ 1 

Summary of argument .................................................................. 
11 

Argument ........................................................................................ 14 

I. The Corps has reasonably construed the term 

“waters of the United States” to include waters 
whose degradation or destruction could affect 
interstate commerce, even where those waters 

are not navigable in fact and have no surface 
connection to waters that are navigable in 
fact ..................................................................................... 17 

A. The text of the CWA makes clear that the 

Act’s coverage is not limited by traditional 
conceptions of navigability .................................. 
18 

B. The legislative history of the 1972 Act and 
the 1977 amendments supports the Corps’ 
construction of the term “waters of the 

United States” ....................................................... 

21 

C. The Corps’ construction of the statutory 
term “waters of the United States” is 

entitled to deference ............................................. 

28 

II. Use of petitioner’s waters by migratory birds for 
habitat provides a constitutionally sufficient basis 

for federal regulation under the Commerce 
Clause ................................................................................ 36 

A. The protection of migratory bird habitat 

furthers a governmental and public interest 
that has long been recognized to be a matter 
of national concern ................................................ 38 

(III) 

IV 

Table of Contents—Continued: 

Page 

B. The instant case involves commercial 
activity having a substantial impact on 

actual migratory bird habitat .............................. 

43 

C. The destruction of migratory bird habitat 
has substantial effects on interstate 

commerce ................................................................ 47 

Conclusion ....................................................................................... 49 

TABLE OF AUTHORITIES 

Cases: 

Avoyelles Sportsmen’s League, Inc. v. Marsh, 
715 F.2d 897 (5th Cir. 1983) ................................................. 
35 

Babbitt v. Sweet Home Chapter of Communities 
for a Great Or., 515 U.S. 687 (1995) ........................... 
19, 40, 45 

Bob Jones Univ. v. United States, 461 U.S. 574 
(1983) ........................................................................................ 28 

C&A Carbone, Inc. v. Town of Clarkstown, 
511 U.S. 383 (1994) ................................................................ 

43 

CFTC v. Schor, 478 U.S. 833 (1986) ................................... 
29 

Chemical Mfrs. Ass’n v. NRDC, 470 U.S. 116 
(1985) ........................................................................................ 28 

Chevron U.S.A. Inc. v. NRDC, 467 U.S. 837 
(1984) ................................................................................ 

11, 28, 31 

City of Milwaukee v. Illinois, 451 U.S. 304 (1981) .. 
14, 15, 23 

City of N.Y. v. FCC, 486 U.S. 57 (1988) ............................. 
33-34 

City of Philadelphia v. New Jersey, 437 U.S. 617 
(1978) ........................................................................................ 43 

Douglas v. Seacoast Prods., Inc., 431 U.S. 265 
(1977) ........................................................................................ 39 

Exxon Corp. v. Train, 554 F.2d 1310 (5th Cir. 1977) ...... 

35 

FDA v. Brown & Williamson Tobacco Corp., 120 

S. Ct. 1291 (2000) ................................................................... 

28 

Fund for Animals v. Frizzell, 530 F.2d 982 (D.C. 

Cir. 1975) ................................................................................. 40-41 

V 

Cases—Continued: Page 

Gibbs v. Babbitt, 214 F.3d 483 (4th Cir. 2000) .................. 
38 

Hodel v. Indiana 452 U.S. 314 (1981) ................................ 
36 

Hodel v. Virginia Surface Mining & Reclamation 

Ass’n, 452 U.S. 264 (1981) ................................................... 

14, 36 

Hoffman Homes, Inc. v. Administrator, United 

States Envtl. Protection Agency, 999 F.2d 256 (7th 
Cir. 1993) ................................................................................. 

40 
Hughes v. Oklahoma, 441 U.S. 322 (1979) ........................ 
39 

Illinois v. City of Milwaukee, 406 U.S. 91 (1972) ............ 
14 

International Paper Co. v. Ouellette, 479 U.S. 
481 (1987) ................................................................................. 
34 

Jones v. United States, 120 S. Ct. 1904 (2000) ................... 
43 

Katzenbach v. McClung, 379 U.S. 294 (1964) ................... 
36 

Leslie Salt Co. v. United States, 896 F.2d 354 
(9th Cir. 1990), cert. denied, 498 U.S. 1126 (1991) ........... 
35 

McDermott Int’l, Inc. v. Wilander, 498 U.S. 337 
(1991) ........................................................................................ 20 

Middlesex County Sewerage Auth. v. National 

Sea Clammers Ass’n, 453 U.S. 1 (1981) ........................... 
23 

Missouri v. Holland 252 U.S. 416 (1920) ................. 
39, 40, 48 

Natural Resources Defense Council, Inc. v. 

Callaway, 392 F. Supp. 685 (D.D.C. 1975) ....................... 

3-4 

North Dakota v. United States, 460 U.S. 300 
(1983) ......................................................................... 
11, 39, 40, 41 

Oregon Waste Sys., Inc. v. Department of Envtl. 

Quality, 511 U.S. 93 (1994) ................................................. 

43 

Perez v. United States, 402 U.S. 146 (1971) ...................... 
36 

Polish Nat’l Alliance v. NLRB, 322 U.S. 643 
(1944) ........................................................................................ 36 

Quivira Mining Co. v. United States EPA, 765 F.2d 
126 (10th Cir. 1985), cert. denied, 474 U.S. 1055 
(1986) ........................................................................................ 35 

Salinas v. United States, 522 U.S. 52 (1997) .................... 

44 

Taylor v. United States, 495 U.S. 575 (1990) .................... 20 

VI 

Cases—Continued: Page 

United States v. Appalachian Elec. Power Co., 
311 U.S. 377 (1940) ................................................................ 
18 

United States v. Darby, 312 U.S. 100 (1941) ..................... 
32, 36 

United States v. Eidson, 108 F.3d 1336 (11th Cir.), 
cert. denied, 522 U.S. 899 and 1004 (1997) ........................ 
35 

United States v. Hartsell, 127 F.3d 343 (4th Cir. 
1997), cert. denied, 523 U.S. 1030 (1998) ........................... 
35 

United States v. Holland, 373 F. Supp. 665 (M.D. 

Fla. 1974) ................................................................................. 

2, 3 

United States v. Lopez, 514 U.S. 549 (1995) .............. 
10, 15, 36, 

37, 38, 46, 47 

United States v. Morrison, 120 S. Ct. 1740 
(2000) ......................................................................... 
37, 38, 41, 42 
United Staets v. Pozsgai, 999 F.2d 719 (3d Cir. 
1993), cert. denied, 510 U.S. 1110 (1994) ........................... 
35 

United States v. Riverside Bayview Homes, 474 U.S. 
121 (1985) ........................................................................... 
passim 

United States v. Tull, 769 F.2d 182 (4th Cir. 1985), 
rev’d on other grounds, 481 U.S. 412 (1987) ..................... 
35 

Utah v. Marsh, 740 F.2d 799 (10th Cir. 1984) ................... 
42 

Wickard v. Filburn, 317 U.S. 111 (1942) .......................... 
36, 47 

Williamson County Regional Planning Comm’n v. 

Hamilton Bank, 473 U.S. 172 (1985) ................................ 

46 

Constitution, statutes and regulations: 

U.S. Const. Art. I, § 8, Cl. 3 (Commerce Clause) ............ 

passim 

Administrative Procedure Act, 5 U.S.C. 701 et seq. ........... 
9 

Emergency Wetlands Resources Act of 1986, 
16 U.S.C. 3901(a)(2) ............................................................... 
41 

Endangered Species Act of 1973, 16 U.S.C. 1531 
et seq. ........................................................................................ 
18 

16 U.S.C. 1532(19) ............................................................. 
19 

16 U.S.C. 1538(a)(1)(B) ..................................................... 19 

VII 

Statutes and regulations: 

Page 

Federal Water Pollution Control Act Amendments of 
1972, Pub. L. No. 92-500, 86 Stat. 816, as amended, 
Pub. L. No. 95-217, 91 Stat. 1566 (33 U.S.C. 1251 
et seq.) ...................................................................................... 
1 

33 U.S.C. 1251 .................................................................... 
32 

33 U.S.C. 1251(a) ............................................................... 
1 

33 U.S.C. 1251(a)(2) .................................................... 
2, 19, 32 

33 U.S.C. 1251(d) ............................................................... 
3 

33 U.S.C. 1311(a) ......................................................... 
2, 18, 36 

33 U.S.C. 1342 .................................................................... 
36 

33 U.S.C. 1343(c)(1)(A) ..................................................... 
20 

33 U.S.C. 1343(c)(1)(B) ..................................................... 
20 

33 U.S.C. 1343(c)(1)(C) ..................................................... 
20 

33 U.S.C. 1344 ................................................................ 
passim 

33 U.S.C. 1344(b) ............................................................... 
19 

33 U.S.C. 1344(c) ............................................................... 
20 

33 U.S.C. 1344(e) ............................................................... 
45 

33 U.S.C. 1344(f) ................................................................ 
5, 27 

33 U.S.C. 1344(g) ....................................................... 
27, 28, 35 

33 U.S.C. 1344(g)(1) ........................................... 
5, 8, 21, 30, 34 

33 U.S.C. 1344(g)(2) .......................................................... 
21 

33 U.S.C. 1344(g)(3) .......................................................... 
21 

33 U.S.C. 1344(h)(2)(A) .................................................... 
21 

33 U.S.C. 1362(7) ......................................................... 
2, 18, 36 

33 U.S.C. 1362(12) ............................................................. 
36 

33 U.S.C. 1362(12)(A) ....................................................... 
2, 18 

33 U.S.C. 1370 .................................................................... 
35 

Rivers and Harbors Appropriation Act of 1899, § 10, 
33 U.S.C. 403 .......................................................................... 
33 

Water Bank Act, 16 U.S.C. 1301 ............................................ 
41 

Water Pollution Control Act, ch. 758, § 2(d)(1), 62 

Stat. 1156 ................................................................................. 

14 

18 U.S.C. 666(a)(1)(B) ............................................................... 
44 

33 C.F.R.: 

Section 209.120(d)(1) (1974) ................................................. 

2 

Section 209.120(d)(2) (1976) ................................................. 4 

VIII 

Regulations: Page 

Section 209.120(d)(2)(i) (1976) ............................................. 
4, 24 

Section 209.120(e)(2) (1976) ................................................. 
4 

Section 209.260(e)(1) (1974) ................................................. 
2 

Pt. 320 .......................................................................................... 
47 

Section 320.4(j)(2) .................................................................. 
33 

Section 323.2(a)(5) (1978) ...................................................... 
5, 24 

Section 323.2(h)(2) ................................................................. 
34 

Section 328.3(a) ...................................................................... 
17 

Section 328.3(a)(1) .................................................................. 
15 

Section 328.3(a)(2) .................................................................. 
15 

Section 328.3(a)(3) ....................................................... 
5, 16, 29, 32 

Section 330.2(e) ...................................................................... 
16 

40 C.F.R.: 

Section 122.2 ........................................................................... 

4 

Section 230.3(s)(3) .................................................................. 
4, 28 

Section 232.2 ........................................................................... 
4, 28 

Section 233.70 ......................................................................... 
8 

Section 233.71 ......................................................................... 
8 

50 C.F.R. 10.13 .......................................................................... 
6 

Miscellaneous: 

Virginia Carter, Wetland Hydrology, Water Quality, 
and Associated Functions, in United States 
Geological Survey, National Water Summary on 
Wetland Resources (1996) .................................................... 

16 
118 Cong. Rec. (1972): 

p. 33,699 ................................................................................... 

23 

p. 33,756 ................................................................................... 
23 

p. 33,757 ................................................................................... 
24 

123 Cong. Rec. (1977): 

p. 10,415 ................................................................................... 

33 

p. 10,418 ................................................................................... 
25 

p. 10,420 ................................................................................... 
5, 24 

p. 10,421 ................................................................................... 
36 

p. 10,431 ................................................................................... 
25 

p. 10,434 ................................................................................... 5, 24 

IX 

Miscellaneous—Continued: Page 

p. 26,697 ................................................................................... 

33 

p. 26,701 ................................................................................... 
33 

p. 26,710 ................................................................................... 
36 

pp. 26,710-26,711 .................................................................... 
26 

p. 26,711 ................................................................................... 
26 

p. 26,712 ................................................................................... 
35 

p. 26,714 ................................................................................... 
26 

p. 26,716 ................................................................................... 
33 

p. 26,719 ................................................................................... 
33 

p. 26,722 ................................................................................... 
26 

p. 26,728 ................................................................................... 
5, 27 

p. 34,852 ................................................................................... 
25 

p. 39,196 ................................................................................... 
27 

p. 39,209 ................................................................................... 
27 

p. 39,210 ................................................................................... 
27 

Thomas Dahl, U.S. Dep’t of the Interior, Wetlands 

Losses in the United States 1780’s to 1980’s 
(1990) ........................................................................................ 40 

Thomas Dahl & Craig Johnson, U.S. Dep’t of the 

Interior, Status and Trends of Wetlands in the 
Conterminous United States Mid-1970s to Mid- 
1980s (1991) ..................................................................... 
16, 41, 46 

Environmental Policy Div., Library of Congress, 

Legislative History of the Water Pollution Control 
Act Amendments of 1972 (1973) ......................................... 

21-22 
39 Fed. Reg. 12,115 (1974) ....................................................... 
2 

40 Fed. Reg. (1975): 

p. 31,320 ................................................................................... 

4 

p. 31,321 ................................................................................... 
3, 24 

p. 31,324 ................................................................................... 
4 

pp. 31,324-31,325 .................................................................... 
24 

p. 31,325 ................................................................................... 
4 

p. 31,326 ................................................................................... 
4 

p. 31,328 ................................................................................... 
42 

42 Fed. Reg. (1977): 

p. 37,122 ................................................................................... 4 

X 

Miscellaneous—Continued: Page 

p. 37,124 ................................................................................... 

4 

p. 37,144 ................................................................................... 
24 

51 Fed. Reg. (1986): 

p. 41,206 ................................................................................... 

45 

pp. 41,216-41,217 .................................................................... 
6 

p. 41,217 ............................................................................. 
6, 16, 45 

61 Fed. Reg. 65,874 (1996) ....................................................... 
46 

65 Fed. Reg. 12,818 (2000) ....................................................... 
46 

Fish and Wildlife Serv., U.S. Dep’t of the Interior, 

North American Waterfowl Management Plan 
(1986) ................................................................................ 

16, 41, 48 
Fish and Wildlife Serv., U.S. Dep’t of the Interior, 
& Bureau of the Census, U.S. Dep’t of Commerce, 
1996 National Survey of Fishing, Hunting, and 
Wildlife-Associated Recreation (1997) .............................. 
47, 48 

H.R. Conf. Rep. No. 830, 95th Cong., 1st Sess. 
(1977) ........................................................................................ 5 

H.R. Rep. No. 911, 92d Cong., 2d Sess. (1972) ..................... 

22 

H.R. Rep. No. 1396, 93d Cong., 2d Sess. (1974) ................... 
3 

H.R. Rep. No. 139, 95th Cong., 1st Sess. (1977) .................. 
36 

National Research Council, Wetlands: Character- 
istics and Boundaries (1995) ............................................... 
41 

43 Op. Att’y Gen. (1979) ........................................................... 
3 

Oversight Hearings on Section 404 of the Clean Water 

Act: Hearings Before the Subcomm. on Envtl. 
Pollution of the Senate Comm. on Env’t and Pub. 
Works, 99th Cong., 1st Sess. (1985) ................................... 

42 
Section 4o4 of the Federal Water Pollution Control 

Act Amendments of 1972: Hearings Before the 
Senate Comm. on Pub. Works, 94th Cong., 2d 
Sess. (1976) .............................................................................. 

3 
S. Conf. Rep. No. 1236, 92d Cong., 2d Sess. (1972) ............. 
2, 22 

S. Conf. Rep. No. 830, 95th Cong., 1st Sess. (1977) ............ 
27 

S. Rep. No. 414, 92d Cong., 1st Sess. (1971) ......................... 
22 

S. Rep. No. 370, 95th Cong., 1st Sess. (1977) ............... 21, 26, 32 

In the Supreme Court of the United States 

No. 99-1178 

SOLID WASTE AGENCY OF NORTHERN COOK COUNTY, 
PETITIONER 

v. 

UNITED STATES ARMY CORPS OF ENGINEERS, ET AL. 

ON WRIT OF CERTIORARI 
TO THE UNITED STATES COURT OF APPEALS 
FOR THE SEVENTH CIRCUIT 

BRIEF FOR THE FEDERAL RESPONDENTS 

OPINIONS BELOW 

The opinion of the court of appeals (Pet. App. 1a-13a) is 
reported at 191 F.3d 845. The opinion of the district court 
(Pet. App. 14a-36a) is reported at 998 F. Supp. 946. 

JURISDICTION 

The judgment of the court of appeals was entered on 
October 7, 1999. On December 16, 1999, Justice Stevens ex- 
tended the time for filing a petition for a writ of certiorari to 
January 14, 2000, and the petition was filed on that date. 
The jurisdiction of this Court rests on 28 U.S.C. 1254(1). 

STATEMENT 

1. Congress enacted the Federal Water Pollution Control 
Act Amendments of 1972, Pub. L. No. 92-500, 86 Stat. 816, as 
amended, Pub. L. No. 95-217, 91 Stat. 1566, 33 U.S.C. 1251 
et seq. (Clean Water Act or CWA) “to restore and maintain 
the chemical, physical and biological integrity of the Nation’s 
waters.” 33 U.S.C. 1251(a). One of the goals of the CWA is 

(1) 

2 

to attain “water quality which provides for the protection 
and propagation of fish, shellfish, and wildlife.” 33 U.S.C. 
1251(a)(2). A major tool in achieving that purpose is a 
prohibition on the discharge of any pollutants, including 
dredged or fill material, into “navigable waters” except in 
accordance with the Act. 33 U.S.C. 1311(a), 1362(12)(A). 
The CWA provides that “[t]he term ‘navigable waters’ 
means the waters of the United States, including the 
territorial seas.” 33 U.S.C. 1362(7). The Conference Report 
accompanying the CWA explained that “[t]he conferees fully 
intend that the term ‘navigable waters’ be given the 
broadest possible constitutional interpretation unencum- 
bered by agency determinations which have been made or 
may be made for administrative purposes.” S. Conf. Rep. 
No. 1236, 92d Cong., 2d Sess. 144 (1972). 

Discharges of dredged or fill material into “waters of the 
United States” may be authorized by a permit issued by the 
Army Corps of Engineers (Corps) pursuant to Section 404 of 
the CWA, 33 U.S.C. 1344. Regulations implementing the 
Corps’ Section 404 permitting authority were first published 
in 1974. 39 Fed. Reg. 12,115. Those regulations defined the 
term “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 C.F.R. 209.120(d)(1) (1974). See 
also 33 C.F.R. 209.260(e)(1) (1974) (explaining 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”). 

The Corps’ initial view of the scope of its Section 404 
jurisdiction met with substantial opposition. Several federal 
courts considering the coverage of wetlands adjacent to 
other waters held that the Corps had given Section 404 an 
unduly restrictive reading. See, e.g., United States v. 
Holland, 373 F. Supp. 665, 670-676 (M.D. Fla. 1974). The 

3 

court in Holland examined the text and history of the CWA, 
id. at 671-672, as well as this Court’s precedents construing 
the Commerce Clause, and concluded that “Congress had the 
power to go beyond the ‘navigability’ limitation in its control 
over water pollution and that it intended to do so.” Id. at 
673. The Environmental Protection Agency (EPA) and 
the House Committee on Government Operations expressed 
agreement with the decision in Holland.1 In Natural 
Resources Defense Council, Inc. v. Callaway, 392 F. Supp. 
685, 686 (D.D.C. 1975), the court held that in the CWA 
Congress had “asserted federal jurisdiction over the nation’s 
waters to the maximum extent permissible under the 
Commerce Clause of the Constitution. Accordingly, as used 

1 EPA expressed the view that “the Holland decision provides a 
necessary step for the preservation of our limited wetland resources,” and 
that “the [Holland] court properly interpreted the jurisdiction granted 
under the [CWA] and Congressional power to make such a grant.” See 
Section 404 of the Federal Water Pollution Control Act Amendments of 
1972: Hearings Before the Senate Comm. on Pub. Works, 94th Cong., 2d 
Sess. 349 (1976) (letter dated June 19, 1974, from Russell E. Train, 
Administrator of EPA, to Lt. Gen. W.C. Gribble, Jr., Chief of Corps of 
Engineers). EPA explained that it “firmly believe[d] that the Conference 
Committee deleted ‘navigable’ from the [CWA] definition of ‘navigable 
waters’ in order to free pollution control from jurisdictional restrictions 
based on ‘navigability.’ ” Id. at 350. Shortly thereafter, the House Com- 
mittee on Government Operations discussed the disagreement between 
the two agencies (as reflected in EPA’s June 19 letter) and concluded that 
the Corps should adopt the broader view of the term “waters of the 
United States” taken by EPA and by the court in Holland. See H.R. Rep. 
No. 1396, 93d Cong., 2d Sess. 23-27 (1974). The Committee urged the 
Corps to adopt a new definition that “complies with the congressional 
mandate that this term be given the broadest possible constitutional 
interpretation.” Id. at 27 (internal quotation marks omitted). 

EPA administers the CWA except as otherwise explicitly provided. 33 
U.S.C. 1251(d). The Attorney General has determined that the “ultimate 
administrative authority to determine the reach of the term ‘navigable 
waters’ for purposes of § 404” resides with EPA. 43 Op. Att’y Gen. 197 
(1979). 

4 

in the Water Act, the term [‘navigable waters’] is not limited 
to the traditional tests of navigability.” The court ordered 
the Corps to publish new regulations “clearly recognizing 
the full regulatory mandate of the Water Act.” Ibid. 

In response to the district court’s order in Callaway, the 
Corps promulgated interim final regulations providing for a 
phased-in expansion of its Section 404 jurisdiction. 40 Fed. 
Reg. 31,320 (1975); see 33 C.F.R. 209.120(d)(2) and (e)(2) 
(1976). The interim regulations revised the definition of 
“waters of the United States” to include, inter alia, waters 
(sometimes referred to as “isolated waters”) that are not 
connected by surface water or adjacent to traditional navig- 
able waters. 33 C.F.R. 209.120(d)(2)(i) (1976).2 On July 19, 
1977, the Corps published its final regulations, in which it 
revised the 1975 interim regulations to clarify many of the 
definitional terms. 42 Fed. Reg. 37,122. The 1977 final 
regulations defined the term “waters of the United States” 
to include, inter alia, “isolated wetlands and lakes, inter- 
mittent 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.” 33 
C.F.R. 323.2(a)(5) (1978).3 The Corps’ current regulation 

2 Phase I, which was immediately effective, included coastal waters 
and traditional inland navigable waters and their adjacent wetlands. 40 
Fed. Reg. 31,321, 31,324, 31,326 (1975). Phase II, which took effect on July 
1, 1976, extended the Corps’ jurisdiction to lakes and primary tributaries 
of Phase I waters, as well as wetlands adjacent to the lakes and primary 
tributaries. Ibid. Phase III, which took effect on July 1, 1977, extended 
the Corps’ jurisdiction to all remaining areas encompassed by the regu- 
lations, including “intermittent rivers, streams, tributaries, and perched 
wetlands that are not contiguous or adjacent to navigable waters.” Id. at 
31,325; see also 42 Fed. Reg. 37,124 (1977) (describing the three phases). 

3 An explanatory footnote published in the Code of Federal Regula- 
tions stated that “[p]aragraph (a)(5) incorporates all other waters of the 
United States that could be regulated under the Federal government’s 

5 

contains similar language, see 33 C.F.R. 328.3(a)(3),4 and 
EPA has promulgated regulations that include a sub- 
stantially identical definition of the term “waters of the 
United States.” See 40 C.F.R. 230.3(s)(3); 40 C.F.R. 232.2; 40 
C.F.R. 122.2. 

In 1977, Congress considered a legislative proposal that 
would have limited the class of waters subject to the Corps’ 
permitting authority under Section 404 of the CWA. A bill 
passed by the House of Representatives provided that for 
purposes of Section 404, the Corps’ permitting authority 
would extend to navigable waters “and adjacent wetlands,” 
with the term “navigable waters” defined to mean waters 
navigable in fact, or capable of being made so by “reasonable 
improvement.” 123 Cong. Rec. 10,420 (1977); see id. at 
10,434 (passage of bill). A similar amendment was defeated 
in the Senate, however, see id. at 26,728, and the provision to 
redefine the term “navigable waters” was eliminated by the 
Conference Committee, see H.R. Conf. Rep. No. 830, 95th 
Cong., 1st Sess. 97-105 (1977).5 

Constitutional powers to regulate and protect interstate commerce.” 33 
C.F.R. 323.2(a)(5), at 616 n.2 (1978). 

4 The current regulation defines “waters of the United States” to 
include, inter alia, “[a]ll other 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 C.F.R. 328.3(a)(3). 

5 Although Congress declined to diminish the geographic scope of the 
Corps’ regulatory jurisdiction, it amended Section 404 in significant re- 
spects. Inter alia, the 1977 Act, Pub. L. No. 95-217, 91 Stat. 1566, estab- 
lished a mechanism by which a State may assume responsibility for 
administration of the Section 404 program with respect to waters “other 
than” traditional navigable waters and their adjacent wetlands. 33 U.S.C. 
1344(g)(1). The 1977 legislation also exempted specified activities—most 
notably certain agricultural and silvicultural activities—from Section 404’s 
permit requirements. See 33 U.S.C. 1344(f). 

6 

In 1986, the Corps consolidated and recodified its regula- 
tory provisions defining “waters of the United States” for 
purposes of the Section 404 program. See 51 Fed. Reg. 
41,216-41,217 (1986). The Corps explained that the new 
regulations neither reduced nor expanded its jurisdiction. 
Id. at 41,217. Rather, their “purpose was to clarify the scope 
of the 404 program by defining the terms in accordance with 
the way the program is presently being conducted.” Ibid. In 
the preamble to the regulations, the Corps observed that 
EPA had “clarified that waters of the United States” include 
waters “[w]hich are or would be used as habitat by birds 
protected by Migratory Bird Treaties,” as well as waters 
“[w]hich are or would be used as habitat by other migratory 
birds which cross state lines.” Ibid. 

2. a. Petitioner is a consortium of Illinois municipalities 
formed for the purpose of locating and developing a disposal 
site for nonhazardous waste. Pet. App. 1a-2a. Petitioner 
owns a 533-acre parcel of land in Cook and Kane Counties, 
Illinois, on which it proposed to locate a solid waste landfill. 
Ibid. The project site is 410 acres in size, 298 acres of which 
is an “early successional stage forest.” Id. at 2a. Although 
the site was used 50 years ago for surface mining, it has 
evolved to include “over 200 permanent and seasonal ponds 

* * * rang[ing] from less than one-tenth of an acre to 
several acres in size, and from several inches to several feet 
in depth.” Ibid. The site functions as a single aquatic 
ecosystem, i.e., “a large wooded wetland complex.” Pet. C.A. 
App. 72 (Administrative Record (A.R.) 16,793); see also Fed. 
C.A. App. 31 (A.R. 15,691) (“[T]he aquatic areas are part of a 
large, contiguous forested ecosystem.”); Fed. C.A. App. 296 
(A.R. 44,708). The site is also located directly above an 
aquifer that supplies drinking water to the region. Fed. C.A. 
App. 89, 94-102 (A.R. 15,748, 15,753-15,761); Pet. C.A. App. 
93 (A.R. 15,581). 

The ponds on petitioner’s land are inhabited by a wide 
variety of aquatic wildlife, including such fish as largemouth 

7 

bass, carp, bluegill, and black crappie; five species of toads 
and frogs; two turtle species; and several salamander 
species. A.R. 40,302, 40,364. In addition, 121 different 
species of birds have been observed on the project site, in- 
cluding species that “depend on aquatic environments for a 
significant portion of their life requirements” and “migrate 
through portions of the United States.” Pet. C.A. App. 90 
(A.R. 15,578); see also Fed. C.A. App. 6-10 (A.R. 2464-2468) 
(“Master List of Bird Species Known to Use the Balefill 
Site”). “Among the species that have been seen nest- 
ing, feeding, or breeding at the site are mallard ducks, 
wood ducks, Canada geese, sandpipers, kingfishers, water 
thrushes, swamp [sparrows], redwinged blackbirds, tree 
swallows, and several varieties of herons.” Pet. App. 3a. 
Each of the above-listed species is on the list of migratory 
bird species protected under international treaties. See 50 
C.F.R. 10.13. “[T]he site is a seasonal home to the second- 
largest breeding colony of great blue herons in northeastern 
Illinois, with approximately 192 nests in 1993.” Pet. App. 3a. 
In addition, the ponds provide breeding habitat for several 
bird species that have been listed as threatened or endan- 
gered by the Illinois Endangered Species Protection Board, 
including the Veery and the Cooper’s Hawk, which require 
isolated aquatic habitats for breeding. Pet. C.A. App. 99-100 
(A.R. 15,587-15,588); Fed. C.A. App. 191, 288 (A.R. 16,383, 
40,418). More than 50 species of birds are known to breed on 
the site. Ibid.; see also Fed. C.A. App. 285 (A.R. 40,415).6 

b. Petitioner’s proposed landfill would involve the filling 
of approximately 17.6 acres of the ponds and small lakes on 
its property. Pet. App. 3a, 15a. The Corps initially con- 
cluded that the site did not contain any “waters of the 
United States” subject to its regulatory jurisdiction. See 
Pet. C.A. App. 60-61. After receiving evidence from the 

6 The site also provides habitat for 30 mammal species and 200 plant 
species. Pet. C.A. App. 92-93 (A.R. 15,580-15,581). 

8 

Illinois Nature Preserves Commission, however, the Corps 
found that the water bodies on petitioner’s property are 
“waters of the United States” because, inter alia, “the water 
areas are used as habitat by migratory bird[s] which cross 
state lines.” Id. at 90 (A.R. 15,578); see also Pet. App. 3a-4a, 
15a-16a. Petitioner subsequently applied to the Corps for a 
Section 404 permit to fill those waters.7 See Pet. C.A. App. 
85-86 (A.R. 15,573-15,574); Pet. App. 3a-4a, 16a. 

In July 1994, after an extensive public review process and 
input from numerous local, state, and federal agencies, the 
Corps denied petitioner’s permit application. Pet. C.A. App. 
84-171 (A.R. 16,672, 15,573-15,659); Pet. App. 4a, 16a. The 
Corps based the permit denial on its findings that (1) the 
filling of the ponds and other waters on the site would elimi- 
nate habitat for numerous species of birds and other wildlife, 
Pet. C.A. App. 155-157 (A.R. 15,643-15,645); Fed. C.A. App. 
32-40 (A.R. 15,692-15,700); (2) petitioner had failed to 
examine available alternatives to the proposed landfill that 
would be less environmentally damaging, Pet. C.A. App. 170 
(A.R. 15,658); and (3) the project poses “an unacceptable risk 
to the public’s drinking water supply” due to the possibility 
that leachate from the landfill could contaminate ground- 
water aquifers, Pet. C.A. App. 171 (A.R. 15,659). 

The Corps found that the site is especially important as 
wildlife habitat due to the loss of similar wooded aquatic 
habitats in the region. Pet. C.A. App. 155 (A.R. 15,643); Fed. 
C.A. App. 33 (A.R. 15,693). It noted the views of some 

7 As noted above (see note 5, supra), the CWA in its current form 
provides a mechanism by which a State may assume responsibility for 
administration of the Section 404 program with respect to waters “other 
than” traditional navigable waters and their adjacent wetlands. 33 U.S.C. 
1344(g)(1). Two States—Michigan and New Jersey—have submitted and 
obtained approval of their own programs for partial administration of the 
Section 404 program. See 40 C.F.R. 233.70, 233.71. Because Illinois has 
not assumed that function, administration of Section 404 with respect to 
the waters at issue in this case remains the responsibility of the Corps. 

9 

experts that “[m]uch of the current severe drop in area- 
sensitive bird populations is blamed on habitat destruction.” 
Ibid. The Corps’ assessment was based in part on the re- 
commendation of the United States Fish and Wildlife 
Service (FWS), which conducted an extensive analysis, see 
Fed. C.A. App. 190-198 (A.R. 16,382-16,390), and concluded 
that “[b]ecause of its value to migratory birds, we do not be- 
lieve this site is an appropriate place to site a landfill.” Id. at 
197 (A.R. 16,389); see Pet. C.A. App. 93 (A.R. 15,581) (Corps’ 
decision document notes the FWS’s recommendation).8 

3. Petitioner sought review of the Corps’ decision in 
federal district court under the Administrative Procedure 
Act, 5 U.S.C. 701 et seq. Pet. App. 14a. Petitioner chal- 
lenged both the Corps’ assertion of regulatory jurisdiction 
and the merits of the permit denial. Id. at 1a. The district 
court granted summary judgment for the government on the 
issue of CWA jurisdiction. Id. at 14a-36a. Petitioner then 
consented to dismissal with prejudice of its remaining claims, 
and the district court entered final judgment in favor of the 
government. Id. at 2a. 

4. The court of appeals affirmed. Pet. App. 1a-13a. The 
court observed that petitioner had “abandoned its challenge 
to the merits of the Corps’ decisions and ha[d] instead 
focused exclusively on its challenge to” the Corps’ assertion 

8 FWS explained that “the project has a high probability of adversely 
affecting breeding habitat of area-sensitive migratory birds, and will likely 
result in the abandonment of the site by breeding great blue herons.” 
Fed. C.A. App. 190 (A.R. 16,382). It observed that “[h]abitat area require- 
ments for forest birds in the midwest are scarce or lacking,” id. at 192 
(A.R. 16,384), and that preservation of existing sites is accordingly 
important. The FWS acknowledged “the enormity of the solid waste dis- 
posal problem and * * * [the Corps’] mandate to balance competing 
interests” but stated that “the continued incremental loss of significant 
habitat for species of concern and its implication for the long-term 
preservation of biological diversity is a societal problem on par with solid 
waste disposal.” Id. at 197 (A.R. 16,389). 

10 

of regulatory jurisdiction. Id. at 4a. The court therefore 
“accept[ed] as true the Corps’ factual findings with regard to 
[petitioner’s] permit application, including the crucial finding 
that the waters of this site were a habitat for migratory 
birds.” Id. at 5a. 

a. The court of appeals rejected petitioner’s contention 
that “Congress lacked the power to grant the Corps regula- 
tory jurisdiction over isolated, intrastate waters based on 
the presence of migratory birds alone.” Pet. App. 5a. Prior 
to this Court’s decision in United States v. Lopez, 514 U.S. 
549 (1995), the court explained, “it had been established that 
Congress’ powers under the Commerce Clause were broad 
enough to permit regulation of waters based on the presence 
of migratory birds.” Pet. App. 5a (citing cases). The court 
found that Lopez had not undermined that rule. It observed 
that “Lopez expressly recognized, and in no way disap- 
proved, 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.” Id. at 6a. 

The court summarized statistical evidence showing that 
Americans engage in frequent interstate travel and spend 
substantial sums of money in order to hunt and observe 
migratory birds. Pet. App. 7a. It concluded that 

the destruction of migratory bird habitat and the atten- 
dant decrease in the populations of these birds “sub- 
stantially affects” interstate commerce. The effect may 
not be observable as each isolated pond used by the birds 
for feeding, nesting, and breeding is filled, but the 
aggregate effect is clear, and that is all the Commerce 
Clause requires. 

Ibid. The court also stated that “the numerous international 
treaties and conventions designed to protect migratory 
birds, * * * as well as the case law recognizing the ‘national 

11 

interest of very nearly the first magnitude’ in protecting 
such birds,” refuted petitioner’s contention that the 
protection of migratory bird habitat is a matter of purely 
local concern. Id. at 8a (quoting North Dakota v. United 
States, 460 U.S. 300, 309 (1983)). 

b. The court of appeals rejected petitioner’s argument 
that the Corps’ exercise of regulatory jurisdiction exceeded 
its authority under the CWA. The court observed that the 
construction of the statutory term “waters of the United 
States” utilized by the Corps and EPA is entitled to 
deference under Chevron U.S.A. Inc. v. Natural Resources 
Defense Council, Inc., 467 U.S. 837 (1984). Pet. App. 9a. 
The court found it “well established that the geographical 
scope of the Act reaches as many waters as the Commerce 
Clause allows.” Ibid. (citing cases). It concluded that, 
“[b]ecause Congress’ power under the Commerce Clause is 
broad enough to permit regulation of waters based on the 
presence of migratory birds, it is certainly reasonable for the 
EPA and the Corps to interpret the Act in such a manner.” 
Id. at 10a. The court of appeals also observed that in the 
present case, “the unchallenged facts show that the filling of 
the 17.6 acres would have an immediate effect on migratory 
birds that actually use the area as a habitat. Thus, we need 
not, and do not, reach the question of the Corps’ jurisdiction 
over areas that are only potential habitats.” Ibid. 

SUMMARY OF ARGUMENT 

A. The Corps and EPA have reasonably asserted CWA 
regulatory jurisdiction over all surface water bodies the 
degradation of which can be expected to affect interstate 
commerce. 

1. By using the term “waters of the United States,” 
Congress signaled its intent that the CWA’s coverage is not 
limited by traditional conceptions of navigability. That con- 
clusion is reinforced by other textual provisions, which 
declare the Act’s purposes to include protection of fish and 

12 

wildlife and require the Corps to consider a broad range of 
interests in evaluating permit applications. And, signifi- 
cantly, Congress amended the CWA in 1977 to authorize 
States to administer the Section 404 program for waters 
“other than” traditional navigable waters and their adjacent 
wetlands. That provision would be meaningless if the Corps’ 
jurisdiction were limited to traditional navigable waters. 

2. The legislative history of the 1972 Act suggests that 
the CWA’s coverage does not depend upon the suitability of 
particular waters for commercial traffic. By 1977, moreover, 
the Corps had asserted regulatory jurisdiction over 
“isolated” waters whose destruction could affect interstate 
commerce. During the debates on the 1977 amendments, 
the propriety of the Corps’ assertion of jurisdiction over 
“isolated” waters was a principal subject of congressional 
concern. Legislative proposals that would have restricted 
the Corps’ jurisdiction to traditional navigable waters and 
their adjacent wetlands were passed by the House and 
introduced in the Senate, but Congress ultimately declined 
to enact any such measure. Congress chose instead to 
counterbalance Section 404’s extensive geographic reach by 
authorizing partial administration of the Section 404 
program by the States, and by exempting specified activities 
from Section 404’s permit requirements. Congress’s refusal 
to overrule the Corps’ construction of the CWA, together 
with its enactment of a new statutory provision that 
presumed the correctness of the existing regulatory 
definition, shows the reasonableness of the Corps’ approach. 

3. The Corps’ interpretation of the phrase “waters of the 
United States” is entitled to deference, since the phrase is 
neither an established term of art nor one with an obvious 
“plain meaning.” The Corps and EPA reasonably chose to 
employ a jurisdictional standard that turns on the prospect 
of interstate effects resulting from water pollution, rather 
than on a particular causal mechanism (surface water 
connections to traditional navigable waters) by which those 

13 

effects are produced. That approach is consistent with the 
text and history of the statute, with established admini- 
strative law precedents, and with principles of federalism. 

B. The Corps’ assertion of regulatory jurisdiction over 
“isolated” waters used as habitat by migratory birds is 
constitutional. 

1. This Court has emphasized that limits on Commerce 
Clause authority serve ultimately to ensure that Congress 
does not assume a general police power or usurp functions 
more appropriately exercised by the States. The Court has 
long recognized, however, that the protection of migratory 
birds is primarily entrusted to the federal government be- 
cause it is a task inherently unsuited to piecemeal accom- 
plishment. The protection of suitable habitat is an integral 
feature of federal efforts to conserve migratory birds. Re- 
affirmation of federal power to protect migratory bird 
habitat is fully in keeping with traditional conceptions of the 
distinction between national and local spheres of authority. 

2. The proposed activity for which petitioner sought a 
permit is commercial in character, and it would have a 
substantial impact on the bird species that use the area for 
habitat. The Court’s inquiry should focus on the facts of this 
case, rather than on hypothetical applications of the Corps’ 
jurisdictional rule to non-economic conduct. That approach 
is especially appropriate because the loss of migratory bird 
habitat has been caused overwhelmingly by commercial 
activities. Moreover, the Corps’ rule is in terms self-limiting 
to applications within the commerce power. 

3. The destruction of migratory bird habitat can be ex- 
pected to have a substantial aggregate effect on interstate 
commerce. Bird hunting and bird watching activities each 
generate billions of dollars of commerce each year. Pro- 
tection of national economic resources from the ill effects of 
local commercial activity is well within Congress’s authority 
under the Commerce Clause. 

14 

ARGUMENT 

This Court has recognized that “the power conferred by 
the Commerce Clause [is] broad enough to permit con- 
gressional regulation of activities causing air or water 
pollution, or other environmental hazards that may have 
effects in more than one State.” Hodel v. Virginia Surface 
Mining & Reclamation Ass’n, 452 U.S. 264, 282 (1981). The 
CWA reflects Congress’s recognition that the degradation of 
water resources in one State may have significant interstate 
effects. See, e.g., City of Milwaukee v. Illinois, 451 U.S. 304, 
325-326 (1981) (explaining that the CWA provides a variety 
of mechanisms by which a State whose waters may be 
affected by a pollutant discharge in another State can parti- 
cipate in the permitting process). In defining the statutory 
term “waters of the United States,” the Corps and EPA 
have identified categories of waters the degradation of which 
can be expected to cause significant harms in States other 
than that in which the pollution occurs. 

The potential for interstate harm, and the consequent 
need for federal regulation, is particularly clear with respect 
to water bodies that span more than one State. It could not 
plausibly be contended, for example, that Illinois authorities 
should have the final say regarding the circumstances under 
which pollutants may be placed into the Mississippi River in 
Illinois. Indeed, long before the enactment of the CWA, the 
Water Pollution Control Act, ch. 758, § 2(d)(1), provided a 
federal mechanism for abatement of “[t]he pollution of 
interstate waters in or adjacent to any State or States 

* * * which endangers the health or welfare of persons in a 
State other than that in which the discharge originates.” 62 
Stat. 1156; see also Illinois v. City of Milwaukee, 406 U.S. 
91, 102-108 (1972) (holding, prior to enactment of the CWA, 
that Illinois could assert a federal common-law cause of 
action to abate the pollution of Lake Michigan by a 

15 

municipality in another State).9 Consistent with that 
longstanding federal policy, the Corps defines the term 
“waters of the United States” to include “[a]ll interstate 
waters including interstate wetlands.” 33 C.F.R. 328.3(a)(2). 

As petitioner recognizes (Br. 15-16), Congress also has 
well-established authority to regulate and protect water 
bodies that are located entirely within a single State but that 
provide actual or potential channels for interstate com- 
mercial traffic. The authority to protect such waterways is 
simply one aspect of Congress’s power to “regulate the use 
of the channels of interstate commerce.” United States v. 
Lopez, 514 U.S. 549, 558 (1995). The Corps’ regulation de- 
fines the term “waters of the United States” to include “[a]ll 
waters which are currently used, or were used in the past, or 
may be susceptible to use in interstate or foreign commerce, 
including all waters which are subject to the ebb and flow of 
the tide.” 33 C.F.R. 328.3(a)(1). 

The Corps’ regulation further recognizes that water 
pollution can affect national interests even where the waters 
in question are located entirely within a single State and are 
unsuitable for use as avenues for commerce. Thus, the 
Corps defines the term “waters of the United States” to 
include (in addition to the categories described above) “[a]ll 
other waters * * * the use, degradation or destruction of 
which could affect interstate or foreign commerce.” 33 
C.F.R. 328.3(a)(3). The Corps has not purported to offer a 
comprehensive list of the circumstances under which 
degradation of so-called “isolated” waters can be expected to 

9 The Court has since held that the CWA preempts a federal common- 
law cause of action for interstate harms caused by water pollution, on the 
ground that Congress “has occupied the field through the establishment of 
a comprehensive regulatory program supervised by an expert admini- 
strative agency.” City of Milwaukee v. Illinois, 451 U.S. at 317. 

16 

have the requisite effect on interstate or foreign commerce. 

10 

It has, however, expressed the view that intrastate waters 
“[w]hich are or would be used as habitat by birds protected 
by Migratory Bird Treaties,” or “[w]hich are or would be 
used as habitat by other migratory birds which cross state 
lines,” fall within the coverage of Section 328.3(a)(3). See 51 
Fed. Reg. 41,217 (1986). 

Taken as a whole, the Corps’ regulation reflects an effort 
to identify categories of waters the degradation of which can 
be expected to have significant interstate effects, making 
protection of the relevant waters an appropriate subject of 
federal concern. The effect of identifying particular waters 
as “waters of the United States,” it should be emphasized, is 
not to impose an absolute prohibition on the discharge of 
pollutants (including dredged and fill material). It is instead 
to ensure that such discharges will not be made without a 
federal permit. The Corps reasonably adopted a broad 
definition of the term “waters of the United States” in order 
to ensure that waters having potential interstate significance 
are not destroyed or degraded without a prior assessment of 

10 The term “isolated waters” is potentially misleading. The term is 
commonly used to refer to waters that are remote from and lack any sur- 
face connection to navigable waters as traditionally defined. See 33 C.F.R. 
330.2(e). Even so-called “isolated waters,” however, may have other 
hydrologic connections to, and affect the quality of, traditional navigable 
waters. “Isolated” waters may, for example, have groundwater connec- 
tions to other waters. Many “isolated” waters also play an important role 
in flood control and erosion control, reducing the size and duration of 
floods by providing storage basins in flood prone areas. See generally 
Virginia Carter, Wetland Hydrology, Water Quality, and Associated 
Functions, in United States Geological Survey, National Water Sum- 
mary on Wetland Resources 44 (1996); Thomas Dahl & Craig Johnson, 
U.S. Dep’t of the Interior, Status and Trends of Wetlands in the 
Conterminous United States, Mid-1970’s to Mid-1980’s at 3 (1991); Fish 
and Wildlife Serv., U.S. Dep’t of the Interior, North American Waterfowl 
Management Plan 11 (1986) (Waterfowl Plan). 

17 

their ecological importance and the likely impacts of the 
proposed activity. 

Petitioner asserts two distinct challenges to the Corps’ 
application of Section 328.3(a) to the development proposal 
at issue. First, petitioner contends that as a matter of 
statutory interpretation, the Corps’ regulatory authority 
under the CWA is limited to waters that are either (1) usable 
for navigation in their current state or through reasonable 
improvement, or (2) connected through surface waters to 
waters that are navigable under the traditional conception of 
that term. Second, petitioner argues that as a matter of 
constitutional law, the use of waters as habitat by migratory 
birds provides a constitutionally insufficient basis for federal 
protection of those waters pursuant to the Commerce 
Clause. For the reasons that follow, those arguments lack 
merit. 

I. THE CORPS HAS REASONABLY CONSTRUED 

THE TERM “WATERS OF THE UNITED 
STATES” TO INCLUDE WATERS WHOSE DE- 
GRADATION OR DESTRUCTION COULD 

AFFECT INTERSTATE COMMERCE, EVEN 
WHERE THOSE WATERS ARE NOT NAVIG- 
ABLE IN FACT AND HAVE NO SURFACE CON- 
NECTION TO WATERS THAT ARE NAVIGABLE 
IN FACT 

The CWA was enacted in 1972 and substantially amended 
in 1977. As we explain below, the text and history of the 
1972 Act reflected a congressional intent to expand the Act’s 
coverage beyond the scope of prior water pollution laws—an 
expansion that suggested, but perhaps did not compel, the 
conclusion that the term “waters of the United States” en- 
compasses isolated waters whose degradation or destruction 
could affect interstate commerce. See pp. 2-3 and note 1, 
supra (describing early discrepancy in approach between the 

18 

Corps and EPA). By 1977, however, the Corps had pro- 
mulgated regulations that comprehensively construed the 
CWA to cover isolated waters, and Congress in 1977 en- 
gaged in prolonged debate regarding the propriety of that 
construction. In the end, Congress acquiesced in the Corps’ 
(and EPA’s) construction of the disputed statutory language, 
both by rejecting legislative proposals that would have 
narrowed the Corps’ jurisdiction, and by amending the Act 
in a manner that presupposed the correctness of the Corps’ 
approach. 

A. The Text Of The CWA Makes Clear That The Act’s 

Coverage Is Not Limited By Traditional Conceptions 

Of Navigability 

1. The CWA proscribes the discharge of any “pollutant” 
into “navigable waters” except in accordance with the Act. 
See 33 U.S.C. 1311(a), 1362(12)(A). Standing alone, Con- 
gress’s use of the phrase “navigable waters”—an existing 
term of art with an established legal meaning—might have 
suggested an intent to confine the Act’s coverage to waters 
suitable for commercial traffic either in their natural state or 
with reasonable improvements. See, e.g., United States v. 
Appalachian Elec. Power Co., 311 U.S. 377, 406-408, 416-417 
(1940). Other provisions of the original CWA, however, 
indicated that the coverage of the Act was not so limited. 
Most obviously, the term “navigable waters” was defined 
to include “the waters of the United States,” 33 U.S.C. 
1362(7)—a term of evident breadth, and one with no pre- 
viously established legal meaning. 

11 As the Court observed 
in United States v. Riverside Bayview Homes, 474 U.S. 121, 

11 Although petitioner suggests (see Br. 16, 18) that the term “waters 
of the United States” has an established legal meaning, the cases on which 
it relies all employed the term “navigable waters of the United States.” 
Petitioner identifies no authority suggesting that the term “waters of the 
United States,” standing alone, has traditionally implied any requirement 
of suitability for use by commercial traffic. 

19 

133 (1985), “the Act’s definition of ‘navigable waters’ as ‘the 
waters of the United States’ makes it clear that the term 
‘navigable’ as used in the Act is of limited import.” Cf. 
Babbitt v. Sweet Home Chapter of Communities for a Great 
Or., 515 U.S. 687, 705 (1995) (“An obviously broad word that 
the Senate went out of its way to add to an important 
statutory definition is precisely the sort of provision that 
deserves a respectful reading.”). 

12 

Other features of the CWA in its original form reinforced 
the conclusion that the Act was not limited to water bodies 
meeting traditional tests of navigability. Inter alia, the Act 
expresses Congress’s objective of attaining “water quality 
which provides for the protection and propagation of fish, 
shellfish, and wildlife.” 33 U.S.C. 1251(a)(2). The Act also 
directs the Corps in evaluating permit applications to con- 
sider guidelines developed by EPA in conjunction with the 
Corps, see 33 U.S.C. 1344(b); and EPA in formulating those 

12 In Sweet Home, the Court considered Section 9(a)(1)(B) of the 
Endangered Species Act (ESA) of 1973, 16 U.S.C. 1531 et seq., which 
makes it unlawful to “take” any endangered or threatened species. 515 
U.S. at 691 (quoting 16 U.S.C. 1538(a)(1)(B)). The ESA defines “take” to 
mean “to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or 
collect, or to attempt to engage in any such conduct.” Ibid. (quoting 16 
U.S.C. 1532(19)). The Court rejected the contention that construction of 
the word “take” should be guided by the term’s common-law meaning. Id. 
at 697 n.10. It explained that “Congress explicitly defined the operative 
term ‘take’ in the ESA, * * * thereby obviating the need for us to probe 
its meaning as we must probe the meaning of the undefined subsidiary 
term ‘harm.’ ” Ibid. The Court sustained as reasonable an Interior De- 
partment regulation that defined “harm” to include “significant habitat 
modification or degradation where it actually kills or injures wildlife by 
significantly impairing essential behavioral patterns, including breeding, 
feeding, or sheltering.” Id. at 691; see id. at 696-708. Similarly here, the 
judicial inquiry appropriately focuses on whether the contested Corps 
regulation reflects a permissible construction of the phrase “waters of the 
United States”—not whether the regulation accords with prior under- 
standings of a term (“navigable waters”) that Congress has expressly de- 
fined for purposes of the CWA. 

20 

guidelines must take into account the effect of discharges 
on “fish, shellfish, [and] wildlife,” 33 U.S.C. 1343(c)(1)(A), 
“changes in marine ecosystem diversity, productivity, and 
stability,” 33 U.S.C. 1343(c)(1)(B), and “esthetic, recreation, 
and economic values,” 33 U.S.C. 1343(c)(1)(C). See Riverside 
Bayview, 474 U.S. at 132 (characterizing the CWA’s purpose 
as the “[p]rotection of aquatic ecosystems”). In addition, 
EPA may veto or restrict the use of any site for the disposal 
of dredged or fill material when it determines that a 
discharge “will have an unacceptable adverse effect on muni- 
cipal water supplies, shellfish beds and fishery areas (includ- 
ing spawning and breeding areas), wildlife, or recreational 
areas.” 33 U.S.C. 1344(c). Because the potential for 
pollutant discharges to impair those values does not depend 
on the suitability of a water body for commercial traffic, the 
range of congressional objectives set forth in the text of the 
original Act strongly suggested that the CWA’s coverage is 
not confined by traditional concepts of navigability. 

13 

2. The clearest textual indication of the Act’s expansive 
scope, however, was added to the CWA in 1977. Section 
404(g)(1) of the Act (91 Stat. 1601) as amended provides in 
pertinent part: 

(1) 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 

13 “In the absence of contrary indication, [the Court] assume[s] that 
when a statute uses [an existing term of art], Congress intended it to have 
its established meaning.” McDermott Int’l, Inc. v. Wilander, 498 U.S. 337, 
342 (1991) (emphasis added); see Pet. Br. 16. As the italicized language 
makes clear, that principle of interpretation is a guide to congressional 
intent, not an inflexible rule of construction. “This Court has declined to 
follow any rule that a statutory term is to be given its common-law 
meaning, when that meaning is obsolete or inconsistent with the statute’s 
purpose.” Taylor v. United States, 495 U.S. 575, 594-595 (1990); see id. at 
595-596 (citing cases). 

21 

used, or are susceptible to use in their natural condition 
or by reasonable improvement as a means to transport 
interstate or foreign commerce * * * including wet- 
lands adjacent thereto) within its jurisdiction may sub- 
mit to the Administrator [of EPA] 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) (emphasis added). If the EPA Ad- 
ministrator approves a proposed state program, the Corps is 
divested of jurisdiction over “activities with respect to which 
a permit may be issued pursuant to such State program.” 33 
U.S.C. 1344(h)(2)(A). That provision would be meaningless if 
the waters subject to the Corps’ Section 404 jurisdiction 
included no waters “other than” those that meet traditional 
standards of navigability. 

14 

B. The Legislative History Of The 1972 Act And The 
1977 Amendments Supports The Corps’ Construction 
Of The Term “Waters Of The United States” 

1. Bills introduced in 1972 in both the House of 
Representatives and the Senate defined “navigable waters” 
as “the navigable waters of the United States.” See 2 
Environmental Policy Div., Library of Congress, Legislative 
History of the Water Pollution Control Act Amendments of 

14 Additionally, Section 404(g)(2) and (3) (91 Stat. 1601), as added in 
1977, provide that “the Secretary of the Interior, acting through the 
Director of the United States Fish and Wildlife Service,” shall be given 
notice of and an opportunity to comment on a proposed state permit 
program. 33 U.S.C. 1344(g)(2) and (3). That requirement assumes that 
protection of fish and wildlife is one of the goals of the Section 404 
program. The legislative history confirms that view. See S. Rep. No. 370, 
95th Cong., 1st Sess. 78 (1977) (“The committee amendments relating to 
the Fish and Wildlife Service are designed to (1) recognize the particular 
expertise of that agency and the relationship between its goals for fish and 
wildlife protection and the goals of the Water Act.”). 

22 

1972 at 1069, 1698 (1973). The House and Senate Com- 
mittees, however, expressed concern that the definition 
might be given an unduly narrow reading. Thus, the House 
Report observed: 

One term that the Committee was reluctant to define 
was the term “navigable waters.” The reluctance was 
based on the fear that any interpretation would be read 
narrowly. However, this is not the Committee’s intent. 
The Committee fully intends that the term “navigable 
waters” be given the broadest possible constitutional 
interpretation unencumbered by agency determinations 
which have been made or may be made for admini- 
strative purposes. 

H.R. Rep. No. 911, 92d Cong., 2d Sess. 131 (1972). The 
Senate Report stated that “[t]hrough a narrow interpreta- 
tion of the definition of interstate waters the implementation 
[of the] 1965 Act was severely limited. Water moves in 
hydrologic cycles and it is essential that discharge of 
pollutants be controlled at the source.” S. Rep. No. 414, 92d 
Cong., 1st Sess. 77 (1971). The Conference Committee de- 
leted the word “navigable” from the definition of “navigable 
waters,” broadly defining the term to include “the waters of 
the United States.” The Conference Report explained that 
the definition was intended to repudiate earlier limits on the 
reach of federal water pollution efforts: “The conferees fully 
intend that the term ‘navigable waters’ be given the 
broadest possible constitutional interpretation unencum- 
bered by agency determinations which have been made or 
may be made for administrative purposes.” S. Conf. Rep. 
No. 1236, 92d Cong., 2d Sess. 144 (1972). Those passages 
strongly suggest that the coverage of the Act does not 

23 

depend upon the suitability of particular waters for com- 
mercial traffic. 

15 

As petitioner notes (Br. 22-23), individual supporters of 
the CWA occasionally described the proposed Act’s coverage 
in terms of actual suitability for commercial transportation. 
Senator Muskie placed before the Senate an exhibit stating 
that the CWA would protect all waters that “form, in their 
ordinary condition by themselves or by uniting with other 
waters or other systems of transportation, such as highways 
or railroads, a continuing highway over which commerce is 
or may be carried on with other States or with foreign 
countries in the customary means of trade and travel in 
which commerce is conducted today.” 118 Cong. Rec. 33,699 
(1972). Representative Dingell stated that “[t]he gist of the 
Federal test is the waterway’s use as a highway, not 
whether it is part of a navigable interstate or international 
commercial highway.” Id. at 33,757 (citations and internal 
quotation marks omitted). Representative Dingell also 
stated, however, that the term “navigable waters” as used in 
the CWA “means all ‘the waters of the United States’ in a 
geographical sense. It does not mean ‘navigable waters of 
the United States’ in the technical sense as we sometimes 
see in some laws.” Id. at 33,756. He asserted as well that 

15 This Court has recognized that the CWA was “not merely another 
law ‘touching interstate waters’ ” but was “viewed by Congress as a ‘total 
restructuring’ and ‘complete rewriting’ of the existing water pollution 
legislation.” City of Milwaukee v. Illinois, 451 U.S. at 317; see also id. at 
318 (“Congress’ intent in enacting the [CWA] was clearly to establish an 
all-encompassing program of water pollution regulation.”); Middlesex 
County Sewerage Auth. v. National Sea Clammers Ass’n, 453 U.S. 1, 22 
(1981) (existing statutory scheme “was completely revised” by enactment 
of the CWA). Thus, even prior to the 1977 amendments, Congress’s 
evident intent to effect a comprehensive overhaul of the existing statutory 
scheme casts serious doubt on petitioner’s contention (Br. 15-16) that the 
CWA’s geographic coverage should be construed by reference to prior 
water protection laws. 

24 

“this new definition clearly encompasses all water bodies.” 
Id. at 33,757. Thus, while the remarks of individual 
legislators may create a degree of ambiguity on this point 
(by negative implication, rather than contradiction), the 1972 
legislative history taken as a whole indicates that Congress 
did not intend to restrict the Act’s coverage to waters that 
satisfy traditional standards of navigability. 

2. During the debates on the 1977 CWA amendments, 
the scope of the “navigable waters” subject to the Act—and, 
in particular, the propriety of the Corps’ assertion of 
jurisdiction over “isolated” waters—was a principal subject 
of congressional concern. The Corps’ interim final regula- 
tions, published in 1975, expressed the agency’s intent to 
assert jurisdiction (in Phase III of the phased-in approach) 
over waters not adjacent to traditional navigable waters. 
See 40 Fed. Reg. 31,321, 31,324-31,325 (1975); 33 C.F.R. 
209.120(d)(2)(i) (1976). 

16 A bill passed by the House of 
Representatives provided that for purposes of Section 404, 
the term “navigable waters” would be defined to mean “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. 10,420 (1977); see id. at 10,434 (passage of bill). 
The bill would have restricted the Corps’ regulatory author- 
ity under Section 404 to “navigable waters” so defined and 
their “adjacent wetlands.” Id. at 10,420. 

Critics of the Corps’ regulatory program pointed to the 
regulation of “isolated” waters as a reason to diminish the 

16 The final regulations, published in July 1977 during the pendency of 
the congressional debates (i.e., after passage of the initial House bill but 
before debate in the Senate), defined the term “waters of the United 
States” to include, inter alia, “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.” 
42 Fed. Reg. 37,144 (1977); 33 C.F.R. 323.2(a)(5) (1978). 

25 

Corps’ authority. Representative McKay stated that “[a]s it 
now stands, the corps has effective authority to require a 
permit application every time a dredge or fill activity is 
planned for any stream, ditch, or pond in the United States.” 
123 Cong. Rec. 10,418 (1977). Representative Abdnor 
similarly understood that under the existing regulations, 
“the Corps must regulate all waters—from the smallest to 
the largest, including isolated wetlands and lakes, inter- 
mittent streams, and prairie potholes.” Id. at 34,852 (exten- 
sion of remarks). He caused to be reprinted in the Con- 
gressional Record a letter from a Corps official explaining 
that “the ultimate test of these [regulatory] limits is a deter- 
mination that an activity affects interstate commerce in 
connection with a given water.” Ibid.; see also id. at 10,431 
(remarks of Rep. Wright). 

Unlike the House bill, the bill reported by the Senate 
Committee on Environment and Public Works did not re- 
strict the geographic scope of the Corps’ Section 404 juris- 
diction. As the Senate Report explained: 

To limit the jurisdiction of the [CWA] with reference 
to discharges of the pollutants of dredged or fill material 
would cripple efforts to achieve the act’s objectives. 

The committee amendment does not redefine navi- 
gable 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 corps program in the so-called phase I 
waters. Under the committee amendment, the corps 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 program for phase 
2 and 3 waters. 

26 

S. Rep. No. 370, supra, at 75. That passage demonstrates 
the Committee’s understanding of the Corps’ phased-in 
expansion of Section 404 jurisdiction in the 1975 regulations, 
which included tributaries of navigable waters in Phase II 
and “isolated” waters in Phase III. Instead of rejecting that 
approach, the Committee incorporated the existing regula- 
tory scheme into an amendment authorizing partial admini- 
stration of the Section 404 program by the States. The 
Senate bill also responded to the problem of perceived over- 
regulation by exempting specified activities—most notably 
certain agricultural and silvicultural activities—from Section 
404’s permit requirements. See id. at 75-77. 

As in the House of Representatives, debate on the bill 
reported by the Senate Committee reflected an under- 
standing that the Corps had asserted regulatory jurisdiction 
over “isolated” waters. Senator Bentsen asserted that the 
Committee bill “skirts the fundamental problem: the defini- 
tion of Federal jurisdiction in the regulation of dredge and 
fill activities. The program would still cover all waters of the 
United States, including small streams, ponds, isolated 
marshes, and intermittently flowing gullies.” 123 Cong. Rec. 
26,711 (1977). He proposed an amendment that would have 
restricted the geographic scope of the Corps’ authority in the 
same manner as the House bill—i.e., to navigable waters 
traditionally defined and their adjacent wetlands. See id. 
at 26,710-26,711. Senator Tower supported the Bentsen 
amendment as a means of addressing “a regulatory scheme 
which covers not just the rivers of the Nation but all surface 
waters and wetlands of the United States.” Id. at 26,722. On 
the other hand, Senator Stafford argued that it was unneces- 
sary to narrow the definition of “waters” because the Senate 
bill “insures continued protection of the Nation’s waters, but 
allows States to assume the primary responsibility for pro- 
tecting those lakes, rivers, streams, swamps, marshes and 
similar areas that lie outside the corps program in the so- 
called ‘Phase I waters.’ ” Id. at 26,714. 

27 

The Bentsen amendment was rejected by the full Senate. 
123 Cong. Rec. 26,728 (1977). The Conference Committee 
adopted the Senate approach, and “efforts to narrow the 
definition of ‘waters’ were abandoned.” Riverside Bayview, 
474 U.S. at 137. Congress instead acted to protect the pre- 
rogatives of the States by enacting 33 U.S.C. 1344(g), which 
established a mechanism by which the States may assert 
ultimate administrative control over the regulation of Phase 
II and III waters. See S. Conf. Rep. No. 830, 95th Cong., 1st 
Sess. 100-101 (1977); pp. 20-21, supra. 

17 As Senator Baker 
explained: 

[T]he conference bill retains the comprehensive juris- 
diction over the Nation’s waters exercised in the 1972 
Federal Water Pollution Control Act to control pollution 
to the fullest constitutional extent. A permit program 
will continue to regulate dredged or fill material dis- 
charged into all our Nation’s waters. 

123 Cong. Rec. 39,209 (1977); see also id. at 39,196 (Sen. 
Randolph) (1977 legislation in its final form “recognizes that 
there must be no basic gaps in the program for protection of 
wetlands and waterways from contamination”); id. at 39,210 
(Sen. Wallop) (explaining that “the conferees did not retreat 
from [Section 404’s] broad jurisdiction” but instead sought to 
alleviate over-regulation by, inter alia, “provid[ing] for 
the delegation of the permit program to the States” and 
“preempt[ing] many activities from permit requirements”). 

The 1977 legislative history thus makes three points clear. 
First, Congress was well aware of the Corps’ existing 
regulatory approach—including the Corps’ inclusion of 
“isolated” waters within the regulatory definition of “waters 
of the United States”—and debate in both Houses focused on 

17 The 1977 amendments also limited the scope of the Corps’ regulatory 
jurisdiction by exempting specified activities from the Section 404 pro- 
gram. 33 U.S.C. 1344(f); see S. Conf. Rep. No. 830, supra, at 100-101. 

28 

the propriety of that enforcement scheme. Second, a 
proposed statutory amendment that would have limited the 
“waters of the United States” to traditional navigable 
waters and their adjacent wetlands was passed by the House 
of Representatives and introduced in the Senate, but 
Congress ultimately declined to enact it. Third, Congress’s 
acquiescence in the existing regulatory definition was mani- 
fested not only by its failure to pass legislation superseding 
that definition, but also by its enactment of 33 U.S.C. 
1344(g), which presumed that the Corps’ Section 404 juris- 
diction encompassed waters “other than” navigable-in-fact 
waters and their adjacent wetlands. Cf. Bob Jones Univ. v. 
United States, 461 U.S. 574, 601 (1983) (inferring con- 
gressional acquiescence in agency interpretation from enact- 
ment of subsequent law that presumed the correctness of the 
agency’s view); FDA v. Brown & Williamson Tobacco Corp., 
120 S. Ct. 1291, 1313 (2000) (same). Congress’s refusal to 
overrule the Corps’ construction of the CWA as extending to 
“isolated” waters, together with its enactment of a new 
statutory provision that presumed the legitimacy of the 
existing regulatory definition, shows the reasonableness of 
the Corps’ approach. 

C. The Corps’ Construction Of The Statutory Term 
“Waters Of The United States” Is Entitled To De- 
ference 

1. “Th[e] view of the agency charged with administering 
the statute is entitled to considerable deference,” Chemical 
Mfrs. Ass’n v. NRDC, 470 U.S. 116, 125 (1985), and “a court 
may not substitute its own construction of a statutory pro- 
vision for a reasonable interpretation made by the admini- 
strator of an agency,” Chevron U.S.A. Inc. v. NRDC, 467 
U.S. 837, 844 (1984). The term “waters of the United States” 
is neither an established term of art (see p. 18 and note 10, 
supra) nor one with an obvious “plain meaning.” The choice 
among reasonable alternative constructions is therefore the 

29 

province of EPA and the Corps, the executive agencies 
charged with the Act’s administration. 

18 

In Riverside Bayview, this Court held that in light of the 
well-established rule of deference to administrative judg- 
ments, judicial “review [wa]s limited to the question whether 
it is reasonable, in light of the language, policies, and legis- 
lative history of the Act for the Corps to exercise juris- 
diction over wetlands adjacent to but not regularly flooded 
by rivers, streams, and other hydrographic features more 
conventionally identifiable as ‘waters.’ ” 
474 U.S. at 131. 

19 

The Court observed that “[f]aced with such a problem of de- 
fining the bounds of its regulatory authority, an agency may 
appropriately look to the legislative history and underlying 
policies of its statutory grants of authority.” Id. at 132. 
While recognizing that “[n]either of these sources provides 
unambiguous guidance for the Corps in this case,” the Court 
concluded that “together they do support the reasonableness 
of the Corps’ approach of defining adjacent wetlands as 
‘waters’ within the meaning of § 404(a).” Ibid. 

20 

18 As we explain above (see pp. 2-5, supra), although the Corps and 
EPA initially disagreed regarding the proper construction of the term 
“waters of the United States,” the two agencies have since promulgated 
substantially identical regulatory definitions. Compare 33 C.F.R. 
328.3(a)(3) with 40 C.F.R. 230.3(s)(3) and 232.2. EPA’s consistent view as 
to the broad scope of regulatory jurisdiction conferred by the CWA 
supports the Corps’ position. See note 1, supra (noting the primary role of 
EPA in the administration of the Act). Indeed, the interpretations of the 
two agencies coalesce for purposes of deference in this case. 

19 Petitioner’s suggestion (Br. 33 n.13) that deference is inappropriate 
in this case because the question presented goes to the scope of the Corps’ 
regulatory jurisdiction is directly contrary to Riverside Bayview. See also 
CFTC v. Schor, 478 U.S. 833, 845 (1986) (holding deference appropriate 
notwithstanding “statutory interpretation-jurisdictional” nature of issue). 

20 The Court reached that conclusion, moreover, despite its recognition 
that “[o]n a purely linguistic level, it may appear unreasonable to classify 
‘lands,’ wet or otherwise, as ‘waters.’ ” 474 U.S. at 132. The Court 
explained that “the evident breadth of congressional concern for pro- 

30 

2. Petitioner contends (Br. 32) that “[t]he CWA’s juris- 
dictional terms * * * are not ambiguous when read in light 
of settled meanings established in this Court’s decisions.” 
Reliance on the “settled meaning[]” of the term “navigable 
waters” is flatly inconsistent, however, with 33 U.S.C. 
1344(g)(1), which assumes that federal jurisdiction exists 
over waters “other than” those actually or potentially 
suitable for commercial traffic. See pp. 20-21, supra. Peti- 
tioner’s plain language argument is also at odds with 
Riverside Bayview, which sustained the Corps’ assertion of 
jurisdiction over adjacent wetlands, notwithstanding the 
Court’s recognition that such areas are neither “navigable” 
nor “waters” under usual understandings of those terms. 
See 474 U.S. at 132-133. 

21 

Elsewhere, petitioner appears to acknowledge (Br. 16-17) 
that the Corps’ jurisdiction extends to waters (including 

tection of water quality and aquatic ecosystems suggests that it is 
reasonable for the Corps to interpret the term ‘waters’ to encompass 
wetlands adjacent to waters as more conventionally defined.” Id. at 133. 
In the instant case, by contrast, there is no dispute that the ponds on 
petitioner’s land are “waters” within the usual understanding of that term. 

21 Riverside Bayview is also highly instructive with respect to several 
subsidiary questions implicated here. The Court in Riverside Bayview 
held that the Corps’ construction of the term “waters of the United 
States” is entitled to deference, 474 U.S. at 131; that “the term ‘navigable’ 
as used in the Act is of limited import,” id. at 133; that the potential 
applicability of the Corps’ rule to some waters lacking ecological signifi- 
cance is unproblematic because the Corps can grant a permit in such cases, 
id. at 135 n.9; that the history of the 1977 amendments is relevant in 
construing the term “waters of the United States” because “a refusal by 
Congress to overrule an agency’s construction of legislation is at least 
some evidence of the reasonableness of that construction, particularly 
where the administrative construction has been brought to Congress’ 
attention through legislation specifically designed to supplant it,” id. at 
137; and that the language of 33 U.S.C. 1344(g)(1) bears on the proper 
interpretation of the term “waters of the United States” because the two 
provisions should be construed in pari materia, 474 U.S. at 138 & n.11. 

31 

wetlands) that are not themselves actually or potentially 
suitable for navigation, but that feed through surface con- 
nections to traditional navigable waters. On that theory, the 
term “waters of the United States” would encompass (a) 
traditional navigable waters, (b) tributaries of those waters, 
and (c) wetlands adjacent to waters in either of the first two 
categories. Petitioner contends (Br. 17) that such waters are 
different in kind from “isolated” waters, even those whose 
destruction or degradation can be expected to affect inter- 
state commerce. But the basis for that distinction is unclear. 
The established meaning of the phrase “navigable waters” 
cannot provide the answer, since that term of art would 
exclude non-navigable tributaries and all wetlands. Nor 
does the “plain meaning” of the phrase “waters of the United 
States” compel the line of demarcation that petitioner advo- 
cates. 

Thus, “Congress has not directly addressed the precise 
question at issue.” Chevron, 467 U.S. at 843. Faced with 
that textual ambiguity, the Corps and EPA have devised a 
jurisdictional standard that turns on the prospect of inter- 
state effects resulting from water pollution, rather than on a 
particular causal mechanism (surface water connections to 
traditional navigable waters) by which those effects may be 
produced. That approach is entirely reasonable, since 
pollution of even “isolated” waters can impair the interests 
that the CWA was intended and declared by Congress to 
protect. See pp. 19-20, supra. 

22 The propriety of the 

22 Petitioner’s only basis for distinguishing between a non-navigable 
tributary and a non-navigable pond is that pollution of the tributary may 
ultimately degrade the quality of traditional navigable waters. See Pet. 
Br. 16-17. That argument assumes that Congress’s only objective in the 
CWA was to protect the quality of traditional navigable waters. Under 
that theory, protection of non-navigable tributaries and adjacent wetlands 
is not an end in itself, but simply the fortuitous result of Congress’s effort 
to protect a much narrower category of waters. The breadth of the Act’s 
declared purposes, however—which include protection and propagation of 

32 

agencies’ regulatory definition is further supported by the 
steps that Congress took (and declined to take) in 1977 after 
the Corps’ approach was brought to its attention. See pp. 
24-28, supra; Riverside Bayview, 474 U.S. at 137. 

3. Petitioner errs in contending (Br. 33) that “[t]he 
Corps’ claim to deference raises serious problems of delega- 
tion of lawmaking authority.” This Court has long recog- 
nized that Congress in exercising its Commerce Clause 
authority may “le[ave] it to an administrative board or 
agency to determine whether the activities sought to be 
regulated or prohibited have” the requisite effect on com- 
merce. United States v. Darby, 312 U.S. 100, 120 (1941). 

23 

Nor is there merit to petitioner’s contention (Br. 33) that 
“Congress focused on human navigation, not the episodic 
migration of waterfowl.” To the contrary, the “Con- 
gressional declaration of goals and policy” (33 U.S.C. 1251) 
that begins the CWA includes “the protection and pro- 
pagation of fish, shellfish, and wildlife,” 33 U.S.C. 
1251(a)(2), 

24 but makes no reference to the furtherance of 

fish and wildlife, see 33 U.S.C. 1251(a)(2)—strongly suggests that Con- 
gress regarded protection of such waters as independently desirable. In 
any event, degradation of “isolated” waters may also impair the quality of 
traditional navigable waters. See note 10, supra. 

23 For essentially the same reason, there is no merit to petitioner’s 
reliance (Br. 26-28) on the canon that ambiguous statutes will be construed 
to avoid constitutional difficulties. The Corps has construed the term 
“waters of the United States” to encompass all waters physically located 
within this country (including the territorial seas) that bear a sufficient 
nexus to interstate commerce to support the exercise of federal regulatory 
jurisdiction. Since the Corps has defined the scope of its authority by 
reference to constitutional limits on federal power, the pertinent regula- 
tion (33 C.F.R. 328.3(a)(3)) cannot be subject to facial constitutional attack. 

24 Petitioner errs in asserting (Br. 24) that “[n]o one in 1977 so much as 
mentioned migratory birds as a basis for Corps jurisdiction.” The 1977 
legislative history includes repeated references to the need for compre- 
hensive protection of the country’s wetlands and other waters as habitat 
for birds and other wildlife. See S. Rep. No. 370, supra, at 10 (waters 

33 

navigation or to the prevention of impediments to com- 
mercial traffic. Compare Rivers and Harbors Appropriation 
Act of 1899, § 10, 33 U.S.C. 403 (“The creation of any ob- 
struction not affirmatively authorized by Congress, to the 
navigable capacity of any of the waters of the United States 
is prohibited.”). 

4. Finally, the Corps’ exercise of regulatory jurisdiction 
over isolated waters does not (as petitioner contends, see Br. 
28-31) threaten the federal-state balance. The Corps in 
evaluating permit applications recognizes that “[t]he pri- 
mary responsibility for determining zoning and land use 
matters rests with state, local and tribal governments,” and 
the agency “will normally accept decisions by such govern- 
ments on those matters unless there are significant issues of 
overriding national importance.” 33 C.F.R. 320.4(j)(2). Such 
issues of national significance include “preservation of 
special aquatic areas, including wetlands, with significant 
interstate importance.” Ibid. Of course, the regulatory 
scheme contemplates that projects approved by state and 
local authorities may be denied a federal permit if they 
threaten significant national interests. But it is neither 
unusual nor inappropriate for a federal agency’s exercise of 
its authority to have some preemptive effects. See, e.g., City 

covered by Section 404 “provide nesting areas for a myriad of species of 
birds and wildlife”); 123 Cong. Rec. 10,415 (1977) (Rep. Lehman) (Section 
404 as interpreted in the Corps’ regulations “is a key to the protection of 
drinking supplies, finfish and shellfish spawning grounds, wildlife nesting 
and breeding areas, and countless esthetic and recreation benefits”); id. at 
26,697 (Sen. Muskie) (Section 404 is necessary to protect wetlands be- 
cause, inter alia, they “provide nesting areas for a myriad of species of 
birds and wildlife”); id. at 26,701 (Sen. Stafford) (Section 404 is “essential 
to the preservation of migratory and resident fish, bird and other animal 
populations”); id. at 26,716 (Sen. Chafee) (“wetlands provide the breeding 
and feeding areas for our migratory waterfowl”); id. at 26,719 (Sen. Baker) 
(wetlands important as, inter alia, “essential nesting and wintering areas 
for waterfowl”). Cf. note 14, supra. 

34 

of N.Y. v. FCC, 486 U.S. 57, 63-64 (1988). And a decision to 
deny a permit is, of course, subject to judicial review. 

25 

Far from preserving the existing balance between federal 
and state authority, petitioner’s construction of the Act 
would substantially alter the manner in which water pollu- 
tion is currently addressed. The Corps’ “other waters” regu- 
lation has been in effect for more than 20 years. Congress 
considered but declined to enact legislation that would have 
superseded that rule (see pp. 24-28, supra), and this Court 
has recognized that “the Act applies to virtually all surface 
water in the country.” International Paper Co. v. Ouellette, 
479 U.S. 481, 486 (1987); see id. at 486 n.6 (“While the Act 
purports to regulate only ‘navigable waters,’ this term has 
been construed expansively to cover waters that are not 
navigable in the traditional sense.”); id. at 492 (“The Act 
applies to all point sources and virtually all bodies of 
water.”). The courts of appeals have uniformly agreed, 
moreover, that Congress intended the geographic scope of 
the CWA to extend to the maximum extent permissible 

25 As we explain above (see pp. 20-21, supra), moreover, the CWA 
provides a mechanism by which state authorities may assume responsi- 
bility for the protection of 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.” 33 U.S.C. 
1344(g)(1). If officials in a particular State regard the Corps’ exercise of 
jurisdiction over isolated waters as an intrusion on state prerogatives, the 
Act provides a means of adjusting the division of regulatory responsi- 
bilities between federal and state authorities. See note 7, supra. Addi- 
tional protection of state interests is provided by 33 C.F.R. 323.2(h)(2), 
which authorizes the Corps to issue a general permit for a category of 
activities when “[t]he general permit would result in avoiding unnecessary 
duplication of regulatory control exercised by another Federal, State, or 
local agency provided it has been determined that the environmental 
consequences of the action are individually and cumulatively minimal.” 

35 

under the Commerce Clause. 

26 Although the Act explicitly 
preserves the States’ authority to regulate pollutant dis- 
charges within their borders, see 33 U.S.C. 1370, and indeed 
authorizes the States to assume responsibility for admin- 
istering the Section 404 program with respect to Phase II 
and III waters, see 33 U.S.C. 1344(g), the States in fash- 
ioning their own regulatory schemes have acted against a 
background assumption of comprehensive federal oversight. 
Judicial invalidation of the “other waters” regulation at this 
late date can therefore scarcely be regarded as a means of 
preserving the federal-state balance. 

27 

26 See, e.g., United States v. Hartsell, 127 F.3d 343, 348 & n.1 (4th Cir. 
1997), cert. denied, 523 U.S. 1030 (1998); United States v. Tull, 769 F.2d 
182, 184 (4th Cir. 1985), rev’d on other grounds, 481 U.S. 412 (1987); see 
also United States v. Eidson, 108 F.3d 1336, 1341 (11th Cir.), cert. denied, 
522 U.S. 899 and 1004 (1997); United States v. Pozsgai, 999 F.2d 719, 731 
(3d Cir. 1993), cert. denied, 510 U.S. 1110 (1994); Leslie Salt Co. v. United 
States, 896 F.2d 354, 357 (9th Cir. 1990), cert. denied, 498 U.S. 1126 (1991); 
Quivira Mining Co. v. United States EPA, 765 F.2d 126, 129-130 (10th 
Cir. 1985), cert. denied, 474 U.S. 1055 (1986); Avoyelles Sportsmen’s 
League, Inc. v. Marsh, 715 F.2d 897, 914-915 (5th Cir. 1983). But cf. 
Exxon Corp. v. Train, 554 F.2d 1310, 1317-1331 (5th Cir. 1977) (“waters of 
the United States” does not cover groundwater). 

27 Indeed, petitioner’s interpretation of the CWA would constrain 
federal regulatory authority more greatly than the rejected 1977 House 
bill and parallel Bentsen amendment would have done. Those legislative 
proposals would have narrowed the definition of navigable waters only 
with respect to the Corps’ permitting authority over discharges of 
dredged and fill material under Section 404. “[T]he House bill would have 
left intact the existing definition of ‘navigable waters’ for purposes of § 301 
of the Act, which generally prohibits discharges of pollutants into 
navigable waters.” Riverside Bayview, 474 U.S. at 137-138. Senator 
Bentsen emphasized that “our amendment deals with section 404 * * * 
which regulates dredging and filling activities * * *. Section 404 does not 
speak to toxic discharges, * * * and we do not propose to change the law 
and permit any relaxation of our efforts to clamp down on the dumping of 
sewage or ‘toxic spoil’ or any other toxic discharges in even the smallest 
creek in this Nation.” 123 Cong. Rec. 26,712 (1977). Petitioner’s 

36 

II. USE OF PETITIONER’S WATERS BY MIGRA- 
TORY BIRDS FOR HABITAT PROVIDES A CON- 
STITUTIONALLY SUFFICIENT BASIS FOR 
FEDERAL REGULATION UNDER THE COM- 
MERCE CLAUSE 

This Court has identified “three broad categories of activ- 
ity that Congress may regulate under its commerce power”: 
(1) the use of the channels of interstate commerce; (2) the 
instrumentalities of interstate commerce, or persons and 
things in interstate commerce; and (3) intrastate activities 
that “substantially affect” interstate commerce. Lopez, 514 
U.S. at 558-559 (citing, inter alia, Perez v. United States, 402 
U.S. 146, 150 (1971)). Under Lopez’s third category, Con- 
gress may regulate intrastate activities that do not 
individually have a pronounced effect on interstate com- 
merce if the aggregate effect of the class of activities is 
substantial. 

28 Thus, in Wickard v. Filburn, 317 U.S. 111 
(1942), this Court upheld the application of the Agricultural 
Adjustment Act of 1938 to the production of wheat con- 
sumed by the grower. That one such person’s production of 

construction of the CWA, by contrast, would threaten to deprive EPA of 
jurisdiction under Section 402 of the Act to regulate discharges of toxic 
chemicals into isolated waters, since EPA’s jurisdiction is likewise 
confined to “waters of the United States.” See 33 U.S.C. 1311(a), 1342, 
1362(7), 1362(12). In addition, the 1977 House bill and Bentsen 
amendment would have authorized the Corps to regulate “the discharge of 
dredged or fill material in waters other than navigable waters and in 
wetlands other than adjacent wetlands” pursuant to an agreement with 
the Governor of the relevant State. 123 Cong. Rec. 10,421 (1977); id. at 
26,710; see H.R. Rep. No. 139, 95th Cong., 1st Sess. 23 (1977). 

28 This Court has applied such an aggregation approach in, e.g., Hodel 

v. Indiana, 452 U.S. 314, 324-325 (1981); Hodel v. Virginia Surface Mining 
& Reclamation Ass’n, 452 U.S. 264 (1981); Perez v. United States, 402 U.S. 
at 154; Katzenbach v. McClung, 379 U.S. 294, 301 (1964); Polish Nat’l 
Alliance v. NLRB, 322 U.S. 643, 648 (1944); Wickard v. Filburn, 317 U.S. 
111, 127-129 (1942); United States v. Darby, 312 U.S. at 123. 

37 

wheat may have had trivial effects upon commerce was of no 
import, the Court held, “where, as here, his contribution, 
taken together with that of many others similarly situated, is 
far from trivial.” 317 U.S. at 127-128. 

This Court has made clear, however, that the Commerce 
Clause does not grant Congress plenary authority to regu- 
late intrastate conduct based on its likely effects on the 
national economy. See Lopez, supra; United States v. 
Morrison, 120 S. Ct. 1740 (2000). In articulating the limits on 
the third category of permissible Commerce Clause regula- 
tion, the Court has attached substantial importance to 
whether the regulated activity is of a commercial character. 
See Morrison, 120 S. Ct. at 1749-1750. The Court has 
also emphasized that limits on Commerce Clause authority 
serve ultimately to ensure that Congress does not assume a 
general police power or usurp functions more appropriately 
exercised by the States. Id. at 1752-1754. 

The Corps’ exercise of regulatory authority in this case 
falls well within constitutional limits. Because migratory 
birds are a shared resource of the several States, their pro- 
tection has traditionally been regarded as a task most appro- 
priately performed by the national government. The 
activities for which petitioner sought a Section 404 permit 
are of a commercial character, and the waters involved were 
determined, after extensive analysis, to furnish important 
habitat for numerous migratory bird species. Finally, the 
destruction of migratory bird habitat can be expected 
to have a substantial aggregate effect on interstate com- 
merce. 

29 

29 In Sweet Home this Court sustained, against a statutory challenge, 
an Interior Department regulation that construed the Endangered 
Species Act of 1973 (ESA) to prohibit habitat modification on private land 
that would kill or injure members of a listed species. See note 12, supra. 
No Member of the Court suggested that the ESA, so construed, might 
exceed Congress’s powers under the Commerce Clause. The Fourth Cir- 
cuit recently held that restrictions on takings of endangered red wolves 

38 

A. The Protection Of Migratory Bird Habitat Furthers A 

Governmental And Public Interest That Has Long 
Been Recognized To Be A Matter Of National Con- 
cern 

1. In Lopez and Morrison, this Court emphasized that 
while congressional power under the Commerce Clause is 
broad, it is subject to judicially enforceable limits. The 
Court stressed that “[t]he Constitution requires a distinction 
between what is truly national and what is truly local,” 
Morrison, 120 S. Ct. at 1754, and it expressed “the concern 

* * * that Congress might use the Commerce Clause to 
completely obliterate the Constitution’s distinction between 
national and local authority,” id. at 1752. The federal 
laws struck down in those cases were intended to further 
governmental interests—protection of the educational pro- 
cess, see Lopez, 514 U.S. at 564-566, and the “suppression of 
violent crime,” see Morrison, 120 Ct. at 1754—that have as 
an historical matter been principally entrusted to the States. 
That the evils addressed by those laws might also have 
ultimate effects on the national economy was not, the Court 

imposed by the ESA and implementing regulations are a permissible 
exercise of Commerce Clause authority. See Gibbs v. Babbitt, 214 F.3d 
483 (4th Cir. 2000) (Wilkinson, C.J.). The court observed that the regu- 
lated activity is properly regarded as economic in nature because “[t]he 
protection of commercial and economic assets is a primary reason for 
taking the wolves,” id. at 492, even though the statute and rules do not 
require proof of an economic motive in a particular case. The court also 
stated that “[t]he relationship between red wolf takings and interstate 
commerce is quite direct—with no red wolves, there will be no red wolf 
related tourism, no scientific research, and no commercial trade in pelts.” 
Ibid. The court of appeals rejected the plaintiffs’ contention that the ESA 
and regulations were inconsistent with “the historic roles of federal and 
state authority,” id. at 499, explaining that “[i]n contrast to gender-moti- 
vated violence or guns in school yards, the conservation of scarce natural 
resources is an appropriate and well-recognized area of federal regulation. 
The federal government has been involved in a variety of conservation 
efforts since the beginning of this century.” Id. at 500. 

39 

held, a sufficient basis for federal regulation under the 
Commerce Clause. 

By contrast, “[t]he protection of migratory birds has long 
been recognized as ‘a national interest of very nearly the 
first magnitude.’ ” 
North Dakota v. United States, 460 U.S. 

300, 309 (1983) (quoting Missouri v. Holland, 252 U.S. 416, 
435 (1920) (Holmes, J.)). The Court in Holland explained 
that the protection of migratory birds is an interest 
inherently unsuited to effective vindication by the States: 

[Migratory birds] can be protected only by national 
action in concert with that of another power. 

[30] The 
subject matter is only transitorily within the State and 
has no permanent habitat therein. But for the treaty 
and the statute there soon might be no birds for any 
powers to deal with. We see nothing in the Constitution 
that compels the Government to sit by while a food 

30 Missouri v. Holland upheld the Migratory Bird Treaty Act, a 
federal law enacted pursuant to the treaty power as a means of imple- 
menting an agreement between the United States and Great Britain for 
the protection of birds that migrated between the United States and 
Canada. See 252 U.S. at 431-433. The Court observed that 

[a]n earlier act of Congress that attempted by itself and not in 
pursuance of a treaty to regulate the killing of migratory birds within 
the States had been held bad in the District Court. United States v. 
Shauver, 214 Fed. 154. United States v. McCullagh, 221 Fed. 288. 
Those decisions were supported by arguments that migratory birds 
were owned by the States in their sovereign capacity for the benefit 
of their people, and that under cases like Geer v. Connecticut, 161 
U.S. 519, this control was one that Congress had no power to displace. 

Id. at 432. The Court concluded that “[w]hether the two cases cited [i.e., 
Shauver and McCullagh] were decided rightly or not they cannot be ac- 
cepted as a test of the treaty power.” Id. at 433. In Douglas v. Seacoast 
Prods., Inc., 431 U.S. 265, 283-285 (1977), the Court held that a State’s 
purported “ownership” of wildlife within its borders did not provide a 
basis on which the State could prohibit federally licensed vessels from 
fishing in the State’s waters. Two Terms later Geer was overruled. See 
Hughes v. Oklahoma, 441 U.S. 322, 335-336 (1979). 

40 

supply is cut off and the protectors of our forests and our 
crops are destroyed. It is not sufficient to rely upon the 
States. 

Holland, 252 U.S. at 435 (emphasis added). Thus, activities 
that threaten the well-being of migratory birds—like activi- 
ties that pollute interstate waters—are a traditional and 
appropriate subject of federal regulation. Like water 
flowing in an interstate river, migratory birds constitute a 
natural resource of substantial economic importance that has 
no permanent locus in a single State. Because “the subject 
matter is only transitorily within the State” where the regu- 
lated activity occurs, the birds are appropriately regarded as 
a shared resource of the several States. The appropriate 
balance between species protection and other goals therefore 
should not be entrusted to the sole judgment of state 
authorities. 

2. The protection of suitable habitat is an integral feature 
of federal efforts to protect the well-being of migratory 
birds. See North Dakota, 460 U.S. at 309-310 (“A series of 
treaties dating back to 1916 obligates the United States to 
preserve and protect migratory birds through the regulation 
of hunting, the establishment of refuges, and the protection 
of bird habitats.”); compare Sweet Home, 515 U.S. at 699-700 
(recognizing that loss of habitat for endangered species could 
cause their extinction). More than 50% of aquatic migratory 
bird habitat has been lost since the Nation’s founding. 
Thomas Dahl, U.S. Dep’t of the Interior, Wetlands Losses in 
the United States 1780’s to 1980’s at 1 (1990). That loss has 
greatly reduced the population of migratory birds. See 
Waterfowl Plan 9; Hoffman Homes, Inc. v. Administrator, 
United States Envtl. Protection Agency, 999 F.2d 256, 261 
(7th Cir. 1993) (noting that the “cumulative loss of wetlands 
has reduced populations of many bird species and conse- 
quently the ability of people to hunt, trap, and observe those 
birds”); Fund for Animals v. Frizzell, 530 F.2d 982, 986 

41 

(D.C. Cir. 1975) (“Research and experience have demon- 
strated that habitat is the key factor limiting most, if not all, 
migratory bird populations.”) (citation omitted). 

31 “Isolated” 
waters play a crucial role as habitat for numerous aquatic 
species, including migratory waterfowl and other migratory 
birds. 

32 

3. For the reasons stated above, recognition of federal 
power to prevent the destruction of migratory bird habitat 
presents no danger that “Congress might use the Commerce 
Clause to completely obliterate the Constitution’s distinction 
between national and local authority.” Morrison, 120 S. Ct. 
at 1752. In recognizing the “national interest” in the protec- 
tion of migratory birds, the Court in Missouri v. Holland did 
not simply recite the obvious fact that migratory birds are 

31 Wetlands “provide habitat essential for the breeding, spawning, 
nesting, migration, wintering and ultimate survival of * * * migratory 
birds.” Emergency Wetlands Resources Act of 1986, 16 U.S.C. 3901(a)(2). 
See also Water Bank Act, 16 U.S.C. 1301 (declaring it to be “in the public 
interest to preserve, restore, and improve the wetlands of the Nation 

* * * to preserve and improve habitat for migratory waterfowl.”). The 
North American Waterfowl Management Plan, signed by the United 
States, Mexico, and Canada, as part of the implementation of the Migra- 
tory Bird Treaty Act, recognizes the crucial importance of protecting 
migratory bird habitats, including ponds and wetlands. Waterfowl Plan 1, 
9-11. Wetlands provide essential breeding and resting sites for more than 
50% of the Nation’s migratory bird species. Dahl & Johnson, supra, at 3. 

32 See National Research Council, Wetlands: Characteristics and 
Boundaries 9 (1995) (“isolated” wetlands “may even perform some unique 
or particularly valuable functions, including maintenance of water quality 
and the support of waterfowl.”); id. at 156 (“Small, shallow wetlands that 
are isolated from rivers are frequently important to waterfowl.”). Shallow 
“isolated” waters typically thaw early in the season, providing important 
habitat for migratory birds. Ibid. Prairie potholes—isolated, water-filled 
glacial depressions prevalent in the Plains States—provide substantial 
support of waterfowl and wading birds. Ibid. As much as half the water- 
fowl of North America originate from the pothole region. Id. at 280-281; 
see also North Dakota, 460 U.S. at 304 & n.4 (discussing importance of 
prairie potholes). 

42 

present throughout the country, or that the cumulative 
nationwide impact of migratory bird takings is substantial. 
Rather, the Court emphasized that the protection of migra- 
tory birds is principally entrusted to the national govern- 
ment because it is a task inherently unsuited to piecemeal 
accomplishment. The Corps’ assertion of regulatory juris- 
diction over “isolated” waters used as migratory bird habitat 
is thus fully in keeping with traditional conceptions of the 
“distinction between what is truly national and what is truly 
local.” Morrison, 120 S. Ct. at 1754. 

33 

33 Petitioner contends (Br. 34-36) that the Corps did not recognize until 
1985 that the use of waters as habitat for migratory birds provided a basis 
for the exercise of federal regulatory jurisdiction. That is not the case. As 
early as 1975, when the Corps first announced its “phased in” approach 
(see p. 4 & note 2, supra), it stated that “[w]etlands considered to perform 
functions important to the public interest include * * * [w]etlands which 
serve important natural biological functions, including food chain pro- 
duction, general habitat, and nesting, spawning, rearing and resting sites 
for aquatic or land species.” 40 Fed. Reg. 31,328 (1975). The issue in the 
1985 oversight hearings on which petitioner relies (see Br. 35) was the 
manner in which the Corps had been exercising its jurisdiction— 
specifically, by requiring evidence of actual (and in some cases extensive) 
use by migratory birds. See Oversight Hearings on Section 404 of the 
Clean Water Act: Hearings Before the Subcomm. on Envtl. Pollution of 
the Senate Comm. on Env’t and Pub. Works, 99th Cong., 1st Sess. 122-123 
(1985) (1985 Hearings). Participants at the hearings recognized that in 
Utah v. Marsh, 740 F.2d 799, 804 (10th Cir. 1984), the Corps had success- 
fully asserted jurisdiction over an intrastate lake based in part on its use 
by migratory birds. 1985 Hearings 121, 208. The Acting Assistant Secre- 
tary of the Army for Civil Works assured the subcommittee that “[t]he 
Corps has been making jurisdictional determinations on isolated wetlands 
in the same way since publication of our 1977 regulations,” and that a 
particularly controversial decision not to exercise jurisdiction over a pond 
in Texas was simply based on the fact that use by migratory birds in that 
instance was “trivial.” Id. at 210-211; see also id. at 123. In any event, the 
Corps’ assertion of regulatory jurisdiction over waters used by migratory 
birds as habitat is a valid exercise of Commerce Clause authority, re- 
gardless of when (or why) the Corps initially focused its attention on that 
category of waters. 

43 

B. The Instant Case Involves Commercial Activity 

Having A Substantial Impact On Actual Migratory 

Bird Habitat 

1. The proposed activity for which petitioner sought a 
federal permit—the filling of ponds in order to construct a 
municipal landfill—is plainly of a commercial nature. This 
Court has repeatedly held that state and local laws govern- 
ing the construction and operation of landfills constitute 
regulations of commercial activity and are subject to scru- 
tiny under the Commerce Clause. See, e.g., C&A Carbone, 
Inc. v. Town of Clarkstown, 511 U.S. 383, 389-394 (1994); 
Oregon Waste Sys., Inc. v. Department of Envtl. Quality, 
511 U.S. 93, 98-108 (1994); City of Philadelphia v. New 
Jersey, 437 U.S. 617, 621-629 (1978). Just as “the rental of 
real estate * * * is unquestionably” a commercial use of 
property, Jones v. United States, 120 S. Ct. 1904, 1911 (2000), 
the dredge and fill activity at issue in this case amounts to 
commercial development. 

As the case comes to this Court, it is undisputed that “the 
filling of the 17.6 acres would have an immediate effect on 
migratory birds that actually use the area as a habitat.” Pet. 
App. 10a. The United States Fish and Wildlife Service 
(FWS) conducted an extensive analysis, see Fed. C.A. App. 
190-198 (A.R. 16,382-16,390), and concluded that “[b]ecause 
of its value to migratory birds, we do not believe this site is 
an appropriate place to site a landfill.” Id. at 197 (A.R. 
16,389). As the Corps’ decision documents make clear, the 
use of the ponds by migratory birds was not simply a 
jurisdictional trigger; rather, the potential impact of the 
proposed landfill on numerous bird species was a central 
justification for the denial of petitioner’s permit application. 
See Fed. C.A. App. 32-40 (A.R. 15,692-15,700); pp. 8-9, supra. 
Although petitioner’s district court complaint contested the 
merits of the Corps’ permitting decision, see Pet. App. 1a-2a, 
that challenge was abandoned on appeal, see id. at 4a, and 

44 

the court of appeals accordingly “accept[ed] as true the 
Corps’ factual findings with regard to [petitioner’s] permit 
application, including the crucial finding that the waters of 
this site were a habitat for migratory birds.” Id. at 5a. 

2. Notwithstanding the commercial character of peti- 
tioner’s own proposed activities, and the undisputed impact 
of those activities on migratory birds, petitioner’s argument 
focuses largely on hypothetical situations not before the 
Court. Thus, petitioner emphasizes (see Br. 37-38) that the 
Corps’ Section 404 regulations would encompass some dis- 
charges of dredged and fill material undertaken for non- 
economic motives. Petitioner also asserts that since “migra- 
tory birds will alight almost anywhere,” the effect of the 
Corps’ regulatory approach is to assert federal jurisdiction 
over all isolated waters. Pet. Br. 42; see also id. at 40. 

This Court’s analysis of the constitutional question, how- 
ever, should focus on the circumstances actually before the 
Court. Cf. Salinas v. United States, 522 U.S. 52, 60-61 (1997) 
(holding that 18 U.S.C. 666(a)(1)(B) is constitutional as ap- 
plied to a bribery offense that threatens the integrity of the 
relevant federal program, and affirming the defendant’s 
conviction on that basis, without addressing the consti- 
tutionality of other potential applications of the statute). In 
part that is because “[t]his case involves an as-applied, not a 
facial challenge” (Pet. Br. 31 n.12) to a site-specific admini- 
strative decision. Perhaps the more fundamental point, 
however, is that (as we emphasize above) the Corps’ deter- 
mination that particular activities fall within its permitting 
authority does not mean that such activities are prohibited. 
It simply means that the Corps will scrutinize the likely 
impacts of a project on federal interests (including the pro- 
tection of migratory birds) before deciding whether the 
project may go forward. 

34 

34 As the Court in Riverside Bayview explained: 

45 

There is also every reason to believe that the instant case 
is representative of those in which the use of waters as 
habitat for migratory birds is invoked as a basis for the 
Corps’ denial of a Section 404 permit. 

35 The loss of migratory 

[I]t may well be that not every adjacent wetland is of great impor- 
tance to the environment of adjoining bodies of water. But the 
existence of such cases does not seriously undermine the Corps’ 
decision to define all adjacent wetlands as “waters.” * * * That the 
definition may include some wetlands that are not significantly 
intertwined with the ecosystem of adjacent waterways is of little 
moment, for where it appears that a wetland covered by the Corps’ 
definition is in fact lacking in importance to the aquatic environment 
—or where its importance is outweighed by other values—the Corps 
may always allow development of the wetland for other uses simply 
by issuing a permit. 

474 U.S. at 135 n.9. Justice O’Connor’s concurring opinion in Sweet Home 
reflects a similar mode of analysis. In reviewing the Interior Depart- 
ment’s regulatory definition of the ESA term “harm” (see note 12, supra), 
Justice O’Connor acknowledged that “[o]ne can doubtless imagine 
questionable applications of the regulation that test the limits of the 
agency’s authority.” 515 U.S. at 714 (O’Connor, J., concurring). She 
agreed that the rule should be upheld, however, because she found it 
“clear that the regulation does not on its terms exceed the agency’s 
mandate, and that the regulation has innumerable valid habitat-related 
applications.” Ibid. 

35 The Corps has recognized that some features containing water are 
not ordinarily covered by the CWA, specifically citing artificial basins 
used for stock watering and irrigation, swimming pools, and temporary 
water-filled depressions created by construction projects. 51 Fed. Reg. 
41,206, 41,217 (1986). Furthermore, the great majority of activities that do 
involve discharges of dredged or fill material into waters of the United 
States are currently authorized by general permits, issued on a nationwide 
or regional basis pursuant to 33 U.S.C. 1344(e). The Corps has informed 
us that in fiscal year 1999, it received approximately 60,000 applications 
for Section 404 permits, of which approximately 85% were considered 
under some type of general permit (either Nationwide or Regional 
General Permits). Many of the “trivial” examples cited by petitioners (Br. 
37-38) are covered by nationwide permits. For example, NWP #18 author- 
izes discharges up to 0.1 acre in waters of the United States; NWP #29 

46 

bird habitat has been caused overwhelmingly by commercial 
activities—agricultural and industrial development, urbani- 
zation, and other commercial development. 

36 See Waterfowl 

Plan 9; Dahl & Johnson, supra, at 2. 
37 A judicial focus on the 

authorizes discharges up to 0.25 acre for construction and expansion of 
single-family homes, subject to certain conditions to ensure that the 
individual and cumulative environmental effects of such discharges are 
minimal. See 61 Fed. Reg. 65,874 (1996), modified at 65 Fed. Reg. 12,818 
(2000). NWP #39 authorizes up to 0.5 acres of fill in isolated waters. 65 
Fed. Reg. 12,818 (2000). Many of the activities authorized by general 
permits require no predischarge notification. 

Even if it were otherwise appropriate for this Court to assess the 
propriety of the Corps’ jurisdictional rule as applied to other hypothetical 
discharges, it is not clear how such analysis could workably be conducted. 
Whether the Corps’ assertion of regulatory jurisdiction in hypothetical 
cases would violate the Constitution surely depends in part on (a) whether 
the landowner is ultimately allowed to carry out the proposed activity, and 
(b) whether the permitting process itself is unduly burdensome. Such 
questions can be answered only by examining the application of the 
regulatory scheme as a whole to the facts of an actual case. Cf. 
Williamson County Regional Planning Comm’n v. Hamilton Bank, 473 
U.S. 172, 186-194 (1985). 

36 As the court of appeals explained, moreover, 

any suggestion that next the Corps will be trying to regulate the 
filling of every puddle that forms after a rainstorm, at least if a bird is 
seen splashing in it, misses the point. A “habitat” is not simply a 
place where a bird might alight for a few minutes, as [petitioner] sug- 
gests, but rather “the place where a plant or animal species naturally 
lives or grows.” Webster’s Third New International Dictionary 1017 
(1993). 

Pet. App. 7a-8a. In the instant case, both the Corps and the FWS empha- 
sized the dependence of numerous bird populations on the waters that 
petitioner proposed to fill. See pp. 8-9, supra. 

37 While Section 404 permits may occasionally be required to undertake 
discharges not conducted as part of a commercial project—e.g., a private 
homeowner’s decision to fill waters in his backyard without the use of 
a commercial contractor—such activities may be regarded as quasi- 
economic in essentially the same way as the homegrown wheat production 
and consumption that was at issue in Wickard. See Lopez, 514 U.S. at 560 

47 

facts before the Court is especially appropriate given the 
absence of any suggestion that this case involves an atypical 
application of the Corps’ regulatory scheme. 

38 

C. The Destruction Of Migratory Bird Habitat Has Sub- 
stantial Effects On Interstate Commerce 

The destruction of migratory bird habitat can be expected 
to have a substantial aggregate effect on interstate com- 
merce. Migratory birds are the object of hunting activities 
that generate billions of dollars of commerce each year. In 
1996, 3.1 million people hunted migratory birds and spent 
$1.3 billion doing so. 

39 Fish and Wildlife Serv., U.S. Dep’t of 
the Interior, & Bureau of the Census, U.S. Dep’t of 

(“Even Wickard * * * involved economic activity in a way that the 
possession of a gun in a school zone does not.”). Such activities are likely 
to affect the value of the real estate and are essentially a mechanism by 
which the homeowner undertakes his own improvements in lieu of em- 
ploying a commercial contractor. Compare Wickard, 317 U.S. at 128 
(homegrown wheat “supplies a need of the man who grew it which would 
otherwise be reflected by purchases in the open market”) (quoted in 
Lopez, 514 U.S. at 560). In any event, the absence of a bright line between 
commercial and non-commercial dredge and fill activities simply reinforces 
the appropriateness of focusing on the facts of this case, rather than on 
hypothetical circumstances not before the Court. 

38 As petitioner observes (Br. 45-46), this Court in Lopez attached no 
constitutional significance to evidence indicating that the defendant him- 
self had possessed a gun with the intent to sell it. In Lopez, however, 
there was no reason to believe that the arguably commercial character of 
the defendant’s own conduct was in any way typical of Gun Free School 
Zones Act violations generally. Moreover, that commercial nexus was 
legally irrelevant to Lopez’s guilt of the offense with which he was 
charged. By contrast, the Corps’ decision whether to grant a Section 404 
permit is based on consideration of a wide range of factors, including 
economic concerns. See 33 C.F.R. Pt. 320. 

39 Among the migratory bird species that were found to use peti- 
tioner’s waters were mallards, wood ducks, and Canada geese, which are 
commonly associated with recreational hunting. Fed. C.A. App. 6-10 (A.R. 
2464-2468). 

48 

Commerce, 1996 National Survey of Fishing, Hunting, and 
Wildlife-Associated Recreation 25 (1997) (1996 National 
Survey); Pet. App. 7a. Ducks and geese, like those that use 
petitioners’ ponds for habitat, are two of the most popular 
game birds, and were hunted by 2.5 million people in 
1996. 1996 National Survey 26; see also Waterfowl Plan 1 
(“Waterfowl are the most prominent and economically 
important group of migratory birds in North America. * * * 
Waterfowl generate a direct expenditure in excess of several 
billions of dollars annually.”). Migratory bird hunters spend 
$720 million per year on hunting equipment, and 11% of bird 
hunters cross state lines to hunt. 1996 National Survey 25, 

60. 
Like bird hunting, bird watching annually generates 
several billion dollars of commerce. In 1996 some 62.9 
million Americans spent $29 billion on wildlife-watching 
activities, including bird-watching. 1996 National Survey 

91. Almost $20 billion is spent each year on equipment for 
wildlife-watching. Ibid. Out of 17.7 million bird-watchers, 

14.3 million people took trips specifically to observe, feed, or 
photograph waterfowl; 9.5 million took trips for other water- 
associated birds, such as herons. Id. at 45, 90. More than 6 
million people crossed state lines in order to engage in 
birdwatching. Id. at 90. 

40 

The court of appeals correctly held that “the destruction 
of migratory bird habitat and the attendant decrease in the 
populations of these birds ‘substantially affects’ interstate 
commerce. The effect may not be observable as each 
isolated pond used by the birds for feeding, nesting, and 

40 The Court in Missouri v. Holland stated that it “s[aw] nothing in the 
Constitution that compels the Government to sit by while a food supply is 
cut off and the protectors of our forests and our crops are destroyed.” 252 
U.S. at 435 (emphasis added). The italicized language presumably refers 
to the fact that the birds eat insects that might otherwise destroy plant 
life. That link provides an additional way in which protection of migratory 
bird habitat ultimately furthers national economic interests. 

49 

breeding is filled, but the aggregate effect is clear, and that 
is all the Commerce Clause requires.” Pet. App. 7a. Pro- 
tection of national economic resources from the ill effects of 
local commercial activity is well within Congress’s authority 
under the Commerce Clause, and the protection of migratory 
birds has long been regarded as a task primarily entrusted 
to national rather than state authorities. Petitioner’s consti- 
tutional challenge to the Corps’ assertion of regulatory juris- 
diction in this case should therefore be rejected. 

CONCLUSION 

The judgment of the court of appeals should be affirmed. 

Respectfully submitted. 

SETH P. WAXMAN 

Solicitor General 

LOIS J. SCHIFFER 

Assistant Attorney General 

LAWRENCE G. WALLACE 

Deputy Solicitor General 

MALCOLM L. STEWART 

Assistant to the Solicitor 

General 

JOSEPH M. FERGUSON 
JOHN A. BRYSON 
JARED A. GOLDSTEIN 

Attorneys 

SEPTEMBER 2000