Order Code RL33263
CRS Report for Congress
Received through the CRS Web
The Wetlands Coverage of the Clean Water Act
is Revisited by the Supreme Court:
Rapanos and Carabell
February 2, 2006
Robert Meltz
Legislative Attorney
American Law Division
Claudia Copeland
Specialist in Resources and Environmental Policy
Resources, Science, and Industry Division
Congressional Research Service ˜ The Library of Congress

The Wetlands Coverage of the Clean Water Act
is Revisited by the Supreme Court:
Rapanos and Carabell
Summary
Twice in the past, the Supreme Court has grappled with issues as to the
geographic scope of the wetlands permitting program in the federal Clean Water Act
(CWA). On October 11, 2005, the Supreme Court agreed to hear two more cases
(consolidated by the Court) addressing such questions — both from the Sixth
Circuit. In Rapanos v. United States, the issue is whether the permitting program
applies to wetlands that are only distantly connected to traditional navigable waters
— i.e., or at least do not actually abut them. In Carabell v. U.S. Army Corps of
Engineers
, the issue is whether the program reaches wetlands that are not
hydrologically connected to any “water of the United States,” the CWA term that
defines the act’s geographic reach. Both cases also raise a constitutional question:
assuming that the disputed CWA coverage exists, did Congress, in enacting the
CWA, exceed its authority under the Commerce Clause of the Constitution?
Implicating hot-button legal issues such as federal-state relations under the
Commerce Clause and private property rights, and affecting the reach of several
CWA provisions outside the permitting program, the Court’s decision is sure to be
of great interest.
The policy question associated with these cases — what should be the outer
geographic limit of CWA jurisdiction and what are the consequences of restricting
the scope of regulatory protection under the act — has challenged regulators,
landowners and developers, and policymakers for more than 30 years. The answer
is important, because as noted it determines the extent of federal CWA regulatory
authority not only for the wetlands permitting program but also for several other
CWA programs; the CWA has one definition of “navigable waters” that applies to
the entire law. Critics of the regulatory program want the federal government to give
up jurisdiction over most non-navigable tributaries and wetlands adjacent thereto,
and allow other federal and state programs to fill whatever gap such changes would
create.
While regulators and the regulated community debate the legal dimensions of
federal jurisdiction under the CWA, scientists contend that there are no discrete,
scientifically supportable boundaries or criteria along the continuum of wetlands to
separate them into meaningful ecological or hydrological compartments. Wetland
scientists believe that all such waters are critical for protecting the integrity of waters,
habitat, and wildlife downstream. Changes in the limits of federal jurisdiction
highlight the role of states in protecting waters not addressed by federal law. From
the states’ perspective, federal programs provide a baseline for consistent, minimum
standards to regulate wetlands and other waters. Most states are either reluctant or
unable to take steps to protect non-jurisdictional waters through legislative or
administrative action.
A Supreme Court decision in Rapanos and Carabell is expected by June 2006.
This report will be updated as developments warrant.

Contents
Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Rapanos v. United States: Distant Hydrological Connection . . . . . . . . . . . . . . . . 4
Carabell v. U.S. Army Corps of Engineers: No Hydrological Connection . . . . . . 5
Legal Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Policy Implications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Filling the Gaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

The Wetlands Coverage of the Clean Water
Act is Revisited by the Supreme Court:
Rapanos and Carabell
On October 11, 2005, the Supreme Court agreed to review two Sixth Circuit
decisions addressing the outer bounds of the geographic coverage of the federal
Clean Water Act (CWA).1 In Rapanos v. United States,2 the issue is whether the
CWA’s wetlands permitting program applies to wetlands that are only distantly
connected to traditional navigable waters — or at a minimum, do not abut them. In
Carabell v. U.S. Army Corps of Engineers,3 the issue is whether that same program
reaches wetlands that are not hydrologically connected to any “water of the United
States,” the CWA phrase defining the geographic reach of the act. Both cases also
raise a constitutional question: if the disputed CWA coverage exists, did Congress
exceed its authority under the Commerce Clause of the Constitution?4
In taking these separate cases (consolidated by the Court for oral argument and
decision), the Court revisits a CWA conundrum with which it and many other courts
have wrestled for three decades: which wetlands are to be regulated under the
federal CWA and which fall solely within the jurisdiction of the states in which they
are located
.
Wetlands, with a variety of physical characteristics, are found throughout the
country. They are known in different regions as swamps, marshes, fens, potholes,
playa lakes, or bogs. Although these places can differ greatly, they all have
distinctive plant and animal assemblages because of the wetness of the soil. Some
wetland areas may be continuously inundated by water, while other areas may not be
flooded at all. In coastal areas, flooding may occur on a daily basis as tides rise and
fall.
1 33 U.S.C. §§ 1251-1387.
2 United States v. Rapanos, 376 F.3d 629 (6th Cir. 2004), cert. granted sub nom. Rapanos
v. United States
, 74 U.S.L.W. 3228 (Oct. 11, 2005) (No. 04-1034).
3 Carabell v. U.S. Army Corps of Engineers, 391 F.3d 704 (6th Cir. 2004), cert. granted
under same name
, 74 U.S.L.W. 3228 (Oct. 11, 2005) (No. 04-1384).
4 The Commerce Clause, U.S. Const. art. I, § 8, cl. 3, gives the Congress authority “To
regulate Commerce ... among the several States ....”

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Background
From the earliest days, Congress grappled with where to set the outer bound of
federal authority over the nation’s waterways, particularly with regard to uses of
waterways that impaired navigation. The phrase Congress often used to define
federal authority was “navigable waters of the United States.”5 The concept proved
an elastic one: in Supreme Court decisions from the early to mid-twentieth century,
“navigability” underwent a substantial expansion “from waters in actual use to those
which used to be navigable to those which by reasonable improvements could be
made navigable to nonnavigable tributaries affecting navigable streams.”6
Notwithstanding the Court’s enlargement of “navigability,” the Congress
considering the legislation that became the CWA of 19727 felt that the term was too
constricted to define the reach of a law whose purpose was not maintaining
navigability, but rather preventing pollution. Accordingly, Congress in the CWA
retained the traditional term “navigable waters,” but defined it to mean “waters of the
United States”8 — seemingly minimizing, if not eliminating, the constraint of
navigability. The conference report said that the new phrase was intended to be
given “the broadest possible constitutional interpretation.”9
Among the provisions in the 1972 clean water legislation was section 404,10
which together with section 301(a) requires persons wishing to discharge dredged or
fill material into “navigable waters,” as newly defined, to obtain a permit from the
U.S. Army Corps of Engineers.11 The Corps’ initial response to section 404 was to
apply it solely to waters traditionally deemed navigable (which included few wetland
areas), despite the broadening “waters of the United States” definition and conference
report language. Under a 1975 court order,12 however, the Corps issued new
regulations that swept up a range of wetlands.13 This broadening ushered in a debate,
continuing today, as to which wetlands Congress meant to reach in the section 404
5 See in particular two precursors of the CWA: Rivers and Harbors Act of 1899 §§ 10 (33
U.S.C. § 403), and 13 (33 U.S.C. § 407). Section 13 covers tributaries of navigable waters
as well.
6 William H. Rodgers, Jr., Handbook on Environmental Law 401 (1977) (footnotes omitted).
7 P.L. 92-500. To be precise, the 1972 enactment was titled the Federal Water Pollution
Control Act Amendments of 1972. It was only after the 1977 amendments thereto that the
act as a whole became known as the Clean Water Act.
8 CWA § 502(7), 33 U.S.C. § 1362(7).
9 Conference report S.Rept. 92-1236 at 144, reprinted in 1972 U.S. Code Cong. & Admin.
News 3776, 3822.
10 33 U.S.C. § 1344.
11 Section 301(a), 33 U.S.C. § 1311(a), prohibits the discharge of any pollutant, except in
compliance with various CWA sections, including section 404.
12 NRDC v. Callaway, 392 F. Supp. 685 (D.D.C. 1975).
13 40 Fed. Reg. 31320 (July 25, 1975), amending 33 C.F.R. part 209.

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permit program. At one time or another, the debate has occupied all three branches
of the federal government.
As the title of this report indicates, Rapanos and Carabell are not the Supreme
Court’s first foray into the section 404 jurisdictional quagmire. In 1985, in Riverside
Bayview Homes, Inc. v. United States
,14 the Court unanimously upheld as reasonable
the Corps’ extension of its section 404 jurisdiction to “adjacent wetlands” — as one
component of its definition of “waters of the United States.”15 Under the Corps
regulations, adjacent wetlands are wetlands adjacent to navigable bodies of water or
interstate waters, or their tributaries.16 The Court reasoned that the water-quality
objectives of the CWA were broad and sensitive to the fact that water moves in
hydrologic cycles. Due to the frequent difficulties in defining where water ends and
land begins, the Court could not say that the Corps’ conclusion that adjacent wetlands
are inseparably bound up with “waters of the United States” was unreasonable,
particularly given the deference owed to the Corps’ and EPA’s ecological expertise.
Also persuasive was the fact that in considering the 1977 amendments to the CWA,
Congress vigorously debated but ultimately rejected amendments that would have
narrowed the Corps’ asserted jurisdiction under section 404.
In 2001, the Court returned to the geographic reach of section 404. The
decision in Solid Waste Agency of Northern Cook County v. U.S. Army Corps of
Engineers
(SWANCC)17 directly involved the “isolated waters” component of the
Corps’ definition of “waters of the United States,”18 rather than the “adjacent
wetlands” component at issue above. “Isolated waters,” in CWA parlance, are waters
that are not traditional navigable waters, are not interstate, are not tributaries of the
foregoing, and are not hydrologically connected to navigable or interstate waters or
their tributaries - — but whose “use, degradation, or destruction [nonetheless] could
affect interstate commerce.”19 Illustrative examples include “intrastate lakes, rivers,
streams (including intermittent streams), mudflats, sandflats, wetlands, sloughs, [or]
prairie potholes”20 with an interstate commerce nexus. The issue before the Court
was whether “waters of the United States” is broad enough to embrace the Corps’
assertion of jurisdiction over such “isolated waters” purely on the ground that they
are or might be used by migratory birds that cross state lines — known as the
Migratory Bird Rule.
In a 5-4 ruling, the majority opinion held that the Migratory Bird Rule was not
authorized by the CWA. The decision’s rationale was much broader, however,
appearing to preclude federal assertion of 404 jurisdiction over isolated waters on any
14 474 U.S. 121 (1985).
15 33 C.F.R. § 328.3(a)(7). An identical EPA definition is at 40 C.F.R. § 230.3(s)(7).
16 See note 15, supra.
17 531 U.S. 159 (2001).
18 33 C.F.R. § 328.3(a)(3). An identical EPA definition is at 40 C.F.R. § 230.3(s)(3).
19 See note 18, supra.
20 See note 18, supra (emphasis added).

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basis — indeed, over wetlands not adjacent to “open water.”21 This disparity
between the Court’s holding and its rationale has occasioned considerable litigation
in the lower courts, the majority of which opts for a narrow reading of SWANCC,
hence a broad reading of remaining Corps jurisdiction under section 404. Such
uncertainties as to the Corps’ isolated waters jurisdiction after SWANCC has focused
attention on the alternative bases in Corps regulations for asserting 404 jurisdiction
— such as the existence of “adjacent wetlands.” Neither the Corps of Engineers nor
EPA, however, has modified its section 404 regulations since SWANCC.
The new spotlight on the concept of adjacent wetlands is the backdrop for the
Supreme Court’s consideration of Rapanos and Carabell, two “adjacent wetlands”
cases.
Rapanos v. United States:
Distant Hydrological Connection
The Rapanos case arose as a civil enforcement action filed by the United States
in 2000, seeking penalties for the filling of Michigan wetlands without a section 404
permit. (In a separate federal criminal action, John Rapanos was convicted in 1995
of illegally discharging fill material into protected wetlands.) As in Riverside
Bayview
, the issue was the Corps’ jurisdiction under the “adjacent wetlands”
component of its regulations defining “waters of the United States.” In particular,
plaintiffs argued that SWANCC did more than throw out the Migratory Bird Rule; it
also barred section 404 regulation of wetlands that do not physically abut a traditional
navigable water.
In ruling that section 404 reached the Rapanos’ wetlands, the Sixth Circuit held
that immediate adjacency of the wetland to a traditional navigable water is not
required. Rather, what is needed is a “significant nexus” — a ubiquitous phrase in
section 404 litigation lifted from SWANCC’s explanation of Riverside Bayview22
between the wetlands and traditional navigable waters. “Significant nexus,” in turn,
can be satisfied by the presence of a “hydrological connection.” Thus, the fact that
the Rapanos’ wetlands had surface water connections to nearby tributaries of
traditional navigable waters was sufficient for section 404 jurisdiction. Nor did it
seem to matter to the court that the hydrological connection to traditional navigable
waters was, for at least one of the Rapanos wetlands, distant — surface waters from
this wetland flow into a man-made drain immediately north of the site, which empties
into a creek, which flows into a navigable river. According to the record, this
wetland is between eleven and twenty miles from the nearest navigable-in-fact water.
In ruling that surface water connection to a tributary of a navigable water was
21 In SWANCC dictum, the Court stated: “In order to rule for the [Corps of Engineers], we
would have to hold that the jurisdiction of the Corps extends to ponds that are not adjacent
to open water. But we conclude that the text of the statute will not allow this.” 531 U.S.
at 168 (emphasis in original).
22 SWANCC, 531 U.S. at 167.

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enough, the circuit aligned itself with the large majority of appellate courts to rule on
this issue since SWANCC.
In its petition for certiorari to the Supreme Court, the Rapanoses ask whether the
CWA’s reach extends to nonnavigable wetlands “that do not even abut a navigable
water.” If a hydrological connection, “no matter how tenuous or remote,” is all that
is required, the Rapanos’ petition also asks whether such CWA jurisdiction would
exceed Congress’ power under the Commerce Clause.
Carabell v. U.S. Army Corps of Engineers:
No Hydrological Connection
Like the Rapanoses, the Carabells owned a wetland tract in Michigan. They
wished to develop it for a condominium project. Unlike the Rapanoses, the Carabells
pursued the required wetlands permitting process — state, then federal. The Carabell
case arose as their challenge to the Corps’ denial of the section 404 permit, and
raised, among other things, the issue of whether the Corps had jurisdiction over the
wetland.
The Sixth Circuit held that “adjacent wetlands” jurisdiction existed under the
Corps regulations, even though the wetland was separated from a tributary of “waters
of the United States” by a four-foot-wide manmade berm that blocked immediate
drainage of surface water from the parcel to the tributary.23 The existence of the
berm meant, critically, that unlike the wetlands in Rapanos, the wetlands here lacked
any hydrological connection to navigable waters at all. Parenthetically, the fact that
the “tributary” was merely a man-made ditch (which emptied into a creek, which
flowed into a navigable lake) did not appear to be an issue in the case, as it was in
Rapanos. Finally, the court endorsed the view of the majority of courts addressing
the question that SWANCC spoke only to the Corps’ “isolated waters” jurisdiction;
it did not narrow the agency’s “adjacent wetlands” authority involved here and
broadly construed in Riverside Bayview.
In its petition for certiorari, the Carabells ask whether section 404 extends to
“wetlands that are hydrologically isolated from any of the ‘waters of the United
States’.” If so, the petition asks the same follow-up question as in Rapanos: Would
such CWA jurisdiction exceed Congress’ power under the Commerce Clause?
23 Corps of Engineers regulations define the word “adjacent” in “adjacent wetlands” to mean
“bordering, contiguous, or neighboring. Wetlands separated from other waters of the
United States by man-made dikes or barriers ... are ‘adjacent wetlands.’” 33 C.F.R. §
328.3(c).

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Legal Analysis
The jurisdictional questions raised by Rapanos and Carabell present the
Supreme Court with a “perfect storm” of hot-button issues. First, there is the
federalism matter: where do CWA section 404 and the Constitution’s Commerce
Clause draw the line between federal and state authority over wetlands? The
Supreme Court has been newly active in the Commerce Clause area since 1995 —
part of a willingness on the part of certain justices, particularly during this period, to
limit federal power under several constitutional provisions.24 The Court’s Commerce
Clause views are of linch-pin importance to several federal environmental laws,
among others, resting as those laws do on Congress’ power under the Clause. What
makes the section 404 program particularly vulnerable to any future judicial
narrowing of the commerce power is the program’s frequent application to wetlands
where the constitutionally required nexus to interstate commerce is not obvious. The
same holds true of applications of the Endangered Species Act to protect species,
subspecies, and vertebrate populations that do not cross state lines.25 Challenges to
the more intrastate applications of both statutes, and likely others, may proliferate
should the Court pare down the commerce power in Rapanos or Carabell.
Second, there are property rights concerns. Some 75% of jurisdictional
wetlands in the lower 48 are on private property, with the result that protests from
property owners denied section 404 permits (or subjected to unacceptable conditions
on same) are often heard — sometimes in the courts through Fifth Amendment
24 Two justices closely associated with the Court’s recent reexaminations of the boundary
between federal and state power under the Constitution, Chief Justice Rehnquist and Justice
O’Connor, have now left the Court. The federal-state views of their replacements, Chief
Justice John Roberts and Justice Samuel Alito respectively, were a recurring theme during
their confirmation hearings. The limited Commerce Clause writings of these new justices
suggest views similar to those of their predecessors. Then-Judge Roberts was one of two
dissenters from the denial of rehearing en banc in Rancho Viejo, LLC v. Norton, 334 F.3d
1158, 1160 (D.C. Cir. 2003), an Endangered Species Act decision rejecting a Commerce
Clause challenge to the act. Perhaps coincidentally, the Supreme Court’s decision to hear
Rapanos and Carabell, following several denials of certiorari in cases raising similar issues,
was made in the first conference of the justices presided over by Chief Justice Roberts.
Then-Judge Alito dissented from the Third Circuit’s decision upholding as within the
Commerce Power a federal law banning the possession and transfer of machine guns.
United States v. Rybar, 103 F.3d 273 (3d Cir. 1996). Previously, several federal circuits had
determined, under various rationales, that the machine gun ban was not a violation of the
Commerce Clause.
25 16 U.S.C. §§ 1531-1544. Though all Commerce Clause challenges to applications of the
Endangered Species Act have failed thus far, several vigorous dissents have been registered.
Both Gibbs v. Babbitt, 214 F.3d 483 (4th Cir. 2000), cert. denied, 531 U.S. 1145 (2001), and
National Ass’n of Homebuilders v. Babbitt, 130 F.3d 1041 (D.C. Cir. 1997), cert. denied,
524 U.S. 937 (1998), were decided on 2-1 votes. In two other Endangered Species Act
cases, circuit court decisions to deny rehearing en banc after rejecting a Commerce Clause
challenge caused more than one judge of the court to object: GDF Realty Investments, Ltd.
v. Norton, 362 F.3d 286 (5th Cir. 2004) (six judges in dissent), cert. denied, 125 S. Ct. 2898
(2005), and Rancho Viejo, LLC v. Norton, 334 F.3d 1158 (D.C. Cir. 2003) (two judges in
dissent), cert. denied, 540 U.S. 1218 (2004).

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takings suits. The public visibility of such grievances is often heightened by property
rights organizations and their allies in Congress. And third, there is the legal tension
stemming from the hybrid land/water nature of wetlands. In American law, the rights
of landowners generally are multifold and relatively unqualified; rights in water, by
contrast, tend to be limited and highly qualified. Wetlands law, standing at the
intersection of these two bodies of law, reflects the tension between them.
Aside from these broad jurisprudential concerns, Rapanos and Carabell have
pervasive significance within the CWA itself. The CWA jurisdictional phrase
“waters of the United States” that the Court likely will construe in those cases
governs not only the section 404 wetlands permitting program, but also multiple
other provisions and requirements of that law (see discussion below under Policy
Implications). In addition, the Oil Pollution Act of 1990 uses “waters of the United
States” to define its scope.26

As to how the Supreme Court decision might come out, one can only say that
the petitioners’ argument in Rapanos seems a harder sell than that in Carabell. The
Rapanos’ ask the Court to deny CWA and constitutional coverage of waters that are,
albeit tenuously, connected to navigable-in-fact waters. In light of the broad
purposes of the CWA and the broad reach of the Commerce Clause, this argument
may prove a tough one.27 The Carabells, however, ask only that waters not connected
at all to navigable waters be ruled off limits.
The two cases are to be argued on February 21, 2006, with a decision likely by
June. Reflecting their importance, numerous amicus briefs have been filed on both
sides, including a few by organizations that claim never to have filed amicus briefs
before. Some current and former Members of Congress also are among the amici.28
Policy Implications

The policy question associated with these cases — what should be the outer
limit of CWA regulatory jurisdiction and what are the consequences of restricting the
geographic scope of regulatory protection under the act — has challenged regulators,
landowners and developers, and policymakers since passage of the act in 1972.
The act prohibits the discharge of dredged or fill material into navigable waters
without a permit, and it also prohibits discharges of pollutants from any point source
to navigable waters without a permit. Disputes have centered on whether wetlands
26 33 U.S.C. § 2701(21).
27 CWA and constitutional coverage of remotely connected waters were upheld in United
States v. Deaton, 332 F.3d 698 (4th Cir. 2003), cert. denied, 541 U.S. 972 (2004). Joining
the court’s unanimous opinion were two generally conservative judges, Judge Wilkinson and
Judge Luttig.
28 Rep. John Duncan (R-Tenn.) filed on the side of petitioners Rapanos and Carabell. Reps.
John Dingell (D-Mich.), John Conyers (D-Mich.), and Charles Rangel (D-N.Y.), plus
several former Members of Congress, filed on the side of respondent United States.

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and other waters are navigable waters. The answer to this question is important,
because it determines the extent of federal CWA regulatory authority not only for the
section 404 program, but also for purposes of implementing other CWA programs.
Critics of the section 404 regulatory program, such as land developers and agriculture
interests, argue that the Corps’ wetlands program has gradually and illegally
expanded its asserted jurisdiction since 1972. They want the Corps and EPA to give
up jurisdiction over most non-navigable tributaries and allow other federal and state
programs to fill whatever gap is created.
Waters that are jurisdictional are subject to the multiple regulatory requirements
of the CWA: standards, discharge limitations, permits, and enforcement. Non-
jurisdictional waters, in contrast, do not have the federal legal protection of those
requirements. The act has one definition of “navigable waters” that applies to the
entire law. The definition applies to: federal prohibition on discharges of pollutants
(section 301), requirements to obtain a permit prior to discharge (sections 402 and
404), water quality standards and measures to attain them (section 303), oil spill
liability and oil spill prevention and control measures (section 311), certification that
federally permitted activities comply with state water quality standards (section 401),
and enforcement (section 309). As noted above, it impacts the Oil Pollution Act and
other environmental laws as well. For example, the reach of the Endangered Species
Act (ESA) is affected, because that act’s requirement for consultation by federal
agencies over impacts on threatened or endangered species is triggered through the
issuance of federal permits.29 Thus, by removing the need for a CWA permit, a non-
jurisdictional determination would eliminate ESA consultation, as well.
SWANCC challenged and found invalid the assertion of CWA jurisdiction over
isolated, non-navigable intrastate waters solely on the basis of their use (or potential
use) as habitat by migratory birds. Most of the post-SWANCC cases have, instead,
addressed tributaries and adjacent wetlands, asking which of these have the
“significant nexus” to navigable waters that the Supreme Court has said is necessary
to establish federal jurisdiction.
Wetlands are an important part of the total aquatic ecosystem, with many
recognized functions and values, including water storage (mitigating the effects of
floods and droughts), water purification and filtering, recreation, habitat for plants
and animals, food production, and open space and aesthetic values. Functional
values, both ecological and economic, at each wetland depend on its location, size,
and relationship to adjacent land and water areas. To the layman, many of these
values are more obvious for wetlands adjacent to large rivers and streams than they
are for wetlands and small streams that are isolated in the landscape from other
waters. Many of the functions and values of wetlands have been recognized only
recently. Historically, many federal programs encouraged wetlands to be drained or
altered because they were seen as having little value. Even today, while more federal
laws either encourage wetland protection or regulate their modification, pressure
exists to modify, drain, or develop wetlands for uses that some see as more
economically beneficial.
29 16 U.S.C. § 1536.

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While regulators and the regulated community debate the legal dimensions of
federal jurisdiction, scientists contend that there are no discrete, scientifically
supportable boundaries or criteria along the continuum of wetlands to separate them
into meaningful ecological or hydrological compartments. Numerous scientific
studies define and describe the importance of the functions and values of wetlands,
in support of their significant nexus to navigable waters.30 In all but some very
narrow instances, scientists say, terms such as “isolated waters” and “adjacent
wetlands” are artificial legal or regulatory constructs, not valid scientific
classifications. From this perspective, even waters that lack a direct surface
connection to navigable waters or that only flow intermittently are connected to the
larger aquatic ecosystem via subsurface or overflow hydrologic connections.
Wetland scientists believe that all such waters are critical for protecting the integrity
of waters, habitat, and wildlife downstream.
In SWANCC, the Supreme Court did not draw a bright line for regulatory
purposes of determining the limits of federal jurisdiction (and wetland scientists do
not believe that a bright line is possible, in any case). While the ruling reduced
federal jurisdiction over some previously regulated wetlands, even nearly five years
later, it remains difficult to determine the precise effect of that decision. Many
affected interests (states and the regulated community) contend that guidance from
the Corps and EPA has not adequately defined the scope of regulated areas and
wetlands affected by SWANCC and subsequent court rulings.31 In addition, the
Government Accountability Office found that uncertainties are amplified by
variability in jurisdictional determinations made by the 38 Corps District offices that
administer the CWA section 404 permit program.32 The Rapanoses and the Carabells
hope that the Supreme Court will clarify the jurisdiction issue and that the Court will
further narrow the program’s geographic reach.
Estimates of the types of wetlands and amounts of affected acreage depend on
interpretation of SWANCC and subsequent court rulings and on assumptions about
defining key terms such as “adjacent,” “tributary,” and “significant nexus.” Because
in its regulations before SWANCC the Corps had broadly defined “waters of the
United States,” including those encompassed by the Migratory Bird Rule, nearly all
U.S. wetlands and waters were subject to CWA jurisdiction, since practically all are
used to a greater or lesser extent by migratory birds.33 Depending on how key terms
are now defined, reduced federal jurisdiction could affect very small or very large
30 Leibowitz, Scott G. “Isolated Wetlands and Their Functions: An Ecological Perspective.”
Wetlands. Vol. 23, no. 3, September 2003. pp. 517-531.
31 See, for example: U.S. Congress. House of Representatives. Committee on
Transportation and Infrastructure. Subcommittee on Water Resources and Environment.
“Inconsistent Regulation of Wetlands and Other Waters.” Hearing, 108th Congress, 2d
Session, March 30, 2004. (H.Hrg. 108-58) 200 p.
32 U.S. Government Accountability Office. “Corps of Engineers Needs to Evaluate Its
District Office Practices in Determining Jurisdiction.” GAO-04-297. February 2004.
33 Kusler, Jon. The Association of State Wetland Managers. “‘Waters of the U.S.’ After
SWANCC.” August 12, 2005 (draft), p. 6.

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categories of waters and wetlands. The possible changes in jurisdiction could range
from 20% to 80% of the Nation’s total estimated 100 million acres of wetlands.34
! Under a narrow interpretation of SWANCC allowing the Corps to
regulate traditionally navigable waters, tributaries, adjacent
wetlands, and other wetlands with a significant nexus (even if they
are not tributary or adjacent), 80-90% of wetlands would be
regulated under federal law. Documentation of such nexus would
likely need to be made on a case-by-case basis.
! If the Corps regulates traditionally navigable waters and their
adjacent wetlands, plus tributaries and wetlands adjacent to all
tributaries, 40-60% or more of all wetlands are likely to be regulated.
Much depends on how the Corps, EPA, and the courts define
“tributary” and “adjacent” — key terms at issue in the Rapanos and
Carabell cases. For example, if “tributary” were narrowly construed
to include only perennial streams, some prairie potholes, vernal
pools, forested wetlands, wet meadows, tundra, and bogs would be
unregulated.
! Under a broad reading of SWANCC, limiting the Corps to only
regulating traditionally navigable waters and adjacent wetlands,
perhaps 20% of the Nation’s wetlands would be subject to federal
regulation. Under this scenario, CWA-regulated wetlands would
primarily include fringe wetlands on large rivers, streams, and lakes,
and coastal and estuarine fringing wetlands.
Filling the Gaps
Whatever gaps in wetland regulation result from reduced federal jurisdiction
arguably could be filled, at least in part, by other federal or state and local programs
and actions. For example, some assert that wetland restoration and creation
programs, such as the Wetlands Reserve Program and the Coastal Wetlands
Restoration Program, or private conservation efforts can provide protection, even if
the wetland is no longer jurisdictional.35 However, others respond that such
programs are likely to be incomplete in filling gaps, since they apply primarily to
rural areas and do not apply to the one-third of the Nation’s lands in federal
ownership. Moreover, they were never intended to be a seamless group that would
fill all possible gaps.
SWANCC and subsequent legal decisions also highlight the role of states in
protecting waters not addressed by federal law. From the states’ perspective, the
federal section 404 program provides the basis for a consistent national approach to
wetlands protection. But if a larger portion of wetlands are no longer jurisdictional,
they say, it can be argued that the section 404 program no longer provides a baseline
34 Kusler, Jon. The Association of State Wetland Managers. “The SWANCC Decision:
State Regulation of Wetlands to Fill the Gap.” March 2004. pp. 6-8. Hereafter, Kusler.
35 U.S. Environmental Protection Agency. “Advance Notice of Proposed Rulemaking on the
Clean Water Act Regulatory Definition of ‘Waters of the United States.’” 68 Federal
Register 1994-95. January 15, 2003.

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for consistent, minimum standards to regulate wetlands. SWANCC and other court
rulings do not prevent states from protecting non-jurisdictional waters through
legislative or administrative action, but few states have done so. Prior to SWANCC,
15 states had programs that regulate isolated freshwater wetlands to some degree, but
state officials acknowledge that these programs vary substantially from some that are
comprehensive in scope to others that are limited by wetland size or have exemptions
for agriculture and other activities.36 Since 2001, a few states have passed new
legislation or updated water quality regulations; the issue remains under
consideration in several states, where competing proposals that are viewed by some
as strengthening and by others as weakening wetland protection are being debated.37
Although some states have authorities to regulate waters of their state, their
ability to regulate effectively may be compromised, because state rules often are tied
to federal definitions. The gap produced by reduced federal jurisdiction is most
evident in the 32 states that have no independent wetlands programs and that
typically have relied on CWA section 401 water quality certification procedures to
protect wetlands. Pursuant to section 401, applicants for a federal permit must obtain
a state certification that the project will comply with state water quality standards.
Consequently, by conditioning certification, states have the ability to affect the
federal permit and to exercise some regulatory control over wetlands without the
expense of establishing independent state programs. However, as described
previously, diminished CWA jurisdiction which affects the section 404 program also
limits the reach of other CWA programs, including section 401.
Analysts familiar with the political and fiscal environments of states believe that
most states are either reluctant or unable “to step boldly into the breach in federal
wetlands protection....The Corps and the U.S. Environmental Protection Agency, not
to mention Congress, have little cause to rely on the notion that states will effectively
backstop federal protection for isolated wetlands.”38 Many states are barred from
enacting laws or rules more stringent than federal rules, or are reluctant to take
action, due to budgetary and resource concerns, as well as apprehension that
regulation will be judged to involve “taking” of private property and require
compensation.
In Congress, legislation has been introduced that would address the CWA
jurisdictional issues discussed here. One proposal, H.R. 1356, the Clean Water
Authority Restoration Act of 2005, would provide a broad statutory definition of
“waters of the United States;” clarify that the CWA is intended to protect U.S. waters
from pollution, not just maintain their navigability; and include a set of findings to
assert constitutional authority over waters and wetlands. Other legislation to restrict
regulatory jurisdiction also has been introduced in the 109th Congress (H.R. 2658, the
Federal Wetlands Jurisdiction Act of 2005). It would narrow the statutory definition
36 Kusler, p. 15.
37 Goldman-Carter, Jan. “Isolated Wetland Legislation: Running the Rapids at the State
Capitol.” National Wetlands Newsletter. May-June 2005. pp. 27-29.
38 Odell, Turner. “On Soggy Ground — State Protection for Isolated Wetlands.” National
Wetlands Newsletter.
September-October 2003. p. 10.

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of “navigable waters” and define certain isolated wetlands and other areas as not
being subject to federal regulatory jurisdiction. Neither bill has received
congressional action.