PRELIMINARY PRINT

             Volume 598 U. S. Part 2
                             Pages 651–728




       OFFICIAL REPORTS
                                    OF


   THE SUPREME COURT
                                May 25, 2023


Page Proof Pending Publication


                   REBECCA A. WOMELDORF
                           reporter of decisions




    NOTICE: This preliminary print is subject to formal revision before
  the bound volume is published. Users are requested to notify the Reporter
  of Decisions, Supreme Court of the United States, Washington, D.C. 20543,
  [email protected], of any typographical or other formal errors.
                          OCTOBER TERM, 2022                                651

                                   Syllabus


SACKETT et ux. v. ENVIRONMENTAL PROTECTION
                 AGENCY et al.
certiorari to the united states court of appeals for
                  the ninth circuit
      No. 21–454. Argued October 3, 2022—Decided May 25, 2023
Petitioners Michael and Chantell Sackett purchased property near Priest
  Lake, Idaho, and began backflling the lot with dirt to prepare for build-
  ing a home. The Environmental Protection Agency informed the Sack-
  etts that their property contained wetlands and that their backflling
  violated the Clean Water Act, which prohibits discharging pollutants
  into “the waters of the United States.” 

(7). The EPA
  ordered the Sacketts to restore the site, threatening penalties of over
  $40,000 per day. The EPA classifed the wetlands on the Sacketts' lot
  as “waters of the United States” because they were near a ditch that
  fed into a creek, which fed into Priest Lake, a navigable, intrastate lake.
  The Sacketts sued, alleging that their property was not “waters of the
  United States.” The District Court entered summary judgment for the
Page Proof Pending Publication
  EPA. The Ninth Circuit affrmed, holding that the CWA covers wet-
  lands with an ecologically signifcant nexus to traditional navigable wa-
  ters and that the Sacketts' wetlands satisfy that standard.
Held: The CWA's use of “waters” in § 1362(7) refers only to “ `geographi-
 c[al] features' that are described in ordinary parlance as `streams,
 oceans, rivers, and lakes' ” and to adjacent wetlands that are “indistin-
 guishable” from those bodies of water due to a continuous surface con-
 nection. Rapanos v. United States, 

 (plural-
 ity opinion). To assert jurisdiction over an adjacent wetland under the
 CWA, a party must establish “frst, that the adjacent [body of water
 constitutes] . . . `water[s] of the United States,' (i. e., a relatively perma-
 nent body of water connected to traditional interstate navigable wa-
 ters); and second, that the wetland has a continuous surface connection
 with that water, making it diffcult to determine where the `water' ends
 and the `wetland' begins.” 

. Pp. 663–684.
    (a) The uncertain meaning of “the waters of the United States”
 has been a persistent problem, sparking decades of agency action and
 litigation. Resolving the CWA's applicability to wetlands requires a
 review of the history surrounding the interpretation of that phrase.
 Pp. 663–671.
       (1) During the period relevant to this case, the two federal agencies
 charged with enforcement of the CWA—the EPA and the Army Corps
652                        SACKETT v. EPA

                                 Syllabus

 of Engineers—similarly defned “the waters of the United States”
 broadly to encompass “[a]ll . . . waters” that “could affect interstate or
 foreign commerce.” 

(s)(3). The agencies likewise gave
 an expansive interpretation of wetlands adjacent to those waters, de-
 fining “adjacent” to mean “bordering, contiguous, or neighboring.”
 § 230.3(b). In United States v. Riverside Bayview Homes, Inc., 

, the Court confronted the Corps' assertion of authority under
 the CWA over wetlands that “actually abut[ted] on a navigable water-
 way.” 

. Although concerned that the wetlands fell outside
 “traditional notions of `waters,' ” the Court deferred to the Corps, rea-
 soning that “the transition from water to solid ground is not necessarily
 or even typically an abrupt one.” 

 at 132–133. Following River-
 side Bayview, the agencies issued the “migratory bird rule,” extending
 CWA jurisdiction to any waters or wetlands that “are or would be used
 as [a] habitat” by migratory birds or endangered species. 

. The Court rejected the rule after the Corps sought to apply it
 to several isolated ponds located wholly within the State of Illinois, hold-
 ing that the CWA does not “exten[d] to ponds that are not adjacent to
 open water.” Solid Waste Agency of Northern Cook Cty. v. Army
 Corps of Engineers, 

 (SWANCC) (emphasis deleted).
 The agencies responded by instructing their feld agents to determine
Page Proof Pending Publication
 the scope of the CWA's jurisdiction on a case-by-case basis. Within a
 few years, the agencies had “interpreted their jurisdiction over `the wa-
 ters of the United States' to cover 270-to-300 million acres” of wetlands
 and “virtually any parcel of land containing a channel or conduit . . .
 through which rainwater or drainage may occasionally or intermittently
 fow.” Rapanos, 

 (plurality opinion).
    Against that backdrop, the Court in Rapanos vacated a lower court
 decision that had held that the CWA covered wetlands near ditches and
 drains that emptied into navigable waters several miles away. As to
 the rationale for vacating, however, no position in Rapanos commanded
 a majority of the Court. Four Justices concluded that the CWA's cover-
 age was limited to certain relatively permanent bodies of water con-
 nected to traditional interstate navigable waters and to wetlands that
 are “as a practical matter indistinguishable” from those waters. 

 (emphasis deleted). Justice Kennedy, concurring only in the judg-
 ment, wrote that CWA jurisdiction over adjacent wetlands requires a
 “signifcant nexus” between the wetland and its adjacent navigable wa-
 ters, which exists when “the wetlands, either alone or in combination
 with similarly situated lands in the region, signifcantly affect the chemi-
 cal, physical, and biological integrity” of those waters. 

 at 779–780.
 Following Rapanos, feld agents brought nearly all waters and wetlands
 under the risk of CWA jurisdiction by engaging in fact-intensive
                      Cite as: 

 (2023)                     653

                                Syllabus

 “signifcant-nexus” determinations that turned on a lengthy list of hy-
 drological and ecological factors.
    Under the agencies' current rule, traditional navigable waters, inter-
 state waters, and the territorial seas, as well as their tributaries and
 adjacent wetlands, are waters of the United States. See 

. So too are any “[i]ntrastate lakes and ponds, streams, or wet-
 lands” that either have a continuous surface connection to categorically
 included waters or have a signifcant nexus to interstate or traditional
 navigable waters. 

. Finding a signifcant nexus con-
 tinues to require consideration of a list of open-ended factors. 

 Finally, the current rule returns to the agencies' longstanding defnition
 of “adjacent.” 

 Pp. 663–669.
      (2) Landowners who even negligently discharge pollutants into
 navigable waters without a permit potentially face severe criminal and
 civil penalties under the Act. As things currently stand, the agencies
 maintain that the signifcant-nexus test is suffcient to establish jurisdic-
 tion over “adjacent” wetlands. By the EPA's own admission, nearly all
 waters and wetlands are potentially susceptible to regulation under this
 test, putting a staggering array of landowners at risk of criminal prose-
 cution for such mundane activities as moving dirt. Pp. 669–671.
    (b) Next, the Court considers the extent of the CWA's geographical
Page Proof Pending Publication
 reach. Pp. 671–679.
      (1) To make sense of Congress's choice to defne “navigable waters”
 as “the waters of the United States,” the Court concludes that the
 CWA's use of “waters” encompasses “only those relatively permanent,
 standing or continuously fowing bodies of water `forming geographic[al]
 features' that are described in ordinary parlance as `streams, oceans,
 rivers, and lakes.' ” Rapanos, 

 (plurality opinion).
 This reading follows from the CWA's deliberate use of the plural “wa-
 ters,” which refers to those bodies of water listed above, and also helps
 to align the meaning of “the waters of the United States” with the de-
 fned term “navigable waters.” More broadly, this reading accords with
 how Congress has employed the term “waters” elsewhere in the CWA—
 see, e. g., 

(i)(2)(D), 1268(a)(3)(I)—and in other laws—
 see, e. g., 

, 4701(a)(7). This Court has understood
 CWA's use of “waters” in the same way. See, e. g., Riverside Bayview,
 

; SWANCC, 531 U. S., at 168–169, 172.
    The EPA's insistence that “water” is “naturally read to encompass
 wetlands” because the “presence of water is `universally regarded as the
 most basic feature of wetlands' ” proves too much. Brief for Respond-
 ents 19. It is also tough to square with SWANCC's exclusion of isolated
 ponds or Riverside Bayview's extensive focus on the adjacency of wet-
 lands to covered waters. Finally, it is diffcult to see how the States'
654                         SACKETT v. EPA

                                  Syllabus

 “responsibilities and rights” in regulating water resources would re-
 main primary” if the EPA had such broad jurisdiction. § 1251(b).
 Pp. 671–674.
      (2) Statutory context shows that some wetlands nevertheless qual-
 ify as “waters of the United States.” Specifcally, § 1344(g)(1), which
 authorizes States to conduct certain permitting programs, specifes that
 discharges may be permitted into any waters of the United States,
 except for traditional navigable waters, “including wetlands adjacent
 thereto,” suggesting that at least some wetlands must qualify as “waters
 of the United States.” But § 1344(g)(1) cannot defne what wetlands
 the CWA regulates because it is not the operative provision that defnes
 the Act's reach. Instead, the reference to adjacent wetlands in
 § 1344(g)(1) must be harmonized with “the waters of the United States,”
 which is the operative term that defnes the CWA's reach. Because the
 “adjacent” wetlands in § 1344(g)(1) are “includ[ed]” within “waters of
 the United States,” these wetlands must qualify as “waters of the
 United States” in their own right, i. e., be indistinguishably part of a
 body of water that itself constitutes “waters” under the CWA. To hold
 otherwise would require implausibly concluding that Congress tucked
 an important expansion to the reach of the CWA into convoluted lan-
 guage in a relatively obscure provision concerning state permitting pro-
Page Proof Pending Publication
 grams. Understanding the CWA to apply to wetlands that are distin-
 guishable from otherwise covered “waters of the United States” would
 substantially broaden § 1362(7) to defne “navigable waters” as “waters
 of the United States and adjacent wetlands.” But § 1344(g)(1)'s use of
 the term “including” makes clear that it does not purport to do any such
 thing. It merely refects Congress's assumption that certain “adjacent”
 wetlands are part of the “waters of the United States.”
    To determine when a wetland is part of adjacent “waters of the United
 States,” the Court agrees with the Rapanos plurality that the use of
 “waters” in § 1362(7) may be fairly read to include only wetlands that
 are “indistinguishable from waters of the United States.” This occurs
 only when wetlands have “a continuous surface connection to bodies that
 are `waters of the United States' in their own right, so that there is no
 clear demarcation between `waters' and wetlands.” 

.
    In sum, the CWA extends to only wetlands that are “as a practical
 matter indistinguishable from waters of the United States.” This re-
 quires the party asserting jurisdiction to establish “frst, that the adja-
 cent [body of water constitutes] . . . `water[s] of the United States' (i. e.,
 a relatively permanent body of water connected to traditional interstate
 navigable waters); and second, that the wetland has a continuous surface
 connection with that water, making it diffcult to determine where the
 `water' ends and the `wetland' begins.” 

. Pp. 674–679.
                       Cite as: 

 (2023)                     655

                                 Syllabus

     (c) The EPA asks the Court to defer to its most recent rule providing
  that “adjacent wetlands are covered by the [CWA] if they `possess a
  signifcant nexus to' traditional navigable waters” and that wetlands are
  “adjacent” when they are “neighboring” to covered waters. Brief for
  Respondents 32, 20. For multiple reasons, the EPA's position lacks
  merit. Pp. 679–683.
        (1) The EPA's interpretation is inconsistent with the CWA's text
  and structure and clashes with “background principles of construction”
  that apply to the interpretation of the relevant provisions. Bond v.
  United States, 

. First, “exceedingly clear language”
  is required if Congress wishes to alter the federal/state balance or the
  Government's power over private property. United States Forest Serv-
  ice v. Cowpasture River Preservation Assn., 590 U. S. –––, –––. The
  Court has thus required a clear statement from Congress when deter-
  mining the scope of “the waters of the United States.” Second, the
  EPA's interpretation gives rise to serious vagueness concerns in light
  of the CWA's criminal penalties, thus implicating the due process re-
  quirement that penal statutes be defned “ `with suffcient defniteness
  that ordinary people can understand what conduct is prohibited.' ” Mc-
  Donnell v. United States, 

, 576. Where penal statutes

Page Proof Pending Publication
  could sweep broadly enough to render criminal a host of what might
  otherwise be considered ordinary activities, the Court has been wary
  about going beyond what “Congress certainly intended the statute to
  cover.” Skilling v. United States, 

. Under these two
  principles, the judicial task when interpreting “the waters of the United
  States” is to ascertain whether clear congressional authorization exists
  for the EPA's claimed power. Pp. 679–681.
        (2) The EPA claims that Congress ratifed the EPA's regulatory
  defnition of “adjacent” when it amended the CWA to include the refer-
  ence to “adjacent” wetlands in § 1344(g)(1). This argument fails for at
  least three reasons. First, the text of §§ 1362(7) and 1344(g) shows that
  “adjacent” cannot include wetlands that are merely nearby covered wa-
  ters. Second, EPA's argument cannot be reconciled with this Court's
  repeated recognition that § 1344(g)(1) “ `does not conclusively determine
  the construction to be placed on . . . the relevant defnition of “navigable
  waters.” ' ” SWANCC, 

. Third, the EPA falls short of
  establishing the sort of “overwhelming evidence of acquiescence” neces-
  sary to support its argument in the face of Congress's failure to amend
  § 1362(7). Id., at 170, n. 5. Finally, the EPA's various policy arguments
  about the ecological consequences of a narrower defnition of “adjacent”
  are rejected. Pp. 681–683.

, reversed and remanded.
656                        SACKETT v. EPA

                                Syllabus

   Alito, J., delivered the opinion of the Court, in which Roberts, C. J.,
and Thomas, Gorsuch, and Barrett, JJ., joined. Thomas, J., fled a
concurring opinion, in which Gorsuch, J., joined, post, p. 684. Kagan, J.,
fled an opinion concurring in the judgment, in which Sotomayor and
Jackson, JJ., joined, post, p. 710. Kavanaugh, J., fled an opinion concur-
ring in the judgment, in which Sotomayor, Kagan, and Jackson, JJ.,
joined, post, p. 715.

  Damien M. Schiff argued the cause for petitioners. With
him on the briefs was Anthony L. François.
  Acting Solicitor General Fletcher argued the cause for
respondents. With him on the brief were Assistant Attor-
ney General Kim, Deputy Solicitor General Stewart, Mat-
thew Guarnieri, Jennifer Scheller Neumann, Brian C. Toth,
Susannah Landes Weaver, Steven Neugeboren, Karyn I. O.
Wendelowski, Carrie Ricci, and Zaheer Tajani.*

   *Briefs of amici curiae urging reversal were fled for the State of
Alaska by Treg R. Taylor, Attorney General of Alaska, and David A. Wil-
Page Proof Pending Publication
kinson and Julie Pack, Assistant Attorneys General; for the State of West
Virginia et al. by Patrick Morrisey, Attorney General of West Virginia,
Lindsay S. See, Solicitor General, and Michael R. Williams, Senior Dep-
uty Solicitor General, and by the Attorneys General for their respective
States as follows: Steve Marshall of Alabama, Mark Brnovich of Arizona,
Leslie Rutledge of Arkansas, Ashley Moody of Florida, Christopher M.
Carr of Georgia, Lawrence Wasden of Idaho, Theodore E. Rokita of Indi-
ana, Derek Schmidt of Kansas, Daniel Cameron of Kentucky, Jeff Landry
of Louisiana, Lynn Fitch of Mississippi, Eric S. Schmitt of Missouri, Aus-
tin Knudsen of Montana, Douglas J. Peterson of Nebraska, Drew Wrigley
of North Dakota, John Formella of New Hampshire, Dave Yost of Ohio,
John O'Connor of Oklahoma, Alan Wilson of South Carolina, Jason
Ravnsborg of South Dakota, Herbert Slatery of Tennessee, Ken Paxton
of Texas, Sean D. Reyes of Utah, Jason Miyares of Virginia, and Bridget
Hill of Wyoming; for the American Exploration and Mining Association
et al. by Christopher D. Thomas and Andrea J. Driggs; for the American
Petroleum Institute et al. by Catherine E. Stetson, Sean Marotta, and
Meredith B. Cody; for the Americans for Prosperity Foundation by Mi-
chael Pepson and Cynthia Fleming Crawford; for the Associated Indus-
tries of Florida et al. by Terry P. Cole; for the Association of American
Railroads by Fred R. Wagner and Jay C. Johnson; for the Cato Institute
et al. by Jay R. Schweikert, Karen Harned, Cory L. Andrews, and John
                       Cite as: 

 (2023)                   657

                          Opinion of the Court

  Justice Alito delivered the opinion of the Court.
  This case concerns a nagging question about the outer
reaches of the Clean Water Act (CWA), the principal federal

M. Masslon II; for the Chamber of Commerce of the United States of
America by Elbert Lin, Kerry L. McGrath, Erica N. Peterson, and An-
drew R. Varcoe; for Congressional Western Caucus Members by Tyler R.
Green; for Duarte Nursery, Inc., by Timothy Kassouni; for Farm Bureau
of Arkansas et al. by Michael B. Kimberly, Kari E. Fisher, Chad Endsley,
Leah Curtis, Amy Milam, and Christina L. Gruenhagen; for Forestry
Organizations by David Y. Chung, Elizabeth B. Dawson, and William R.
Murray; for Fourteen National Agricultural Organizations by Timothy S.
Bishop, Brett E. Legner, Ellen Steen, Travis Cushman, and Michael C.
Formica; for Freeport-McMoRan Inc. by Jeremy C. Marwell and James
T. Dawson; for the Liberty Justice Center by Daniel R. Suhr; for the
National Stone, Sand and Gravel Association et al. by Lawrence R. Liebes-
man and Nick Goldstein; for the Savannah Economic Development Au-
thority et al. by Misha Tseytlin, Anna Wildeman, and Byron Kirkpat-
rick; for the Southeastern Legal Foundation by Jennifer A. Simon and
Kimberly S. Hermann; and for Sen. Shelley Moore Capito et al. by
Page Proof Pending Publication
Thomas M. Johnson, Jr.
   Briefs of amici curiae urging affrmance were fled for the State of
Colorado by Philip J. Weiser, Attorney General of Colorado, Eric R.
Olson, Solicitor General, Carrie Noteboom, First Assistant Attorney Gen-
eral, and Annette M. Quill and Jennifer Hunt, Senior Assistant Attorneys
General; for the State of New York et al. by Letitia James, Attorney
General of New York, Barbara D. Underwood, Solicitor General, Judith
N. Vale, Deputy Solicitor General, and Mark S. Grube, Assistant Solicitor
General, by Matthew J. Platkin, Acting Attorney General of New Jersey,
and by the Attorneys General for their respective jurisdictions as follows:
Rob Bonta of California, William Tong of Connecticut, Kathleen Jennings
of Delaware, Karl A. Racine of the District of Columbia, Holly T. Shikada
of Hawaii, Kwame Raoul of Illinois, Aaron M. Frey of Maine, Brian E.
Frosh of Maryland, Maura Healey of Massachusetts, Keith Ellison of Min-
nesota, Hector Balderas of New Mexico, Joshua H. Stein of North Caro-
lina, Ellen F. Rosenblum of Oregon, Thomas J. Donovan, Jr., of Vermont,
Robert W. Ferguson of Washington, and Joshua L. Kaul of Wisconsin; for
the American Sustainable Business Network et al. by Benjamin D. Bat-
tles, Max E. Rodriguez, and Alison Borochoff-Porte; for the Constitutional
Accountability Center by Elizabeth B. Wydra and Brianne J. Gorod; for
Environmental and Community Organizations by Nicholas S. Torrey,
Catherine M. Rahm, and Ian Fein; for Former EPA Administrators by
658                         SACKETT v. EPA

                           Opinion of the Court

law regulating water pollution in the United States.1 By
all accounts, the Act has been a great success. Before its
enactment in 1972, many of the Nation's rivers, lakes, and
streams were severely polluted, and existing federal legisla-
tion had proved to be inadequate. Today, many formerly
fetid bodies of water are safe for the use and enjoyment of
the people of this country.
   There is, however, an unfortunate footnote to this success
story: the outer boundaries of the Act's geographical reach
have been uncertain from the start. The Act applies to “the
waters of the United States,” but what does that phrase
mean? Does the term encompass any backyard that is
soggy enough for some minimum period of time? Does it
reach “mudfats, sandfats, wetlands, sloughs, prairie pot-

Beth S. Brinkmann, Gary S. Guzy, and Eric Chung; for the Menominee
Indian Tribe of Wisconsin et al. by Janette K. Brimmer and Jill E. Grant;
for Outdoor Recreation and Conservation Organizations by Jennifer S.
Page Proof Pending Publication
Windom; for Public Citizen by Scott L. Nelson and Allison M. Zieve; for
the Waterkeeper Alliance et al. by Anna-Rose Mathieson, Kelly Hunter
Foster, and Eric J. Buescher; for Water Resource Management Organiza-
tions by Caitlin J. Halligan; and for 167 U. S. Members of Congress by
Sara A. Colangelo.
   Briefs of amici curiae were fled for the Atlantic Legal Foundation et al.
by Lawrence S. Ebner and Nancie G. Marzulla; for the Claremont Insti-
tute's Center for Constitutional Jurisprudence by John C. Eastman and
Anthony T. Caso; for the Idaho Conservation League by Caleb Jaffe; for
the National Association of Clean Water Agencies by Alexandra Dapolito
Dunn, Thomas C. Jackson, and Stephanie F. Cagniart; for the National
Association of Counties et al. by Roderick E. Walston, J. G. Andre Mo-
nette, and Lisa Soronen; for the National Association of Home Builders of
the United States by Thomas J. Ward and Jeffrey B. Augello; for the
National Cattlemen's Beef Association et al. by Scott Yager; for the Prop-
erty and Environment Research Center by Jonathan Wood; for Scientifc
Societies by Royal C. Gardner, Stephanie Tai, Henry Weisburg, Kathleen
E. Gardner, and Erin Okuno; for the Western Urban Water Coalition by
Meredith Weinberg; and for the Wyoming Stock Growers Association et al.
by Karen Budd-Falen.
   1
     

, as amended, 

 et seq.
                     Cite as: 

 (2023)                659

                         Opinion of the Court

holes, wet meadows, [or] playa lakes”? 2 How about ditches,
swimming pools, and puddles?
   For more than a half century, the agencies responsible for
enforcing the Act have wrestled with the problem and
adopted varying interpretations. On three prior occasions,
this Court has tried to clarify the meaning of “the waters of
the United States.” But the problem persists. When we
last addressed the question 17 years ago, we were unable to
agree on an opinion of the Court.3 Today, we return to the
problem and attempt to identify with greater clarity what
the Act means by “the waters of the United States.”

                                  I
                                  A
  For most of this Nation's history, the regulation of water
pollution was left almost entirely to the States and their sub-
divisions. The common law permitted aggrieved parties to
Page Proof Pending Publication
bring nuisance suits against polluters. But as industrial
production and population growth increased the quantity and
toxicity of pollution, States gradually shifted to enforcement
by regulatory agencies.4 Conversely, federal regulation was
largely limited to ensuring that “traditional navigable wa-
ters”—that is, interstate waters that were either navigable
in fact and used in commerce or readily susceptible of being
used in this way—remained free of impediments. See, e. g.,
Rivers and Harbors Act of 1899, 

; see also
United States v. Appalachian Elec. Power Co., 

,
406–407 (1940); The Daniel Ball, 

 (1871).

  2
     

(s)(3) (2008).
  3
     See Rapanos v. United States, 

 (2006). Neither party
contends that any opinion in Rapanos controls. We agree. See Nichols
v. United States, 

, 745–746 (1994).
   4
     See N. Hines, Nor Any Drop To Drink: Public Regulation of Water
Quality, 

, 196–207 (1966).
660                        SACKETT v. EPA

                          Opinion of the Court

   Congress's early efforts at directly regulating water pol-
lution were tepid. Although the Federal Water Pollution
Control Act of 1948 allowed federal offcials to seek judicial
abatement of pollution in interstate waters, it imposed high
hurdles, such as requiring the consent of the State where
the pollution originated. See 62 Stat. 1156–1157. Despite
repeated amendments over the next two decades, few ac-
tions were brought under this framework.5
   Congress eventually replaced this scheme in 1972 with the
CWA. See 

. The Act prohibits “the discharge
of any pollutant” into “navigable waters. ” 

(a), 1362(12)(A). It broadly defnes the term “ `pol-
lutant' ” to include not only contaminants like “chemical
wastes,” but also more mundane materials like “rock, sand,”
and “cellar dirt.” § 1362(6).
   The CWA is a potent weapon. It imposes what have been
described as “crushing” consequences “even for inadvertent
violations.” Army Corps of Engineers v. Hawkes Co., 578
Page Proof Pending Publication
U. S. 590, 602 (2016) (Kennedy, J., concurring). Property
owners who negligently discharge “pollutants” into covered
waters may face severe criminal penalties including impris-
onment. § 1319(c). These penalties increase for knowing
violations. Ibid. On the civil side, the CWA imposes over
$60,000 in fnes per day for each violation. See Note follow-
ing 

; 

(d); 

(2023) (to be codifed in 

). And due to the Act's
5-year statute of limitations, 

, and expansive
interpretations of the term “violation,” these civil penalties
can be nearly as crushing as their criminal counterparts, see,
e. g., Borden Ranch Partnership v. United States Army
Corps of Engineers, 

 (CA9 2001) (up-
holding Agency decision to count each of 348 passes of a plow
  5
    See Hearings on Activities of the Federal Water Pollution Control Ad-
ministration before the Subcommittee on Air and Water Pollution of the
Senate Committee on Public Works, 90th Cong., 1st Sess., 674 (1967) (re-
porting only one abatement suit between 1948 and 1967).
                    Cite as: 

 (2023)             661

                       Opinion of the Court

by a farmer through “jurisdictional” soil on his farm as a
separate violation), aff 'd by an equally divided Court, 

 (2002) (per curiam).
   The Environmental Protection Agency (EPA) and the
Army Corps of Engineers (Corps) jointly enforce the CWA.
The EPA is tasked with policing violations after the fact,
either by issuing orders demanding compliance or by
bringing civil actions. § 1319(a). The Act also authorizes
private plaintiffs to sue to enforce its requirements.
§ 1365(a). On the front end, both agencies are empowered
to issue permits exempting activity that would otherwise
be unlawful under the Act. Relevant here, the Corps con-
trols permits for the discharge of dredged or fll material
into covered waters. See § 1344(a). The costs of obtaining
such a permit are “signifcant,” and both agencies have ad-
mitted that “the permitting process can be arduous, expen-
sive, and long.” Hawkes Co., 578 U. S., at 594–595, 601.
Success is also far from guaranteed, as the Corps has as-
Page Proof Pending Publication
serted discretion to grant or deny permits based on a long,
nonexclusive list of factors that ends with a catchall mandate
to consider “in general, the needs and welfare of the people.”

(a)(1) (2022).
   Due to the CWA's capacious defnition of “pollutant,” its
low mens rea, and its severe penalties, regulated parties
have focused particular attention on the Act's geographic
scope. While its predecessor encompassed “interstate or
navigable waters,” 

(a) (1970 ed.), the CWA
prohibits the discharge of pollutants into only “navigable wa-
ters,” which it defnes as “the waters of the United States,
including the territorial seas,” 

(a), 1362(7),
(12)(A) (2018 ed.). The meaning of this defnition is the
persistent problem that we must address.

                                 B
  Michael and Chantell Sackett have spent well over a dec-
ade navigating the CWA, and their voyage has been bumpy
662                       SACKETT v. EPA

                         Opinion of the Court

and costly. In 2004, they purchased a small lot near Priest
Lake, in Bonner County, Idaho. In preparation for building
a modest home, they began backflling their property with
dirt and rocks. A few months later, the EPA sent the Sack-
etts a compliance order informing them that their backflling
violated the CWA because their property contained pro-
tected wetlands. The EPA demanded that the Sacketts
immediately “ `undertake activities to restore the Site' ” pur-
suant to a “ `Restoration Work Plan' ” that it provided.
Sackett v. EPA, 

 (2012). The order threat-
ened the Sacketts with penalties of over $40,000 per day if
they did not comply.
   At the time, the EPA interpreted “the waters of the
United States” to include “[a]ll . . . waters” that “could affect
interstate or foreign commerce,” as well as “[w]etlands ad-
jacent” to those waters. 

(s)(3), (7) (2008).
“[A]djacent” was defned to mean not just “bordering” or
“contiguous,” but also “neighboring.” § 230.3(b). Agency
Page Proof Pending Publication
guidance instructed offcials to assert jurisdiction over wet-
lands “adjacent” to non-navigable tributaries when those
wetlands had “a signifcant nexus to a traditional navigable
water.” 6 A “signifcant nexus” was said to exist when
“ `wetlands, either alone or in combination with similarly sit-
uated lands in the region, signifcantly affect the chemical,
physical, and biological integrity' ” of those waters. 2007
Guidance 8 (emphasis added). In looking for evidence of a
“signifcant nexus,” feld agents were told to consider a wide
range of open-ended hydrological and ecological factors.
See id., at 7.
   According to the EPA, the “wetlands” on the Sacketts' lot
are “adjacent to” (in the sense that they are in the same
neighborhood as) what it described as an “unnamed tribu-
tary” on the other side of a 30-foot road. App. 33. That
  6
   EPA & Corps, Clean Water Act Jurisdiction Following the U. S. Su-
preme Court's Decision in Rapanos v. United States & Carabell v. United
States 7–11 (2007) (2007 Guidance).
                   Cite as: 

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                      Opinion of the Court

tributary feeds into a non-navigable creek, which, in turn,
feeds into Priest Lake, an intrastate body of water that the
EPA designated as traditionally navigable. To establish a
signifcant nexus, the EPA lumped the Sacketts' lot together
with the Kalispell Bay Fen, a large nearby wetland complex
that the Agency regarded as “similarly situated.” Accord-
ing to the EPA, these properties, taken together, “signif-
cantly affect” the ecology of Priest Lake. Therefore, the
EPA concluded, the Sacketts had illegally dumped soil and
gravel onto “the waters of the United States.”
   The Sacketts fled suit under the Administrative Proce-
dure Act, 

 et seq., alleging that the EPA lacked
jurisdiction because any wetlands on their property were not
“waters of the United States.” The District Court initially
dismissed the suit, reasoning that the compliance order was
not a fnal agency action, but this Court ultimately held that
the Sacketts could bring their suit under the APA. See
Sackett, 

. After seven years of additional
Page Proof Pending Publication
proceedings on remand, the District Court entered sum-
mary judgment for the EPA. 

 (D Idaho,
Mar. 31, 2019). The Ninth Circuit affrmed, holding that the
CWA covers adjacent wetlands with a signifcant nexus to
traditional navigable waters and that the Sacketts' lot satis-
fed that standard. 

, 1091–1093 (2021).
   We granted certiorari to decide the proper test for deter-
mining whether wetlands are “waters of the United States.”
595 U. S. ––– (2022).
                                II
                                A
   In defning the meaning of “the waters of the United
States,” we revisit what has been “a contentious and diffcult
task.” National Assn. of Mfrs. v. Department of Defense,

, 113–114 (2018). The phrase has sparked dec-
ades of agency action and litigation. In order to resolve the
CWA's applicability to wetlands, we begin by reviewing
this history.
664                     SACKETT v. EPA

                       Opinion of the Court

   The EPA and the Corps initially promulgated different in-
terpretations of “the waters of the United States.” The
EPA defned its jurisdiction broadly to include, for example,
intrastate lakes used by interstate travelers. 

 (1973). Conversely, the Corps, consistent with its
historical authority to regulate obstructions to navigation,
asserted jurisdiction over only traditional navigable waters.

 (1974). But the Corps' narrow defnition
did not last. It soon promulgated new, much broader def-
nitions designed to reach the outer limits of Congress's com-
merce power. See 

, and n. 2 (1977); 40
Fed. Reg. 31324–31325 (1975).
   Eventually the EPA and Corps settled on materially iden-
tical defnitions. See 

 (1980); 47 Fed. Reg.
31810–31811 (1982). These broad defnitions encompassed
“[a]ll . . . waters” that “could affect interstate or foreign com-
merce.” 

(s)(3) (2008). So long as the poten-
Page Proof Pending Publication
tial for an interstate effect was present, the regulation ex-
tended the CWA to, for example, “intrastate lakes, rivers,
streams (including intermittent streams), mudfats, sandfats,
wetlands, sloughs, prairie potholes, wet meadows, playa
lakes, or natural ponds.” 

 The agencies likewise took
an expansive view of the CWA's coverage of wetlands “adja-
cent” to covered waters. § 230.3(s)(7). As noted, they de-
fned “adjacent” to mean “bordering, contiguous, or neigh-
boring” and clarifed that “adjacent” wetlands include those
that are separated from covered waters “by man-made dikes
or barriers, natural river berms, beach dunes, and the like.”
§ 230.3(b). They also specifed that “wetlands” is a technical
term encompassing “those areas that are inundated or satu-
rated by surface or ground water at a frequency and duration
suffcient to support, and that under normal conditions do
support, a prevalence of vegetation typically adapted for
life in saturated soil conditions.” § 230.3(t). The Corps
released what would become a 143-page manual to guide of-
                      Cite as: 

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                          Opinion of the Court

fcers when they determine whether property meets this
defnition.7
   This Court frst construed the meaning of “the waters of
the United States” in United States v. Riverside Bayview
Homes, Inc., 

 (1985). There, we were con-
fronted with the Corps' assertion of authority under the
CWA over wetlands that “actually abut[ted] on a navigable
waterway.” 

. Although we expressed concern
that wetlands seemed to fall outside “traditional notions of
`waters,' ” we nonetheless deferred to the Corps, reason-
ing that “the transition from water to solid ground is not-
necessarily or even typically an abrupt one. ” 

 at
132–133.
   The agencies responded to Riverside Bayview by expand-
ing their interpretations even further. Most notably, they
issued the “migratory bird rule,” which extended jurisdiction
to any waters or wetlands that “are or would be used as [a]
Page Proof Pending Publication
habitat” by migratory birds or endangered species. See 

 (1988); 

 (1986). As the
Corps would later admit, “nearly all waters were jurisdic-
tional under the migratory bird rule.” 8
   In Solid Waste Agency of Northern Cook Cty. v. Army
Corps of Engineers, 

 (2001) (SWANCC), this
Court rejected the migratory bird rule, which the Corps had
used to assert jurisdiction over several isolated ponds lo-
cated wholly within the State of Illinois. Disagreeing with
the Corps' argument that ecological interests supported its
jurisdiction, we instead held that the CWA does not “ex-

  7
    See Corps, Wetlands Delineation Manual (Tech. Rep. Y–87–1, 1987)
(Wetlands Delineation Manual); see also, e. g., Corps, Regional Supplement
to the Corps of Engineers Wetland Delineation Manual: Alaska Region
(Version 2.0) (ERDC/EL Tr–07–24, 2007).
  8
    GAO, Waters and Wetlands: Corps of Engineers Needs To Evaluate Its
District Offce Practices in Determining Jurisdiction 26 (GAO–04–297,
2004) (GAO Report).
666                    SACKETT v. EPA

                      Opinion of the Court

ten[d] to ponds that are not adjacent to open water.” 

 (emphasis deleted).
   Days after our decision, the agencies issued guidance that
sought to minimize SWANCC's impact. They took the view
that this Court's holding was “strictly limited to waters that
are `nonnavigable, isolated, and intrastate' ” and that “feld
staff should continue to exercise CWA jurisdiction to the full
extent of their authority” for “any waters that fall outside of
that category.” 9 The agencies never defned exactly what
they regarded as the “full extent of their authority.” They
instead encouraged local feld agents to make decisions on a
case-by-case basis.
   What emerged was a system of “vague” rules that de-
pended on “locally developed practices.” GAO Report 26.
Deferring to the agencies' localized decisions, lower courts
blessed an array of expansive interpretations of the CWA's
reach. See, e. g., United States v. Deaton, 

(CA4 2003) (holding that a property owner violated the CWA
Page Proof Pending Publication
by piling soil near a ditch 32 miles from navigable waters).
Within a few years, the agencies had “interpreted their juris-
diction over `the waters of the United States' to cover 270-
to-300 million acres” of wetlands and “virtually any parcel of
land containing a channel or conduit . . . through which rain-
water or drainage may occasionally or intermittently fow.”
Rapanos v. United States, 

 (2006) (plural-
ity opinion).
   It was against this backdrop that we granted review in
Rapanos v. United States. The lower court in the principal
case before us had held that the CWA covered wetlands near
ditches and drains that eventually emptied into navigable
waters at least 11 miles away, a theory that had supported
the petitioner's conviction in a related prosecution. 

. Although we vacated that decision, no position
commanded a majority of the Court. Four Justices con-
 9
   EPA & Corps, Memorandum, Supreme Court Ruling Concerning CWA
Jurisdiction Over Isolated Waters 3 (2001) (alteration omitted).
                       Cite as: 

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                           Opinion of the Court

cluded that the CWA's coverage did not extend beyond two
categories: first, certain relatively permanent bodies of
water connected to traditional interstate navigable waters
and, second, wetlands with such a close physical connection
to those waters that they were “as a practical matter indis-
tinguishable from waters of the United States.” 

 (emphasis deleted). Four Justices would have deferred
to the Government's determination that the wetlands at
issue were covered under the CWA. 

 (Stevens, J.,
dissenting). Finally, one Justice concluded that jurisdiction
under the CWA requires a “signifcant nexus” between wet-
lands and navigable waters and that such a nexus exists
where “the wetlands, either alone or in combination with
similarly situated lands in the region, signifcantly affect the
chemical, physical, and biological integrity” of those waters.

 at 779–780 (Kennedy, J., concurring in judgment).
   In the decade following Rapanos, the EPA and the Corps
issued guidance documents that “recognized larger grey
Page Proof Pending Publication
areas and called for more fact-intensive individualized deter-
minations in those grey areas.” 10 As discussed, they in-
structed agency offcials to assert jurisdiction over wetlands
“adjacent” to non-navigable tributaries based on fact-specifc
determinations regarding the presence of a signifcant nexus.
2008 Guidance 8. The guidance further advised offcials to
make this determination by considering a lengthy list of hy-
drological and ecological factors. 

 Echoing what they
had said about the migratory bird rule, the agencies later
admitted that “almost all waters and wetlands across the
country theoretically could be subject to a case-specifc juris-
dictional determination” under this guidance. 

 (2015); see, e. g., Hawkes Co., 578 U. S., at 596 (explain-

  10
     N. Parrillo, Federal Agency Guidance and the Power To Bind: An Em-
pirical Study of Agencies and Industries, 

, 231 (2019);
see 2007 Guidance 7–11; EPA & Corps, Clean Water Act Jurisdiction Fol-
lowing the U. S. Supreme Court's Decision in Rapanos v. United States &
Carabell v. United States 8–12 (2008) (2008 Guidance).
668                     SACKETT v. EPA

                        Opinion of the Court

ing that the Corps found a signifcant nexus between wet-
lands and a river “some 120 miles away”).
   More recently, the agencies have engaged in a furry of
rulemaking defning “the waters of the United States.” In
a 2015 rule, they offered a muscular approach that would
subject “the vast majority of the nation's water features” to
a case-by-case jurisdictional analysis.11 Although the rule
listed a few examples of “waters” that were excluded from
regulation like “[p]uddles” and “swimming pools,” it categor-
ically covered other waters and wetlands, including any
within 1,500 feet of interstate or traditional navigable wa-
ters. 80 Fed. Reg. 37116–37117. And it subjected a wider
range of other waters, including any within 4,000 feet of indi-
rect tributaries of interstate or traditional navigable waters,
to a case-specifc determination for signifcant nexus. 

   The agencies repealed this sweeping rule in 2019. 

. Shortly afterwards, they replaced it with a nar-
Page Proof Pending Publication
rower defnition that limited jurisdiction to traditional navi-
gable waters and their tributaries, lakes, and “adjacent” wet-
lands. 

 (2020). They also narrowed the
defnition of “[a]djacent,” limiting it to wetlands that “[a]but”
covered waters, are fooded by those waters, or are sepa-
rated from those waters by features like berms or barriers.

 This rule too did not last. After granting the EPA's
voluntary motion to remand, a District Court vacated the
rule. See Pascua Yaqui Tribe v. EPA, 

,
957 (D Ariz. 2021).
   The agencies recently promulgated yet another rule at-
tempting to defne waters of the United States. 

 (2023) (to be codifed in 

). Under
that broader rule, traditional navigable waters, interstate
waters, and the territorial seas, as well as their tributaries
and adjacent wetlands, are waters of the United States. 

. So are any “[i]ntrastate lakes and ponds,

  11
   EPA & Dept. of the Army, Economic Analysis of the EPA-Army Clean
Water Rule 11 (2015).
                   Cite as: 

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                      Opinion of the Court

streams, or wetlands” that either have a continuous surface
connection to categorically included waters or have a sig-
nifcant nexus to interstate or traditional navigable waters.
Id., at 3006, 3143. Like the post-Rapanos guidance, the rule
states that a signifcant nexus requires consideration of a list
of open-ended factors. 

, 3144. Finally,
the rule returns to the broad pre-2020 defnition of “adja-
cent.” Ibid.; see supra, at 664. Acknowledging that
“[f]ield work is often necessary to confrm the presence of a
wetland” under these defnitions, the rule instructs local
agents to continue using the Corps' Wetlands Delineation
Manual. 

.

                                B
   With the beneft of a half century of practice under the
CWA, it is worth taking stock of where things stand. The
agencies maintain that the signifcant-nexus test has been
Page Proof Pending Publication
and remains suffcient to establish jurisdiction over “adja-
cent” wetlands. And by the EPA's own admission, “almost
all waters and wetlands” are potentially susceptible to regu-
lation under that test. 

. This puts many
property owners in a precarious position because it is “often
diffcult to determine whether a particular piece of property
contains waters of the United States.” Hawkes Co., 578
U. S., at 594; see 

(t) (2008). Even if a prop-
erty appears dry, application of the guidance in a complicated
manual ultimately decides whether it contains wetlands.
See 

; Wetlands Delineation Manual 84–85
(describing “not . . . atypical” examples of wetlands that peri-
odically lack wetlands indicators); see also Hawkes Co. v.
United States Army Corps of Engineers, 

(CA8 2015) (Kelly, J., concurring) (“This is a unique aspect of
the CWA; most laws do not require the hiring of ex-
pert consultants to determine if they even apply to you or
your property”). And because the CWA can sweep broadly
enough to criminalize mundane activities like moving dirt,
this unchecked definition of “ the waters of the United
670                        SACKETT v. EPA

                          Opinion of the Court

States” means that a staggering array of landowners are at
risk of criminal prosecution or onerous civil penalties.
   What are landowners to do if they want to build on their
property? The EPA recommends asking the Corps for a ju-
risdictional determination, which is a written decision on
whether a particular site contains covered waters. Tr. of
Oral Arg. 86; see Corps, Regulatory Guidance Letter No. 16–
01, at 1 (2016) (RGL 16–01); 

(a)(6), 331.2.
But the Corps maintains that it has no obligation to provide
jurisdictional determinations, RGL 16–01, at 2, and it has
already begun announcing exceptions to the legal effect of
some previous determinations, see 

. Even
if the Corps is willing to provide a jurisdictional determina-
tion, a property owner may fnd it necessary to retain an
expensive expert consultant who is capable of putting to-
gether a presentation that stands a chance of persuading the
Corps.12 And even then, a landowner's chances of success
are low, as the EPA admits that the Corps fnds jurisdiction
Page Proof Pending Publication
approximately 75% of the time. Tr. of Oral Arg. 110.
   If the landowner is among the vast majority who receive
adverse jurisdictional determinations, what then? It would
be foolish to go ahead and build since the jurisdictional deter-
mination might form evidence of culpability in a prosecution
or civil action. The jurisdictional determination could be
challenged in court, but only after the delay and expense
required to exhaust the administrative appeals process. See

(d). And once in court, the landowner would
face an uphill battle under the deferential standards of re-
view that the agencies enjoy. See 

. Another
alternative would be simply to acquiesce and seek a permit

  12
    See 

; Corps, Questions and Answers for Rapanos
and Carabell Decision 16 (2007); J. Finkle, Jurisdictional Determinations:
An Important Battlefeld in the Clean Water Act Fight, 43 Ecology L. Q.
301, 314–315 (2016); K. Gould, Drowning in Wetlands Jurisdictional Deter-
mination Process: Implementation of Rapanos v. United States, 

, 440 (2008).
                   Cite as: 

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                      Opinion of the Court

from the Corps. But that process can take years and cost
an exorbitant amount of money. Many landowners faced
with this unappetizing menu of options would simply choose
to build nothing.
                           III
  With this history in mind, we now consider the extent of
the CWA's geographical reach.

                                A
   We start, as we always do, with the text of the CWA.
Bartenwerfer v. Buckley, 

 (2023). As noted,
the Act applies to “navigable waters,” which had a well-
established meaning at the time of the CWA's enactment.
But the CWA complicates matters by proceeding to defne
“navigable waters” as “the waters of the United States,”
§ 1362(7), which was decidedly not a well-known term of
art. This frustrating drafting choice has led to decades of
Page Proof Pending Publication
litigation, but we must try to make sense of the terms Con-
gress chose to adopt. And for the reasons explained below,
we conclude that the Rapanos plurality was correct: the
CWA's use of “waters” encompasses “only those relatively
permanent, standing or continuously fowing bodies of water
`forming geographic[al] features' that are described in or-
dinary parlance as `streams, oceans, rivers, and lakes.' ” 

 (quoting Webster's New International Diction-
ary 2882 (2d ed. 1954) (Webster's Second); original alter-
ations omitted).
   This reading follows from the CWA's deliberate use of the
plural term “waters.” See 547 U. S., at 732–733. That
term typically refers to bodies of water like those listed
above. See, e. g., Webster's Second 2882; Black's Law Dic-
tionary 1426 (5th ed. 1979) (“especially in the plural, [water]
may designate a body of water, such as a river, a lake, or an
ocean, or an aggregate of such bodies of water, as in the
phrases `foreign waters,' `waters of the United States,' and
the like” (emphasis added)); Random House Dictionary of the
672                    SACKETT v. EPA

                      Opinion of the Court

English Language 2146 (2d ed. 1987) (Random House Dic-
tionary) (defning “waters” as “a. fowing water, or water
moving in waves: The river's mighty waters. b. the sea or
seas bordering a particular country or continent or located
in a particular part of the world” (emphasis deleted)). This
meaning is hard to reconcile with classifying “ ` “lands,” wet
or otherwise, as “waters.” ' ” Rapanos, 

 (plu-
rality opinion) (quoting Riverside Bayview, 

).
   This reading also helps to align the meaning of “the waters
of the United States” with the term it is defning: “navigable
waters.” See Bond v. United States, 

(2014) (“In settling on a fair reading of a statute, it is not
unusual to consider the ordinary meaning of a defned term,
particularly when there is dissonance between that ordinary
meaning and the reach of the defnition”). Although we
have acknowledged that the CWA extends to more than tra-
ditional navigable waters, we have refused to read “naviga-
ble” out of the statute, holding that it at least shows that
Page Proof Pending Publication
Congress was focused on “its traditional jurisdiction over
waters that were or had been navigable in fact or which
could reasonably be so made.” SWANCC, 

;
see also Appalachian Elec., 311 U. S., at 406–407; The Dan-
iel Ball, 

. At a minimum, then, the use of
“navigable” signals that the defnition principally refers to
bodies of navigable water like rivers, lakes, and oceans. See
Rapanos, 

 (plurality opinion).
   More broadly, this reading accords with how Congress has
employed the term “waters” elsewhere in the CWA and in
other laws. The CWA repeatedly uses “waters” in contexts
that confrm the term refers to bodies of open water. See

(i)(2)(D) (“the waters of the Chesapeake
Bay”); § 1268(a)(3)(I) (“the open waters of each of the Great
Lakes”); § 1324(d)(4)(B)(ii) (“lakes and other surface wa-
ters”); § 1330(g)(4)(C)(vii) (“estuarine waters”); § 1343(c)(1)
(“the waters of the territorial seas, the contiguous zone, and
the oceans”); §§ 1346(a)(1), 1375a(a) (“coastal recreation wa-
ters”); § 1370 (state “boundary waters”). The use of “wa-
                         Cite as: 

 (2023)                       673

                             Opinion of the Court

ters” elsewhere in the U. S. Code likewise correlates to riv-
ers, lakes, and oceans.13
   Statutory history points in the same direction. The
CWA's predecessor statute covered “interstate or navigable
waters” and defned “interstate waters” as “all rivers, lakes,
and other waters that fow across or form a part of State
boundaries.” 

(a), 1173(e) (1970 ed.) (em-
phasis added); see also Rivers and Harbors Appropriations
Act of 1899, 

 (codifed, as amended, at 

) (prohibiting unauthorized obstructions “to the naviga-
ble capacity of any of the waters of the United States”).
   This Court has understood the CWA's use of “waters” in
the same way. Even as Riverside Bayview grappled with
whether adjacent wetlands could fall within the CWA's
coverage, it acknowledged that wetlands are not included
in “traditional notions of `waters.' ” 

. It
explained that the term conventionally refers to “hydro-
graphic features” like “rivers” and “streams.” 

.
Page Proof Pending Publication
SWANCC went even further, repeatedly describing the “wa-
ters” covered by the Act as “open water” and suggesting
that “the waters of the United States” principally refers to
traditional navigable waters. 531 U. S., at 168–169, 172.
That our CWA decisions operated under this assumption is
unsurprising. Ever since Gibbons v. Ogden, 

(1824), this Court has used “waters of the United States” to
refer to similar bodies of water, almost always in relation to
ships. Id., at 218 (discussing a vessel's “conduct in the wa-
ters of the United States”).14
  13
      See, e. g., 

 (“the waters of the seacoast . . . the waters
of the lakes”); § 4701(a)(7) (“waters of the Chesapeake Bay”); 

 (“the waters of the Mississippi River and its tributaries”); 43 U. S. C.
§ 390h–8(a) (“the waters of Lake Cheraw, Colorado . . . the waters of the
Arkansas River”); 

 (allowing the Coast Guard to take
control of particular vessels during an emergency in order to “prevent
damage or injury to any harbor or waters of the United States”).
   14
      See, e. g., United States v. Alvarez-Machain, 

(1992) (discussing a treaty “to allow British passenger ships to carry liquor
while in the waters of the United States”); Kent v. Dulles, 

,
674                        SACKETT v. EPA

                          Opinion of the Court

   The EPA argues that “waters” is “naturally read to en-
compass wetlands” because the “presence of water is `uni-
versally regarded as the most basic feature of wetlands.' ”
Brief for Respondents 19. But that reading proves too
much. Consider puddles, which are also defned by the ordi-
nary presence of water even though few would describe them
as “waters.” This argument is also tough to square with
SWANCC, which held that the Act does not cover isolated
ponds, see 

, or Riverside Bayview, which
would have had no need to focus so extensively on the adja-
cency of wetlands to covered waters if the EPA's reading
were correct, see 474 U. S., at 131–135, and n. 8. Finally, it
is also instructive that the CWA expressly “protect[s] the
primary responsibilities and rights of States to prevent, re-
duce, and eliminate pollution” and “to plan the development
and use . . . of land and water resources.” § 1251(b). It is
hard to see how the States' role in regulating water re-
sources would remain “primary” if the EPA had jurisdic-
Page Proof Pending Publication
tion over anything defned by the presence of water. See
County of Maui v. Hawaii Wildlife Fund, 590 U. S. –––, –––
(2020); Rapanos, 

 (plurality opinion).

                                    B
  Although the ordinary meaning of “waters” in § 1362(7)
might seem to exclude all wetlands, we do not view that pro-
vision in isolation. The meaning of a word “may only be-
come evident when placed in context,” FDA v. Brown &

123 (1958) (discussing a prohibition on boarding “vessels of the enemy on
waters of the United States”); New Jersey v. New York City, 

 (1933) (enjoining employees of New York City from dumping garbage
“into the ocean, or waters of the United States, off the coast of New Jer-
sey”); Cunard S. S. Co. v. Mellon, 

 (1923) (holding that
the National Prohibition Act did not apply to “merchant ships when out-
side the waters of the United States”); Keck v. United States, 

, 444–445 (1899) (holding that concealing imported goods on vessels “at
the time of entering the waters of the United States,” without more, did
not constitute smuggling).
                      Cite as: 

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                          Opinion of the Court

Williamson Tobacco Corp., 

 (2000), and
statutory context shows that some wetlands qualify as “wa-
ters of the United States.”
   In 1977, Congress amended the CWA and added
§ 1344(g)(1), which authorizes States to apply to the EPA for
permission to administer programs to issue permits for the
discharge of dredged or fll material into some bodies of
water. In simplifed terms, the provision specifes that state
permitting programs may regulate discharges into (1) any
waters of the United States, (2) except for traditional naviga-
ble waters, (3) “including wetlands adjacent thereto.” 15
   When this convoluted formulation is parsed, it tells us that
at least some wetlands must qualify as “waters of the United
States.” The provision begins with a broad category, “the
waters of the United States,” which we may call category A.
The provision provides that States may permit discharges
into these waters, but it then qualifes that States cannot
permit discharges into a subcategory of A: traditional navi-
Page Proof Pending Publication
gable waters (category B). Finally, it states that a third cat-
egory (category C), consisting of wetlands “adjacent” to
traditional navigable waters, is “includ[ed]” within B. Thus,
States may permit discharges into A minus B, which in-
cludes C. If C (adjacent wetlands) were not part of A (“the
waters of the United States”) and therefore subject to regu-
lation under the CWA, there would be no point in excluding

   15
      This provision states in relevant part: “The Governor of any State
desiring to administer its own individual and general permit program for
the discharge of dredged or fll material into the navigable waters (other
than those waters which are presently used, or are susceptible to use in
their natural condition or by reasonable improvement as a means to trans-
port interstate or foreign commerce shoreward to their ordinary high
water mark, including all waters which are subject to the ebb and fow of
the tide shoreward to their mean high water mark, or mean higher high
water mark on the west coast, including wetlands adjacent thereto) within
its jurisdiction may submit to the Administrator a full and complete de-
scription of the program it proposes to establish and administer under
State law or under an interstate compact.” 

(g)(1).
676                    SACKETT v. EPA

                      Opinion of the Court

them from that category. See Riverside Bayview, 

 (recognizing that § 1344(g) “at least suggest[s]
strongly that the term `waters' as used in the Act does not
necessarily exclude `wetlands' ”); Rapanos, 

(opinion of Kennedy, J.). Thus, § 1344(g)(1) presumes that
certain wetlands constitute “waters of the United States.”
   But what wetlands does the CWA regulate? Section
1344(g)(1) cannot answer that question alone because it is
not the operative provision that defnes the Act's reach. See
Riverside Bayview, 

. Instead, we
must harmonize the reference to adjacent wetlands in
§ 1344(g)(1) with “the waters of the United States,” § 1362(7),
which is the actual term we are tasked with interpreting.
The formulation discussed above tells us how: because the
adjacent wetlands in § 1344(g)(1) are “includ[ed]” within “the
waters of the United States,” these wetlands must qualify as
“waters of the United States” in their own right. In other
Page Proof Pending Publication
words, they must be indistinguishably part of a body of
water that itself constitutes “waters” under the CWA. See
supra, at 671.
   This understanding is consistent with § 1344(g)(1)'s use of
“adjacent.” Dictionaries tell us that the term “adjacent”
may mean either “contiguous” or “near.” Random House
Dictionary 25; see Webster's Third New International Dic-
tionary 26 (1976); see also Oxford American Dictionary &
Thesaurus 16 (2d ed. 2009) (listing “adjoining” and “neigh-
boring” as synonyms of “adjacent”). But “construing statu-
tory language is not merely an exercise in ascertaining `the
outer limits of a word's defnitional possibilities,' ” FCC v.
AT&T Inc., 

 (2011) (alterations omitted),
and here, “only one . . . meanin[g] produces a substantive
effect that is compatible with the rest of the law,” United
Sav. Assn. of Tex. v. Timbers of Inwood Forest Associates,
Ltd., 

 (1988). Wetlands that are separate
from traditional navigable waters cannot be considered part
of those waters, even if they are located nearby.
                    Cite as: 

 (2023)             677

                       Opinion of the Court

   In addition, it would be odd indeed if Congress had tucked
an important expansion to the reach of the CWA into con-
voluted language in a relatively obscure provision concern-
ing state permitting programs. We have often remarked
that Congress does not “hide elephants in mouseholes” by
“alter[ing] the fundamental details of a regulatory scheme in
vague terms or ancillary provisions.” Whitman v. Ameri-
can Trucking Assns., Inc., 

 (2001). We
cannot agree with such an implausible interpretation here.
   If § 1344(g)(1) were read to mean that the CWA applies
to wetlands that are not indistinguishably part of otherwise
covered “waters of the United States,” see supra, at 671, it
would effectively amend and substantially broaden § 1362(7)
to defne “navigable waters” as “waters of the United States
and adjacent wetlands.” But § 1344(g)(1)'s use of the term
“including” makes clear that it does not purport to do—and
in fact, does not do—any such thing. See National Assn.
Page Proof Pending Publication
of Home Builders v. Defenders of Wildlife, 

,
662–664, and n. 8 (2007) (recognizing that implied amend-
ments require “ `clear and manifest' ” evidence of congres-
sional intent). It merely refects Congress's assumption
that certain “adjacent” wetlands are part of “waters of the
United States.”
   This is the thrust of observations in decisions going all the
way back to Riverside Bayview. In that case, we deferred
to the Corps' decision to regulate wetlands actually abut-
ting a navigable waterway, but we recognized “the inherent
diffculties of defning precise bounds to regulable waters.”

; see also 

 (noting that “the transi-
tion from water to solid ground is not necessarily or even
typically an abrupt one” due to semi-aquatic features like
shallows and swamps). In such a situation, we concluded,
the Corps could reasonably determine that wetlands “adjoin-
ing bodies of water” were part of those waters. 

,
and n. 9; see also SWANCC, 531 U. S., at 167 (recognizing
that Riverside Bayview “held that the Corps had . . . juris-
678                        SACKETT v. EPA

                          Opinion of the Court

diction over wetlands that actually abutted on a navigable
waterway”).
   In Rapanos, the plurality spelled out clearly when adja-
cent wetlands are part of covered waters. It explained that
“waters” may fairly be read to include only those wetlands
that are “as a practical matter indistinguishable from waters
of the United States,” such that it is “diffcult to determine
where the `water' ends and the `wetland' begins.” 

 (emphasis deleted). That occurs when wetlands
have “a continuous surface connection to bodies that are `wa-
ters of the United States' in their own right, so that there is
no clear demarcation between `waters' and wetlands.” 

; cf. 

(5) (defning “coastal waters” to
include wetlands “having unimpaired connection with the
open sea up to the head of tidal infuence”). We agree with
this formulation of when wetlands are part of “the waters of
the United States.” We also acknowledge that temporary
interruptions in surface connection may sometimes occur be-
Page Proof Pending Publication
cause of phenomena like low tides or dry spells.16
   In sum, we hold that the CWA extends to only those wet-
lands that are “as a practical matter indistinguishable from
waters of the United States.” Rapanos, 

(plurality opinion) (emphasis deleted). This requires the
party asserting jurisdiction over adjacent wetlands to estab-
lish “frst, that the adjacent [body of water constitutes] . . .
`water[s] of the United States,' (i. e., a relatively permanent
body of water connected to traditional interstate navigable
waters); and second, that the wetland has a continuous sur-
face connection with that water, making it diffcult to deter-

  16
     Although a barrier separating a wetland from a water of the United
States would ordinarily remove that wetland from federal jurisdiction, a
landowner cannot carve out wetlands from federal jurisdiction by illegally
constructing a barrier on wetlands otherwise covered by the CWA.
Whenever the EPA can exercise its statutory authority to order a barri-
er's removal because it violates the Act, see §§ 1319(a)–(b), that unlawful
barrier poses no bar to its jurisdiction.
                   Cite as: 

 (2023)            679

                      Opinion of the Court

mine where the `water' ends and the `wetland' begins.” 

.
                            IV
   The EPA resists this reading of § 1362(7) and instead asks
us to defer to its understanding of the CWA's jurisdictional
reach, as set out in its most recent rule defning “the waters
of the United States.” See 

. This rule,
as noted, provides that “adjacent wetlands are covered by
the Act if they `possess a “signifcant nexus” to' traditional
navigable waters.” Brief for Respondents 32 (quoting Rap-
anos, 

 (opinion of Kennedy, J.)); see 

. And according to the EPA, wetlands are “adja-
cent” when they are “neighboring” to covered waters, even
if they are separated from those waters by dry land. Brief
for Respondents 20; 

.

                                A

Page       Proof
   For reasons         Pending
               already explained,         Publication
                                  this interpretation
sistent with the text and structure of the CWA. Beyond
                                                      is incon-

that, it clashes with “background principles of construction”
that apply to the interpretation of the relevant statutory pro-
visions. Bond, 

. Under those presump-
tions, the EPA must provide clear evidence that it is author-
ized to regulate in the manner it proposes.

                                1
   First, this Court “require[s] Congress to enact exceedingly
clear language if it wishes to signifcantly alter the balance
between federal and state power and the power of the
Government over private property.” United States Forest
Service v. Cowpasture River Preservation Assn., 590 U. S.
–––, ––– – ––– (2020); see also Bond, 

. Regu-
lation of land and water use lies at the core of traditional
state authority. See, e. g., SWANCC, 531 U. S., at 174 (citing
Hess v. Port Authority Trans-Hudson Corporation, 

 (1994)); Tarrant Regional Water Dist. v. Herr-
680                    SACKETT v. EPA

                      Opinion of the Court

mann, 

 (2013). An overly broad interpre-
tation of the CWA's reach would impinge on this authority.
The area covered by wetlands alone is vast—greater than
the combined surface area of California and Texas. And the
scope of the EPA's conception of “the waters of the United
States” is truly staggering when this vast territory is sup-
plemented by all the additional area, some of which is gener-
ally dry, over which the Agency asserts jurisdiction. Par-
ticularly given the CWA's express policy to “preserve” the
States' “primary” authority over land and water use,
§ 1251(b), this Court has required a clear statement from
Congress when determining the scope of “the waters of the
United States.” SWANCC, 531 U. S., at 174; accord, Ra-
panos, 

 (plurality opinion).
   The EPA, however, offers only a passing attempt to square
its interpretation with the text of § 1362(7), and its “signif-
cant nexus” theory is particularly implausible. It suggests
that the meaning of “the waters of the United States” is so
Page Proof Pending Publication
“broad and unqualifed” that, if viewed in isolation, it would
extend to all water in the United States. Brief for Respond-
ents 32. The EPA thus turns to the “signifcant nexus” test
in order to reduce the clash between its understanding of
“the waters of the United States” and the term defned by
that phrase, i. e., “navigable waters.” As discussed, how-
ever, the meaning of “waters” is more limited than the EPA
believes. See supra, at 671. And, in any event, the CWA
never mentions the “signifcant nexus” test, so the EPA has
no statutory basis to impose it. See Rapanos, 547 U. S., at
755–756 (plurality opinion).
                               2
   Second, the EPA's interpretation gives rise to serious
vagueness concerns in light of the CWA's criminal penalties.
Due process requires Congress to defne penal statutes
“ `with suffcient defniteness that ordinary people can under-
stand what conduct is prohibited' ” and “ `in a manner that
does not encourage arbitrary and discriminatory enforce-
                   Cite as: 

 (2023)           681

                      Opinion of the Court

ment.' ” McDonnell v. United States, 

, 576
(2016) (quoting Skilling v. United States, 

, 402–
403 (2010)). Yet the meaning of “waters of the United
States” under the EPA's interpretation remains “hopelessly
indeterminate.” Sackett, 

 (Alito, J., concur-
ring); accord, Hawkes Co., 578 U. S., at 602 (opinion of Ken-
nedy, J.).
  The EPA contends that the only thing preventing it from
interpreting “waters of the United States” to “conceivably
cover literally every body of water in the country” is the
signifcant-nexus test. Tr. of Oral Arg. 70–71; accord, Brief
for Respondents 32. But the boundary between a “signif-
cant” and an insignifcant nexus is far from clear. And to
add to the uncertainty, the test introduces another vague
concept—“similarly situated” waters—and then assesses the
aggregate effect of that group based on a variety of open-
ended factors that evolve as scientific understandings
change. This freewheeling inquiry provides little notice to
Page Proof Pending Publication
landowners of their obligations under the CWA. Facing se-
vere criminal sanctions for even negligent violations, prop-
erty owners are “left `to feel their way on a case-by-case
basis.' ” Sackett, 

 (quoting Rapanos, 

 (Roberts, C. J., concurring)). Where a penal
statute could sweep so broadly as to render criminal a host
of what might otherwise be considered ordinary activities,
we have been wary about going beyond what “Congress cer-
tainly intended the statute to cover.” Skilling, 

.
  Under these two background principles, the judicial task
when interpreting “the waters of the United States” is to
ascertain whether clear congressional authorization exists
for the EPA's claimed power. The EPA's interpretation falls
far short of that standard.
                              B
  While mustering only a weak textual argument, the EPA
justifes its position on two other grounds. It primarily
682                     SACKETT v. EPA

                       Opinion of the Court

claims that Congress implicitly ratifed its interpretation of
“adjacent” wetlands when it adopted § 1344(g)(1). Thus, it
argues that “waters of the United States” covers any wet-
lands that are “bordering, contiguous, or neighboring” to
covered waters. 

. The principal opinion
concurring in the judgment adopts the same position. See
post, at 723–725 (Kavanaugh, J., concurring in judgment).
The EPA notes that the Corps had promulgated regulations
adopting that interpretation before Congress amended the
CWA in 1977 to include the reference to “adjacent” wetlands
in § 1344(g)(1). See 

. This term, the
EPA contends, was “ ` “obviously transplanted from” ' ” the
Corps' regulations and thus incorporates the same defnition.
Brief for Respondents 22 (quoting Taggart v. Lorenzen, 587
U. S. –––, ––– (2019)).
   This argument fails for at least three reasons. First, as
we have explained, the text of §§ 1362(7) and 1344(g)(1)
Page Proof Pending Publication
shows that “adjacent” cannot include wetlands that are not
part of covered “waters.” See supra, at 678–679.
   Second, this ratifcation theory cannot be reconciled with
our cases. We have repeatedly recognized that § 1344(g)(1)
“ `does not conclusively determine the construction to be
placed on . . . the relevant defnition of “navigable waters.” ' ”
SWANCC, 531 U. S., at 171 (quoting Riverside Bayview, 

); accord, Rapanos, 547 U. S., at 747–748,
n. 12 (plurality opinion). Additionally, SWANCC rejected
the closely analogous argument that Congress ratifed the
Corps' defnition of “waters of the United States” by includ-
ing “ `other . . . waters' ” in § 1344(g)(1). 531 U. S., at 168–
171. And yet, the EPA's argument would require us to hold
that § 1344(g)(1) actually did amend the defnition of “navi-
gable waters” precisely for the reasons we re jected in
SWANCC.
   Third, the EPA cannot provide the sort of “overwhelming
evidence of acquiescence” necessary to support its argument
in the face of Congress's failure to amend § 1362(7). Id., at
                  Cite as: 

 (2023)           683

                     Opinion of the Court

169–170, n. 5. We will infer that a term was “ `transplanted
from another legal source' . . . only when a term's meaning
was `well-settled' before the transplantation.” Kemp v.
United States, 596 U. S. –––, ––– – ––– (2022). Far from
being well settled, the Corps' defnition was promulgated
mere months before the CWA became law, and when the
Corps adopted that defnition, it candidly acknowledged the
“rapidly changing nature of [its] regulatory programs.” 

. Tellingly, even the EPA would not adopt
that defnition for several more years. See 

 (1980). This situation is a far cry from any in which
we have found ratifcation. See, e. g., George v. McDonough,
596 U. S. –––, ––– (2022) (fnding ratifcation when “Congress
used an unusual term that had a long regulatory history in
[the] very [regulatory] context” at issue).
   The EPA also advances various policy arguments about
the ecological consequences of a narrower defnition of adja-
cent. But the CWA does not defne the EPA's jurisdiction
Page Proof Pending Publication
based on ecological importance, and we cannot redraw the
Act's allocation of authority. See Rapanos, 

(plurality opinion). “The Clean Water Act anticipates a
partnership between the States and the Federal Govern-
ment.” Arkansas v. Oklahoma, 

 (1992).
States can and will continue to exercise their primary au-
thority to combat water pollution by regulating land and
water use. See, e. g., Brief for Farm Bureau of Arkansas
et al. as Amici Curiae 17–27.

                               V
  Nothing in the separate opinions fled by Justice Kava-
naugh and Justice Kagan undermines our analysis. Jus-
tice Kavanaugh claims that we have “rewrit[ten]” the
CWA, post, at 725 (opinion concurring in judgment), and Jus-
tice Kagan levels similar charges, post, at 712–713 (opinion
concurring in judgment). These arguments are more than
unfounded. We have analyzed the statutory language in
684                    SACKETT v. EPA

                     Thomas, J., concurring

detail, but the separate opinions pay no attention whatsoever
to § 1362(7), the key statutory provision that limits the
CWA's geographic reach to “ the waters of the United
States.” Thus, neither separate opinion even attempts to
explain how the wetlands included in their interpretation fall
within a fair reading of “waters.” Textualist arguments
that ignore the operative text cannot be taken seriously.

                              VI
  In sum, we hold that the CWA extends to only those “wet-
lands with a continuous surface connection to bodies that are
`waters of the United States' in their own right,” so that they
are “indistinguishable” from those waters. Rapanos, 

 (plurality opinion) (emphasis deleted); see
supra, at 678–679. This holding compels reversal here.
The wetlands on the Sacketts' property are distinguishable
from any possibly covered waters.
Page Proof Pending
           *  *  * Publication
  We reverse the judgment of the United States Court of
Appeals for the Ninth Circuit and remand the case for fur-
ther proceedings consistent with this opinion.

                                              It is so ordered.
  Justice Thomas, with whom Justice Gorsuch joins,
concurring.
   I join the Court's opinion in full. The Clean Water Act
(CWA) confnes the Federal Government's jurisdiction to
“ `navigable waters,' ” defned as “the waters of the United
States.” 

(a), 1362(7), (12). And the Court
correctly holds that the term “waters” reaches “ `only those
relatively permanent, standing or continuously fowing bod-
ies of water “forming geographic[al] features” that are de-
scribed in ordinary parlance as “streams, oceans, rivers, and
lakes.” ' ” Ante, at 671 (quoting Rapanos v. United States,

 (2006) (plurality opinion)). It also cor-
                   Cite as: 

 (2023)           685

                     Thomas, J., concurring

rectly holds that for a wetland to fall within this defnition,
it must share a “ `continuous surface connection to bodies
that are “waters of the United States” in their own right' ”
such that “ `there is no clear demarcation between “waters”
and wetlands.' ” Ante, at 678 (quoting Rapanos, 

 (plurality opinion)).
   However, like the Rapanos plurality before it, the Court
focuses only on the term “waters”; it does not determine the
extent to which the CWA's other jurisdictional terms—“navi-
gable” and “of the United States”—limit the reach of the
statute. Ante, at 671–674; Rapanos, 

 (plu-
rality opinion). I write separately to pick up where the
Court leaves off.
                               I
   The CWA's jurisdictional terms have a long pedigree and
are bound up with Congress' traditional authority over the
channels of interstate commerce. Solid Waste Agency of
Page Proof Pending Publication
Northern Cook Cty. v. Army Corps of Engineers, 

, and n. 3, 172, 173–174 (2001) (SWANCC). That tra-
ditional authority was limited in two ways. First, the water
had to be capable of being used as a highway for interstate
or foreign commerce. Second, Congress could regulate such
waters only for purposes of their navigability—by, for exam-
ple, regulating obstructions hindering navigable capacity.
By the time of the CWA's enactment, the New Deal era argu-
ably had relaxed the second limitation; Congress could regu-
late navigable waters for a wider range of purposes. But,
critically, the statutory terms “navigable waters,” “navigable
waters of the United States,” and “waters of the United
States” were still understood as invoking only Congress' au-
thority over waters that are, were, or could be used as high-
ways of interstate or foreign commerce. The CWA was
enacted, and must be understood, against that key backdrop.

                                A
  As the Court correctly states, “land and water use lies at
the core of traditional state authority.” Ante, at 679; see
686                    SACKETT v. EPA

                     Thomas, J., concurring

also ante, at 659. Prior to Independence, the Crown pos-
sessed sovereignty over navigable waters in the Colonies,
sometimes held in trust by colonial authorities. See R.
Adler, The Ancient Mariner of Constitutional Law: The His-
torical, Yet Declining Role of Navigability, 

, 1656–1659 (2013); R. Walston, The Federal
Commerce and Navigation Powers: Solid Waste Agency of
Northern Cook County's Undecided Constitutional Issue, 

, 721 (2002) (Walston). Upon Inde-
pendence, this sovereignty was transferred to each of the 13
fully sovereign States. See Martin v. Lessee of Waddell, 

 (1842) (“[W]hen the Revolution took place, the
people of each state became themselves sovereign; and in
that character hold the absolute right to all their navigable
waters and the soils under them for their own common use,
subject only to the rights since surrendered by the Constitu-
tion to the general government”). Thus, today, States enjoy
Page Proof Pending Publication
primary sovereignty over their waters, including navigable
waters—stemming either from their status as independent
sovereigns following Independence, ibid., or their later ad-
mission to the Union on an equal footing with the original
States, see Lessee of Pollard v. Hagan, 

 (1845)
(“The shores of navigable waters, and the soils under them,
were not granted by the Constitution to the United States,
but were reserved to the states respectively. . . . The new
states have the same rights, sovereignty, and jurisdiction
over this subject as the original states”); see also M. Starr,
Navigable Waters of the United States—State and National
Control, 

, 169–170 (1921). The Federal
Government therefore possesses no authority over navigable
waters except that granted by the Constitution.
   The Federal Government's authority over certain naviga-
ble waters is granted and limited by the Commerce Clause,
which grants Congress power to “regulate Commerce with
foreign Nations, and among the several States, and with the
Indian Tribes.” Art. I, § 8, cl. 3. From the beginning, it
                   Cite as: 

 (2023)           687

                     Thomas, J., concurring

was understood that “[t]he power to regulate commerce, in-
cludes the power to regulate navigation,” but only “as con-
nected with the commerce with foreign nations, and among
the states.” United States v. Coombs, 

 (1838)
(Story, J., for the Court); accord, Gibbons v. Ogden, 

 (1824) (“All America understands . . . the word `com-
merce,' to comprehend navigation. It was so understood,
and must have been so understood, when the constitution
was framed”); see also R. Barnett, The Original Meaning of
the Commerce Clause, 

, 125–126 (2001)
(Barnett); R. Natelson, The Legal Meaning of “Commerce”
in the Commerce Clause, 

, 807–810
(2006). In fact, “shipping . . . was at that time the indis-
pensable means for the movement of goods.” Barnett 123.
The Commerce Clause thus vests Congress with a limited
authority over what we now call the “channels of inter-
state commerce.” United States v. Lopez, 

,
Page Proof Pending Publication
558–559 (1995); see also American Trucking Assns., Inc. v.
Los Angeles, 

, 656–657 (2013) (Thomas, J.,
concurring).
   This federal authority, however, does not displace States'
traditional sovereignty over their waters. “The power to
regulate commerce comprehends the control for that pur-
pose, and to the extent necessary, of all the navigable waters
of the United States which are accessible from a State other
than those in which they lie.” Gilman v. Philadelphia, 

, 724–725 (1866) (emphasis added). And, tradition-
ally, this limited authority was confned to regulation of the
channels of interstate commerce themselves. Corfeld v.
Coryell, 

, 550–551 (No. 3,230) (CC ED Pa. 1823)
(Washington, J., for the Court). It encompassed only “the
power to keep them open and free from any obstruction to
their navigation” and “to remove such obstructions when
they exist.” Gilman, 

. Thus, any activity
that “interferes with, obstructs, or prevents such commerce
and navigation, though done on land, may be punished by
688                    SACKETT v. EPA

                     Thomas, J., concurring

congress.” Coombs, 

. But, activities that
merely “affect” water-based commerce, such as those regu-
lated by “[i]nspection laws, quarantine laws, health laws of
every description, as well as laws for regulating the internal
commerce of a State,” are not within Congress' channels-
of-commerce authority. Gibbons, 

; see also
Corfeld, 

.
   This understanding of the limits of Congress' channels-of-
commerce authority prevailed through the end of the 19th
century. The Court's cases consistently recognized that
Congress has authority over navigable waters for only the
limited “purpose of regulating and improving navigation.”
Gibson v. United States, 

, 271–272 (1897); see
also Port of Seattle v. Oregon & Washington R. Co., 

 (1921) (“The right of the United States in the naviga-
ble waters within the several States is limited to the control
thereof for purposes of navigation”). And, this Court was
Page Proof Pending Publication
careful to reaffrm that “technical title to the beds of the
navigable rivers of the United States is either in the States
in which the rivers are situated, or in the owners of the land
bordering upon such rivers” as determined by “local law.”
United States v. Chandler-Dunbar Water Power Co., 

 (1913).
   The River and Harbor Acts of 1890, 1894, and 1899 illus-
trate the limits of the channels-of-commerce authority. The
1890 Act authorizes the Secretary of War to “prohibi[t]” “the
creation of any obstruction, not affrmatively authorized by
law, to the navigable capacity of any waters, in respect of
which the United States has jurisdiction.” § 10, 

.
The 1894 Act made it unlawful to deposit matter into “any
harbor or river of the United States” that the Federal Gov-
ernment has appropriated money to improve and prohibited
injuring improvements built by the United States in “any of
its navigable waters.” § 6, 

.
   Congress consolidated and expanded these authorities in
the 1899 Act. Section 10 of the Act prohibits “[t]he creation
                   Cite as: 

 (2023)           689

                     Thomas, J., concurring

of any obstruction . . . to the navigable capacity of any of
the waters of the United States,” requires a permit to build
“structures in any . . . water of the United States,” and
makes it unlawful “to excavate or fll, or in any manner to
alter or modify the course, location, condition, or capacity”
of any water, “within the limits of any breakwater, or of the
channel of any navigable water of the United States.” 

 (codifed, as amended, at 

). In ad-
dition, § 13 of the Act, sometimes referred to as the “Refuse
Act,” prohibits throwing, discharging, or depositing “any re-
fuse matter . . . into any navigable water of the United
States, or into any tributary of any navigable water from
which the same shall foat or be washed into such navigable
water.” 

 (codifed, as amended, at 

). Section 13 also prohibits depositing material “on the
bank of any navigable water, or on the bank of any tributary
of any navigable water, where the same shall be liable to be
Page Proof Pending Publication
washed into such navigable water . . . whereby navigation
shall or may be impeded or obstructed.” 

   Three things stand out about these provisions. First,
they use the terms “navigable water,” “water of the United
States,” and “navigable water of the United States” inter-
changeably. 

 and 407; see also V. Al-
brecht & S. Nickelsburg, Could SWANCC Be Right? A New
Look at the Legislative History of the Clean Water Act, 32
Env. L. Rev. 11042, 11044 (2002) (Albrecht & Nickelsburg).
As a result, courts have done the same in decisions interpret-
ing the River and Harbor Acts. See, e. g., United States v.
Stoeco Homes, Inc., 

, 608–609 (CA3 1974); New
England Dredging Co. v. United States, 

, 933–934
(CA1 1906); Blake v. United States, 

, 587–
588 (ED Va. 1960).
   Second, Congress asserted its authority only to the extent
that obstructions or refuse matter could impede navigation
or navigable capacity. Thus, in United States v. Rio Grande
Dam & Irrigation Co., 

 (1899), this Court recog-
690                        SACKETT v. EPA

                         Thomas, J., concurring

nized that any “act sought to be enjoined” under the 1890
Act must be “one which fairly and directly tends to obstruct
(that is, interfere with or diminish) the navigable capacity
of a stream.” 

; accord, Lake Shore & Michigan
Southern R. Co. v. Ohio, 

 (1897) (holding
that federal jurisdiction over “navigable waters” was limited
to preventing “interfering with commerce”). Similarly, in
Wisconsin v. Illinois, 

 (1929), this Court in-
terpreted the 1899 Act in light of the constitutional prohibi-
tion on Congress “arbitrarily destroy[ing] or impair[ing] the
rights of riparian owners by legislation which has no real or
substantial relation to the control of navigation or appropri-
ateness to that end.” 

.1 The touchstone, thus,
remained actual navigation.
   Third, § 13 of the Act requires some form of surface water
connection between a tributary and traditionally navigable
waters. See 

 (prohibiting depositing refuse
“into any tributary of any navigable water from which the
Page Proof Pending Publication
same shall foat or be washed into such navigable water”).
To be sure, the Refuse Act also prohibits leaving refuse “on
the bank of any navigable water, or on the bank of any tribu-
tary of any navigable water, where the same shall be liable
to be washed into such navigable water.” 

 But, this
prohibition refects nothing more than Congress' traditional

   1
     Courts had long carefully enforced limits on Congress' navigation au-
thority in prosecutions brought under the Act of July 7, 1838, ch. 191, 

 (Steamboat Acts of 1838), which prohibited the transportation of
goods “upon the bays, lakes, rivers, or other navigable waters of the
United States” by certain steamboats. See, e. g., The Seneca, 

 (No. 16,251) (DC Wis. 1861); see also The James Morrison, 

 (No. 15,465) (DC Mo. 1846) (holding that the 1838 Act did not
reach a ship whose “employment ha[d] no other than a remote connection
with `commerce or navigation among the several states;' no more connec-
tion than has the farmer who cultivates hemp, tobacco or cotton for a
market in other states—the miner who digs and smelts lead—the manufac-
turer who manufactures for the same market, or the traveler who intends
purchasing any of these articles”).
                       Cite as: 

 (2023)                     691

                          Thomas, J., concurring

authority to regulate acts done on land that directly impair
the navigability of traditionally navigable waters. See Rio
Grande Dam & Irrigation Co., 

 (explaining
that the Act reaches “any obstruction to the navigable capac-
ity, and anything, wherever done or however done, . . . which
tends to destroy the navigable capacity of one of the naviga-
ble waters of the United States”); see also Northern Pacifc
R. Co. v. United States, 

 (CA8 1900); Coombs,

. It does not mean that the land itself is a
navigable water.2
   The history of federal regulation of navigable waters dem-
onstrates that Congress' authority over navigation, as tradi-
tionally understood, was narrow but deep. It only applied
to a discrete set of navigable waters and could only be used
to keep those waters open for interstate commerce. See
Port of Seattle, 

; Rio Grande Dam & Irriga-
tion Co., 

. Yet, where Congress had author-
ity, it displaced the States' traditional sovereignty over their
Page Proof Pending Publication
navigable waters and allowed Congress to regulate activities
even on land that could directly cause obstructions to naviga-
ble capacity. Gilman, 3 Wall., at 724–725; Coombs, 

.
   In light of the depth of this new federal power, it was
carefully limited—mere “effects” on interstate commerce
were not suffcient to trigger Congress' navigation authority.
As one District Court presciently observed in interpreting
the term “navigable waters of the United States” in the
Steamboat Act of 1838:
      “To make a particular branch of commerce or trade
      within a state, a part of the commerce among the several
  2
   The early 20th century also saw the Reclamation Act of 1902, ch. 1093,

; Federal Power Act, ch. 285, 

; Oil Pollution Act,
1924, ch. 316, 

; and Flood Control Act of 1936, ch. 688, 

, all of which relied on navigability. See Walston 724–726. Although
the Acts were also designed to achieve incidental benefts such as pollution
control, Congress located its authority in preserving navigation. 

692                        SACKETT v. EPA

                         Thomas, J., concurring

      states, it would not be suffcient that it was remotely
      connected with that commerce among the several states;
      for almost everything and every occupation and employ-
      ment in life are remotely connected with that commerce
      or navigation. And if Congress has the right to regu-
      late every employment or pursuit thus remotely con-
      nected with that commerce, of which they have the con-
      trol, then it has the right to regulate nearly the entire
      business and employment of the citizens of the several
      states. . . . Yet, if Congress has the power to regulate
      all these employments, and a thousand others equally
      connected with that commerce, then it can regulate
      nearly all the concerns of life, and nearly all the employ-
      ments of the citizens of the several states; and the state
      governments might as well be abolished. It is not suf-
      fcient, then, that navigation, or trade, or business of any
      kind, within a state, be remotely connected, or, perhaps,
      connected at all with `commerce with foreign nations, or
Page Proof Pending Publication
      among the several states, or with the Indian tribes,' it
      should be a part of that commerce, to authorize congress
      to regulate it.” The James Morrison, 

 (No. 15,465) (DC Mo. 1846).
The Court's observation that “federal regulation was largely
limited to ensuring that `traditional navigable waters' . . .
remained free of impediments,” ante, at 659, thus does no
more than refect the original understanding of the federal
authority over navigable waters.

                                    B
  As noted above, the scope of Congress' authority over wa-
ters was defned by the traditional concept of navigability,
imported with signifcant modifcations from the English
common law.3 Thus, Congress could regulate only “naviga-
  3
   The English rule tied navigability to the ebb and fow of the tides, but
began to be eroded in America as early as the Northwest Ordinance of
1787 due to the superior commercial capacity of American inland riv-
                       Cite as: 

 (2023)                   693

                         Thomas, J., concurring

ble waters.” Consistent with that backdrop, the term “navi-
gable waters”—used interchangeably with “waters of the
United States” and “navigable waters of the United
States”—referred to the waters subject to Congress' tradi-
tional authority over navigable waters until the enactment
of the CWA.
                             1
   The term “navigable waters” has been in use since the
founding to refer to the highways of commerce that were
key to the Nation's development. Great cities like Phila-
delphia and St. Louis emerged at frst as commercial ports
along these navigable waters. The Framers recognized that
“Providence has in a particular manner blessed” our country
with “[a] succession of navigable waters” that “bind [the Na-
tion] together; while the most noble rivers in the world,
running at convenient distances, present [Americans] with
highways for the easy communication of friendly aids and
Page Proof Pending Publication
the mutual transportation and exchange of their various
commodities.” The Federalist No. 2, p. 38 (C. Rossiter ed.
1961) (J. Jay). These “vast rivers, stretching far inland”
have been of “transcendent importance” to our Nation's eco-
nomic expansion by forming “great highways” for commerce.
L. Houck, Law of Navigable Rivers xiii (1868).
   This Court authoritatively set out the scope of the term
“navigable waters of the United States” in the seminal case
of The Daniel Ball, 

 (1871). That case arose
under the Steamboat Act of 1838, which prohibited the trans-
portation of goods “upon the bays, lakes, rivers, or other nav-

ers. See The Daniel Ball, 

 (1871); Propeller Genesee
Chief v. Fitzhugh, 

, 454–457 (1852); see also Economy Light &
Power Co. v. United States, 

 (1921) (“[I]t is curious and
interesting that the importance of these inland waterways, and the inap-
propriateness of the tidal test in defning our navigable waters, was thus
recognized by the Congress of the Confederation [in the Northwest Ordi-
nance] more than 80 years before this court decided The Daniel Ball . . .
and more than 60 years before The Propeller Genesee Chief ”).
694                     SACKETT v. EPA

                      Thomas, J., concurring

igable waters of the United States.” § 2, 

. This
Court held that the term “navigable” refers to waters that
are “navigable in fact,” meaning that “they are used, or are
susceptible of being used, in their ordinary condition, as
highways for commerce, over which trade and travel are or
may be conducted in the customary modes of trade and
travel on water.” The Daniel Ball, 

. The
Court then explained that navigable waters are “of the
United States,” “in contradistinction from the navigable wa-
ters of the States, when they form in their ordinary condition
by themselves, or by uniting with other waters, a continued
highway over which commerce is or may be carried on with
other States or foreign countries in the customary modes in
which such commerce is conducted by water.” Ibid.; see
also The Montello, 

 (1871) (“If . . . the river
is not of itself a highway for commerce with other States
or foreign countries, or does not form such highway by its
Page Proof Pending Publication
connection with other waters, and is only navigable between
different places within the State, then it is not a navigable
water of the United States, but only a navigable water of the
State”). It is this “junction” between waters to “for[m] a
continued highway for commerce, both with other States and
with foreign countries,” that brings the water “under the
direct control of Congress in the exercise of its commercial
power.” The Daniel Ball, 

. The defnition
of a “navigable water of the United States” was thus linked
directly to the limits on Congress' commerce authority: A
navigable water of the United States was one that was ordi-
narily used for interstate or foreign commerce.
   Wetlands were generally excluded from this defnition.
In Leovy v. United States, 

 (1900), for example,
the Court employed the Daniel Ball test to hold that the
term “navigable waters of the United States,” as used in the
1890 River and Harbor Act, did not “prevent the exercise by
the State of Louisiana of its power to reclaim swamp and
overfowed lands by regulating and controlling the current
                       Cite as: 

 (2023)                     695

                          Thomas, J., concurring

of small streams not used habitually as arteries of interstate
commerce.” 

. The Court observed that
applying the Act to wetlands reclamation “would extend the
paramount jurisdiction of the United States over all the
fowing waters in the States.” 

. “If such were
the necessary construction of the” term “navigable water,”
the Court explained, the River and Harbor Act's “validity
might well be questioned.” 

 But, the Court declined
to interpret the Act to reach the wetlands, because it recog-
nized that the phrase “navigable waters of the United
States” encompassed only those waters reached by the tradi-
tional channels-of-commerce authority:
     “When it is remembered that the source of the power of
     the general government to act at all in this matter arises
     out of its power to regulate commerce with foreign coun-
     tries and among the States, it is obvious that what the
     Constitution and the acts of Congress have in view is
Page Proof Pending Publication
     the promotion and protection of commerce in its interna-
     tional and interstate aspect, and a practical construction
     must be put on these enactments as intended for such
     large and important purposes.” 

The Court thus held that the mere use of a wetland by fsh-
ermen was not suffcient to make the wetland a navigable
water of the United States; it “was not shown that passen-
gers were ever carried through it, or that freight destined to
any other State than Louisiana, or, indeed, destined for any
market in Louisiana, was ever, much less habitually, carried
through it.” 

.4
  4
    Leovy v. United States also refected the law's longstanding hostility
to wetlands: “If there is any fact which may be supposed to be known by
everybody, and, therefore, by courts, it is that swamps and stagnant wa-
ters are the cause of malarial and malignant fevers, and that the police
power is never more legitimately exercised than in removing such nui-
sances.” 

. Traditionally, the only time wetlands were
the subject of federal legislation was to aid the States in draining them.
See, e. g., Swamp Land Act of 1850, ch. 84, 

; see also S. Johnson,
696                        SACKETT v. EPA

                         Thomas, J., concurring

   The Daniel Ball test, with minor variations, marked the
limits of federal jurisdiction over waters up to the enactment
of the CWA. For instance, in Economy Light & Power Co.
v. United States, 

 (1921), the Court applied The
Daniel Ball but expanded it to hold that the River and Har-
bor Act of 1899 reaches waters that are not currently capable
of supporting interstate commerce, though they once did.
256 U. S., at 123–124. And, in United States v. Appalachian
Elec. Power Co., 

 (1940), the Court applied The
Daniel Ball to reach waters that could be made navigable
with reasonable and feasible improvement. 311 U. S., at
408–409. While these cases expanded the outer boundaries
of the term, creating an expanded form of the Daniel Ball
test, they refect the Court's longstanding view that the stat-
utory term “navigable water” required application of the
Daniel Ball test.
                                2

Page       Proof Pending Publication
  In the New Deal era, as is well known, this Court adopted
a greatly expanded conception of Congress' commerce au-
thority by permitting Congress to regulate any private in-
trastate activity that substantially affects interstate com-
merce, either by itself or when aggregated with many similar
activities. See Wickard v. Filburn, 

, 127–129
(1942); see also United States v. Darby, 

(1941). Yet, this expansion did not fundamentally change
the Court's understanding that the term “navigable waters”
referred to waters used for interstate commerce. Thus, in
Appalachian Elec., the Court continued to apply the concept
of navigability to determine the scope of Congress' Com-
merce Clause authority to require licenses under the Federal
Water Power Act for the construction of hydroelectric dams
in “navigable waters.” 311 U. S., at 406–410. Only after
Wetlands Law: A Course Source 25–26 (2d ed. 2018). Wetlands preserva-
tion only gained traction due, in large part, to advances in frearms tech-
nology that made waterfowl hunting feasible. G. Baldassarre & E. Bolen,
Waterfowl Ecology and Management 10–14 (1994).
                   Cite as: 

 (2023)            697

                     Thomas, J., concurring

applying the Daniel Ball defnition to determine that the
river in question was navigable did the Court hold that Con-
gress had plenary authority over the erection of structures
in the river, regardless of whether the structure actually im-
peded navigability. 311 U. S., at 423–426. While this rep-
resented an expansive application of the old concept that
Congress can prevent obstructions to navigable capacity, see
supra, at 687, 690–691, Appalachian Elec. made clear that
the term “navigable waters” remained tethered to Congress'
traditional channels-of-commerce authority—not to the
broader conceptions of the commerce authority adopted by
the Court at that time.
   The next year, in Oklahoma ex rel. Phillips v. Guy F. At-
kinson Co., 

 (1941), the Court reaffrmed that
the term “navigable waters,” this time as used in the Flood
Control Act of 1936, was to be interpreted in light of the
expanded Daniel Ball test. 313 U. S., at 522–525. Signif-
Page Proof Pending Publication
cantly, Oklahoma was decided mere months after Darby, one
of the most signifcant cases expanding the scope of the com-
merce authority. 

. However, Oklahoma
did not so much as mention Darby in construing the jurisdic-
tion Congress conveyed in the term “navigable waters.” In-
stead, it cited Darby only in passing and to support the argu-
ment that, once a river is deemed navigable under the
channels-of-commerce authority, Congress has authority to
protect “the nation's arteries of commerce” by regulating in-
trastate activities on nonnavigable parts and tributaries of
the navigable river lest such activities “impai[r] navigation
itself.” Oklahoma, 

. This was nothing
more than an application of the principle that Congress can
regulate activities that obstruct navigable capacity. Thus,
even as the Court expanded the Commerce Clause in other
contexts, it continued to understand that the term “naviga-
ble waters” refers solely to the aquatic channels of interstate
commerce over which Congress traditionally exercised
authority.
698                    SACKETT v. EPA

                     Thomas, J., concurring

                               3
   This understanding of the term “navigable waters”—i. e.,
as shorthand for waters subject to Congress' authority under
the Daniel Ball test—persisted up to the enactment of the
CWA. See, e. g., Stoeco Homes, Inc., 498 F. 2d, at 608–609;
United States v. Joseph G. Moretti, Inc., 

, 428–
429 (CA5 1973); see also D. Guinn, An Analysis of Navigable
Waters of the United States, 

, 579
(1966) (“[T]he test of The Daniel Ball and Appalachian
Power Co. are religiously cited as being the basis for the
holding on the issue of navigability”). As a court observed
near the time of the CWA's enactment, “[a]lthough the def-
nition of `navigability' laid down in The Daniel Ball has sub-
sequently been modifed and clarifed, its defnition of `navi-
gable water of the United States,' insofar as it requires a
navigable interstate linkage by water, appears to remain un-
changed.” Hardy Salt Co. v. Southern Pacifc Transp. Co.,
Page Proof Pending Publication

, 1167 (CA10 1974) (citations omitted). This
Court's cases, too, continued to apply traditional navigability
concepts in cases under the River and Harbor Acts right up
to the CWA's enactment. See United States v. Standard Oil
Co., 

 (1966) (holding that spilling oil in a
navigable water was prohibited by the Refuse Act (§ 13 of
the 1899 Act) because “its presence in our rivers and harbors
is both a menace to navigation and a pollutant”); United
States v. Republic Steel Corp., 

, 487–491 (1960)
(“diminution of the navigable capacity of a waterway” re-
quired for violation of the Refuse Act). Thus, on the eve of
the CWA's enactment, the term “navigable waters” meant
those waters that are, were, or could be used as highways of
interstate or foreign commerce.

                              II
  This history demonstrates that Congress was not writing
on a blank slate in the CWA, which defnes federal jurisdic-
                        Cite as: 

 (2023)                      699

                           Thomas, J., concurring

tion using the same terms used in the River and Harbor
Acts: “navigable waters” and “ the waters of the United
States,” 

(a), 1362(7), (12). As explained
above, courts and Congress had long used the terms “naviga-
ble water,” “navigable water of the United States,” and “the
waters of the United States” interchangeably to signify those
waters to which the traditional channels-of-commerce au-
thority extended. See supra, at 689. The terms “naviga-
ble waters” and “waters of the United States” shared a core
requirement that the water be a “highway over which com-
merce is or may be carried,” with the term “of the United
States” doing the independent work of requiring that such
commerce “be carried on with other States or foreign coun-
tries.” The Daniel Ball, 

. The text of the
CWA thus refects the traditional balance between federal
and state authority over navigable waters, as set out by The
Daniel Ball. It would be strange indeed if Congress sought
Page Proof Pending Publication
to effect a fundamental transformation of federal jurisdiction
over water through phrases that had been in use to describe
the traditional scope of that jurisdiction for well over a cen-
tury and that carried a well-understood meaning.5
   The Army Corps of Engineers originally understood the
CWA in precisely this way. In its 1974 regulation establish-

  5
    In fact, when Congress has wished to depart from this traditional
meaning, it has done so expressly, as in parts of the Federal Power Act,
§ 23, 

 (requiring approval for dam construction “across, along,
over, or in any stream or part thereof, other than those defned herein this
chapter as navigable waters”); the Federal Water Pollution Control Act,
ch. 758, § 2(a), 

 (as amended, 

) (authorizing federal-
state cooperation to abate water pollution in “interstate waters” and their
tributaries); and the Water Quality Act of 1965, 79 Stat. 905–906 (authoriz-
ing grants to research abatement of pollution into “any waters”); see
Hardy Salt Co. v. Southern Pacifc Transp. Co., 

, 1168 (CA10
1974) (noting that Congress only departs from the expanded Daniel Ball
test by using “clear and explicit language,” as it did in parts of the Federal
Power Act).
700                          SACKETT v. EPA

                          Thomas, J., concurring

ing the frst CWA § 404 permitting program,6 the Corps in-
terpreted the term “the waters of the United States” to es-
tablish jurisdiction over the traditional navigable waters as
determined by the expanded Daniel Ball test, noting also
that the term is limited by Congress' navigation authority.

. The Corps anchored its jurisdiction in
the expanded Daniel Ball test, defning “navigable waters”
to include “those waters of the United States which are sub-
ject to the ebb and fow 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.” 

(d)(1) (1974); see also §§ 209.260(d)(1)–(3) (re-
quiring “[p]ast, present, or potential presence of interstate
or foreign commerce,” “[p]hysical capabilities for use by com-
merce,” and “[d]efned geographic limits of the water body”).
The regulations also made clear that traditional navigability
factors were the baseline for CWA jurisdiction: “It is the
water body's capability of use by the public for purposes
Page Proof Pending Publication
of transportation or commerce which is the determinative
factor.” § 209.260(e)(1).
   Almost immediately, however, a few courts and the re-
cently created Environmental Protection Agency (EPA) re-
jected this interpretation. Instead, they interpreted the
CWA to assert the full extent of Congress' New Deal era
authority to regulate anything that substantially affects in-
terstate commerce by itself or in the aggregate. See United
States v. Ashland Oil & Transp. Co., 

, 1323–
1329 (CA6 1974); P. F. Z. Properties, Inc. v. Train, 

 (DC 1975); National Resources Defense
Council, Inc. v. Callaway, 

 (DC 1975);
United States v. Holland, 

, 672–674 (MD
Fla. 1974); 

(o) (1974) (initial EPA CWA defni-
tion). The courts that reached this conclusion relied almost
exclusively on legislative history and statutory purpose.
  6
    Section 404 authorizes the Corps to “issue permits . . . for the discharge
of dredged or fll material into the navigable waters at specifed disposal
sites.” 

(a), (d).
                    Cite as: 

 (2023)             701

                      Thomas, J., concurring

See, e. g., Holland, 

 (“The foregoing [leg-
islative history] compels the Court to conclude that the for-
mer test of navigability was indeed defned away in the
[CWA]”). But signals from legislative history cannot rebut
clear statutory text, and the text of the CWA employs words
that had long been universally understood to reach only
those waters subject to Congress' channels-of-commerce au-
thority. See supra, at 698.
   These courts and the EPA had only one textual hook for
their interpretation: In defning the term “navigable waters”
as “the waters of the United States,” the CWA seemed to
drop the term “navigable” from the operative part of the
definition. Seizing on this phrasing, the EPA's general
counsel asserted in 1973 that “the deletion of the word `navi-
gable' eliminates the requirement of navigability. The only
remaining requirement, then, is that pollution of waters cov-
ered by the bill must be capable of affecting interstate com-
merce.” 1 EPA Gen. Counsel Op. 295 (1973). Similarly, the
Page Proof Pending Publication
District Court that vacated the Corps' original CWA defni-
tion held, without any analysis or citation, that the term “the
waters of the United States” in the CWA is “not limited to
the traditional tests of navigability.” National Resources
Defense Council, 

.
   That interpretation cannot be right. For one, the terms
“navigable waters” and “the waters of the United States”
had long been used synonymously by courts and Congress.
The CWA simply used the terms in the same manner as the
River and Harbor Acts. Moreover, no source prior to the
CWA had ever asserted that the term “the waters of the
United States,” when not modifed by “navigable,” reached
any water that may affect interstate commerce. Instead,
The Daniel Ball made clear that “[t]he phrase `waters of the
United States, . . . in contradistinction from the navigable
waters of the States,' . . . distinguishes interstate from intra-
state waters.” Albrecht & Nickelsburg 11049 (quoting The
Daniel Ball, 

); accord, 1 A. Knauth, Benedict
on Admiralty § 44, p. 96 (6th ed. 1940) (“The inland lakes of
702                        SACKETT v. EPA

                         Thomas, J., concurring

various States are navigable but, having no navigable outlet
linking them with our system of water-ways, have never
been held to be public waters of the United States” (emphasis
added)). The text of the CWA extends jurisdiction to “navi-
gable waters,” and—precisely tracking The Daniel Ball—
clarifes that it reaches “the waters of the United States,”
rather than the navigable waters of the States.
   Thus, the CWA's use of the phrase “the waters of the
United States” reinforces, rather than lessens, the need for
a water to be at least part of “a continued highway over
which commerce is or may be carried on with other States
or foreign countries in the customary modes in which such
commerce is conducted by water.” The Daniel Ball, 

. At most, the omission of the word “navigable”
signifes that the CWA adopts the expanded Daniel Ball
test—that includes waters that are, have been, or can be rea-
sonably made navigable in fact—in its statutory provisions.
Page Proof Pending Publication
The Federal Government's interpretation, by contrast, ren-
ders the use of the term “navigable” a nullity and involves
an unprecedented and extravagant reading of the well-
understood term of art “the waters of the United States.”
See Albrecht & Nickelsburg 11049 (“EPA's conclusion is ahis-
torical as well as illogical”).7 “[T]he waters of the United
States” does not mean any water in the United States.

  7
    To be sure, the CWA is more aggressive in regulating navigable waters
than the River and Harbor Acts. But, the increased stringency is not
accomplished by expanding jurisdiction. The Acts use the same jurisdic-
tional terms. Instead, the difference between them lies in the expanded
scope of activities that the CWA regulates and its shift from an enforce-
ment and injunctive regime to a previolation licensing regime. See Al-
brecht & Nickelsburg 11046. I express no view on the constitutionality
of this regime as applied to navigable waters or on the Court's holding in
United States v. Appalachian Elec. Power Co., 

 (1940), that
Congress can regulate things in navigable waters for purposes other than
removing obstructions to navigable capacity. I note, however, that before
the New Deal era, courts consistently construed statutes to authorize only
federal actions preserving navigable capacity in order to avoid exceeding
Congress' navigation authority. See supra, at 691–696.
                       Cite as: 

 (2023)                   703

                         Thomas, J., concurring

   There would be little need to explain any of this if the
agencies had not effectively flouted our decision in
SWANCC, which restored navigability as the touchstone of
federal jurisdiction under the CWA, and rejected the key
arguments supporting an expansive interpretation of the
CWA's text. We expressly held that Congress' “use of the
phrase `waters of the United States' ” in the CWA is not “a
basis for reading the term `navigable waters' out of the stat-
ute”—directly contradicting the EPA's 1973 interpretation,
upon which every subsequent expansion of its authority has
been based. 531 U. S., at 172. We also held that the Corps
did not “mist[ake] Congress' intent” when it promulgated its
1974 regulations, under which “ `the determinative factor' ”
for navigability was a “ `water body's capability of use by the
public for purposes of transportation or commerce.' ” Id.,
at 168 (quoting 

(e)(1)). In doing so, we re-
jected reliance on the CWA's “ambiguous” legislative history,
which the EPA had used “to expand the defnition of `naviga-
Page Proof Pending Publication
ble waters' ” to the outer limit of the commerce authority as
interpreted in the New Deal. 531 U. S., at 168, n. 3.8 In-
stead, we made clear that Congress did not intend “to exert
anything more than its commerce power over navigation.”
Ibid.; see also id., at 173 (rejecting the Government's ar-
gument that the CWA invokes “Congress' power to regu-
late intrastate activities that `substantially affect' interstate
commerce”).
   SWANCC thus interpreted the text of the CWA as imple-
menting Congress' “traditional jurisdiction over waters that
  8
    The historical context demonstrates that it was the Corps' failure to
regulate to the full extent of Congress' navigation power, not its commerce
power generally, that led to the enactment of the CWA. See Albrecht &
Nickelsburg 11047 (explaining that the CWA's legislative history is better
interpreted “as the Supreme Court in SWANCC read it, to mean simply
that Congress intended to override previous, unduly narrow agency inter-
pretations to assert its broadest constitutional authority over the tradi-
tional navigable waters”); see also S. Bodine, Examining the Term “Wa-
ters of the United States” in Its Historical Context, C. Boyden Gray
Center for the Study of the Administrative State Policy Brief No. 4 (2022).
704                          SACKETT v. EPA

                          Thomas, J., concurring

were or had been navigable in fact or which could reason-
ably be so made”—i. e., the expanded Daniel Ball test. 531
U. S., at 172 (citing Appalachian Elec., 311 U. S., at 407–
408).9 And, consistent with the traditional link between
navigability and the limits of Congress' regulatory authority,
SWANCC noted that any broader interpretation would raise
“signifcant constitutional and federalism questions” and “re-
sult in a signifcant impingement of the States' traditional
and primary power over land and water use.” 531 U. S., at
174. Both in its holdings and in its mode of analysis,
SWANCC cannot be reconciled with the agencies' sharp
departure from the centuries-old understanding of naviga-

  9
    Section 404(g), added by the 1977 CWA Amendments, does not demon-
strate that the CWA departs from traditional conceptions of navigability.
That provision states that States may administer permit programs for
discharges into “navigable waters (other than those waters which are pres-
ently used, or are susceptible to use in their natural condition or by reason-
Page Proof Pending Publication
able improvement as a means to transport interstate or foreign commerce
. . . , including wetlands adjacent thereto).” 

 (codifed, as
amended, at 

(g)). This provision thus authorizes States
to establish their own permit programs over a discrete class of tradition-
ally navigable waters of the United States: those that once were navigable
waters of the United States, but are no longer navigable in fact. See
Economy Light & Power Co., 256 U. S., at 123–124. Some have asserted
that this nonjurisdictional provision—the function of which in the statute
is to expand state authority—signals that Congress actually intended an
unprecedented expansion of federal authority over the States. Rapanos
v. United States, 

, 805–806 (2006) (Stevens, J., dissenting); see
also post, at 717–719 (Kavanaugh, J., concurring in judgment); post, at
710–712 (Kagan, J., concurring in judgment). But, as the Court explains,
not only is § 404(g) not the relevant defnitional provision, its reference to
“wetlands” is perfectly consistent with the commonsense recognition that
some wetlands are indistinguishable from navigable waters with which
they have continuous surface connections. Ante, at 674–679, 683–684.
To infer Congress' intent to upend over a century of settled understanding
and effect an unprecedented transfer of authority over land and water to
the Federal Government, based on nothing more than a negative inference
from a parenthetical in a subsection that preserves state authority, is coun-
terintuitive to say the least.
                   Cite as: 

 (2023)            705

                     Thomas, J., concurring

bility and the traditional limits of Congress' channels-of-
commerce authority.
   In sum, the plain text of the CWA and our opinion in
SWANCC demonstrate that the CWA must be interpreted
in light of Congress' traditional authority over navigable
waters. See Albrecht & Nickelsburg 11055 (noting that
SWANCC “states more than once that Congress' use of the
term `navigable waters' signifes that Congress intended to
exercise its traditional authority over navigable waters, and
not its broader power over all things that substantially affect
commerce”). Yet, for decades, the EPA (of its own license)
and the Corps (under the compulsion of an unreasoned and
since discredited District Court order) have issued substan-
tively identical regulatory defnitions of “the waters of the
United States” that completely ignore navigability and in-
stead expand the CWA's coverage to the outer limits of the
Court's New Deal-era Commerce Clause precedents.

Page Proof Pending
             III   Publication
   This case demonstrates the unbounded breadth of the ju-
risdiction that the EPA and the Corps have asserted under
the CWA. The regulatory defnition applied to the Sacketts'
property declares “intrastate” waters, wetlands, and various
other wet things to be “waters of the United States” if their
“use, degradation or destruction . . . could affect interstate
or foreign commerce.” 

(s)(3) (2008) (empha-
sis added). To leave no doubt that the agencies have en-
tirely broken from traditional navigable waters, they give
several examples of qualifying waters: those that “are or
could be used by interstate or foreign travelers for recre-
ational or other purposes,” those “[f]rom which fsh or shell-
fsh are or could be taken and sold in interstate or foreign
commerce,” those that “are used or could be used for indus-
trial purposes by industries in interstate commerce,” “[t]rib-
utaries of ” any such waters, and “[w]etlands adjacent to” any
such waters. §§ 230.3(s)(3)(i)–(iii), (5), (7). This defnition
706                    SACKETT v. EPA

                     Thomas, J., concurring

and others like it are premised on the fallacy repudiated in
SWANCC: that the text of the CWA expands federal juris-
diction beyond Congress' traditional “commerce power over
navigation.” 531 U. S., at 168, n. 3.
   Nonetheless, under these boundless standards, the agen-
cies have “asserted jurisdiction over virtually any parcel of
land containing a channel or conduit . . . through which rain-
water or drainage may occasionally or intermittently fow,”
including “storm drains, roadside ditches, ripples of sand in
the desert that may contain water once a year, and lands
that are covered by floodwaters once every 100 years.”
Rapanos, 

 (plurality opinion). The agencies'
defnition “engulf[s] entire cities and immense arid waste-
lands” alike. 

 Indeed, because “the entire land area of
the United States lies in some drainage basin, and an endless
network of visible channels furrows the entire surface,”
“[a]ny plot of land containing such a channel may potentially
Page Proof Pending Publication
be regulated.” 

   If this interpretation were correct, the only prudent move
for any landowner in America would be to ask the Federal
Government for permission before undertaking any kind of
development. See Tr. of Oral Arg. 86, 116–117. This re-
gime turns Congress' traditionally limited navigation au-
thority on its head. The baseline under the Constitution,
the CWA, and the Court's precedents is state control of
waters. See SWANCC, 531 U. S., at 174 (reaffrming “the
States' traditional and primary power over land and water
use”); Leovy, 

 (repudiating an interpretation
of the 1899 Act that would render practically every “creek
or stream in the entire country” a “navigable water of the
United States” and “subject the offcers and agents of a State
. . . to fne and imprisonment” for draining a swamp “unless
permission [was] frst obtained from the Secretary of War”).
By contrast, the agencies' interpretation amounts to a fed-
eral police power, exercised in the most aggressive possi-
ble way.
                  Cite as: 

 (2023)           707

                     Thomas, J., concurring

   Thankfully, applying well-established navigability rules
makes this a straightforward case. The “wetlands” on the
Sacketts' property are not “waters of the United States” for
several independently suffcient reasons. First, for the rea-
sons set out by the Court, the Sacketts' wetlands are not
“waters” because they lack a continuous surface connection
with a traditional navigable water. See ante, at 684. Sec-
ond, the nonnavigable so-called “tributary” (really, a road-
side ditch) across the street from the Sacketts' property is
not a water of the United States because it is not, has never
been, and cannot reasonably be made a highway of interstate
or foreign commerce. See SWANCC, 531 U. S., at 172.
Third, the agencies have not attempted to establish that
Priest Lake is a navigable water under the expanded Daniel
Ball test. The lake is purely intrastate, and the agencies
have not shown that it is a highway of interstate or foreign
commerce. Instead, the agencies rely primarily upon inter-
Page Proof Pending Publication
state tourism and the lake's attenuated connection to naviga-
ble waters. See U. S. Army Corps of Engineers, G. Rayner,
Priest Lake Jurisdictional Determination (Feb. 27, 2007); see
also Brief for National Association of Home Builders of the
United States as Amicus Curiae 21–24. But, this is likely
insuffcient under the traditional navigability tests to which
the CWA pegs jurisdiction. See supra, at 693–696; accord,
Tr. of Oral Arg. 119 (EPA counsel conceding that Congress
“hasn't used its full Commerce Clause authority” in the
CWA). Finally, even assuming that a navigable water is in-
volved, the agencies have not established that the Sacketts'
actions would obstruct or otherwise impede navigable capac-
ity or the suitability of the water for interstate commerce.
See Rio Grande Dam & Irrigation Co., 

.
   This is not to say that determining whether a water quali-
fes under the CWA is always easy. But, it is vital that we
ask the right question in determining what constitutes “the
waters of the United States”: whether the water is within
Congress' traditional authority over the interstate channels
708                         SACKETT v. EPA

                          Thomas, J., concurring

of commerce. Here, no elaborate analysis is required to
know that the Sacketts' land is not a water, much less a
water of the United States.
                                    IV
   What happened to the CWA is indicative of deeper prob-
lems with the Court's Commerce Clause jurisprudence. The
eclipse of Congress' well-defned authority over the channels
of interstate commerce tracks the Court's expansion of Con-
gress' power “[t]o regulate Commerce with foreign Nations,
and among the several States, and with the Indian Tribes.”
Art. I, § 8, cl. 3. As I have explained at length, the Court's
Commerce Clause jurisprudence has signifcantly departed
from the original meaning of the Constitution. See Gonza-
les v. Raich, 

, 58–59 (2005) (dissenting opinion);
Lopez, 514 U. S., at 586–602 (concurring opinion). “The
Clause's text, structure, and history all indicate that, at the
time of the founding, the term ` “commerce” consisted of sell-
Page Proof Pending Publication
ing, buying, and bartering, as well as transporting for these
purposes.' ” Raich, 

. This meaning “stood
in contrast to productive activities like manufacturing and
agriculture,” and founding era sources demonstrate that “the
term `commerce' [was] consistently used to mean trade or
exchange—not all economic or gainful activity that has some
attenuated connection to trade or exchange.” 

 (citing
Lopez, 514 U. S., at 586–587 (Thomas, J., concurring); Bar-
nett 112–125).10 By departing from this limited mean-
   10
      Further scholarship notes that the term “commerce” as originally un-
derstood “was bound tightly with the Lex Mercatoria and the sort of ac-
tivities engaged in by merchants: buying and selling products made by
others (and sometimes land), associated fnance and fnancial instruments,
navigation and other carriage, and intercourse across jurisdictional lines.”
R. Natelson, The Legal Meaning of “Commerce” in the Commerce Clause,

, 845 (2006). This “did not include agriculture,
manufacturing, mining, malum in se crime, or land use. Nor did it in-
clude activities that merely `substantially affected' commerce; on the con-
                      Cite as: 

 (2023)                   709

                         Thomas, J., concurring

ing, the Court's cases have licensed federal regulatory
schemes that would have been “unthinkable” to the Constitu-
tion's Framers and ratifers. Raich, 

 (opinion
of Thomas, J.).
   Perhaps nowhere is this deviation more evident than in
federal environmental law, much of which is uniquely de-
pendent upon an expansive interpretation of the Commerce
Clause. See Hodel v. Virginia Surface Mining & Reclama-
tion Assn., Inc., 

, 281–283 (1981); see also Brief
for Claremont Institute's Center for Constitutional Jurispru-
dence as Amicus Curiae 17–25. And many environmental
regulatory schemes seem to push even the limits of the
Court's New Deal-era Commerce Clause precedents, see
Hodel, 452 U. S., at 309–313 (Rehnquist, J., concurring in
judgment), to say nothing of the Court's more recent prece-
dents reining in the commerce power. See, e. g., SWANCC,
531 U. S., at 173–174; cf. Rancho Viejo, LLC v. Norton, 

, 1160 (CADC 2003) (per curiam) (Roberts, J., dis-
Page Proof Pending Publication
senting from denial of rehearing en banc) (“The panel's ap-
proach in this case leads to the result that regulating the
taking [under the Endangered Species Act] of a hapless toad
that, for reasons of its own, lives its entire life in California
constitutes regulating `Commerce among the several
States' ” (ellipsis omitted)).
   The Court's opinion today curbs a serious expansion of fed-
eral authority that has simultaneously degraded States' au-
thority and diverted the Federal Government from its im-
portant role as guarantor of the Nation's great commercial
water highways into something resembling “a local zon-
ing board.” Rapanos, 

 (plurality opinion).
But, wetlands are just the beginning of the problems raised
by the agencies' assertion of jurisdiction in this case. De-
spite our clear guidance in SWANCC that the CWA extends
trary, the cases include wording explicitly distinguishing such activities
from commerce.” 

710                    SACKETT v. EPA

                Kagan, J., concurring in judgment

only to the limits of Congress' traditional jurisdiction over
navigable waters, the EPA and the Corps have continued to
treat the statute as if it were based on New Deal era concep-
tions of Congress' commerce power. But, while not all envi-
ronmental statutes are so textually limited, Congress chose
to tether federal jurisdiction under the CWA to its tradi-
tional authority over navigable waters. The EPA and the
Corps must respect that decision.

  Justice Kagan, with whom Justice Sotomayor and
Justice Jackson join, concurring in the judgment.
   Like Justice Kavanaugh, “I would stick to the text.”
Post, at 727 (opinion concurring in judgment). As he ex-
plains in the principal concurrence, our normal method of
construing statutes identifes which wetlands the Clean
Water Act covers—and the answer provided exceeds what
the Court says today. Because the Act covers “the waters
Page Proof Pending Publication
of the United States,” and those waters “includ[e]” all wet-
lands “adjacent” to other covered waters, the Act extends to
those “adjacent” wetlands. 

(7), 1344(g)(1).
And in ordinary language, one thing is adjacent to another
not only when it is touching, but also when it is nearby. See
post, at 718–720 (quoting multiple dictionaries). So, for ex-
ample, one house is adjacent to another even when a stretch
of grass and a picket fence separate the two. As applied
here, that means—as the EPA and Army Corps have recog-
nized for almost half a century—that a wetland comes within
the Act if (i) it is “contiguous to or bordering a covered
water, or (ii) if [it] is separated from a covered water only
by a man-made dike or barrier, natural river berm, beach
dune, or the like.” Post, at 728 (emphasis in original). In
excluding all the wetlands in category (ii), the majority's
“ `continuous surface connection' test disregards the ordinary
meaning of `adjacent.' ” Post, at 722. The majority thus al-
ters—more precisely, narrows the scope of—the statute Con-
gress drafted.
                   Cite as: 

 (2023)           711

                Kagan, J., concurring in judgment

   And make no mistake: Congress wrote the statute it meant
to. The Clean Water Act was a landmark piece of environ-
mental legislation, designed to address a problem of “crisis
proportions.” R. Adler, J. Landman, & D. Cameron, The
Clean Water Act: 20 Years Later 5 (1993). How bad was
water pollution in 1972, when the Act passed? Just a few
years earlier, Ohio's Cuyahoga River had “burst into fames,
fueled by oil and other industrial wastes.” 

 And that
was merely one of many alarms. Rivers, lakes, and creeks
across the country were unft for swimming. Drinking
water was full of hazardous chemicals. Fish were dying in
record numbers (over 40 million in 1969); and those caught
were often too contaminated to eat (with mercury and DDT
far above safe levels). See 

 at 5–6. So Congress em-
barked on what this Court once understood as a “total
restructuring and complete rewriting” of existing water
pollution law. Milwaukee v. Illinois, 

, 317
Page Proof Pending Publication
(1981) (internal quotation marks omitted). The new Act
established “a self-consciously comprehensive” and “all-
encompassing program of water pollution regulation.” 

at 318–319. Or said a bit differently, the Act created a
program broad enough to achieve the codifed objective of
“restor[ing] and maintain[ing] the chemical, physical, and
biological integrity of the Nation's waters.” § 1251(a). If
you've lately swum in a lake, happily drunk a glass of water
straight from the tap, or sat down to a good fsh dinner, you
can appreciate what the law has accomplished.
   Vital to the Clean Water Act's project is the protection of
wetlands—both those contiguous to covered waters and oth-
ers nearby. As this Court (again, formerly) recognized,
wetlands “serve to flter and purify water draining into ad-
jacent bodies of water, and to slow the fow of surface run-
off into lakes, rivers, and streams.” United States v. River-
side Bayview Homes, Inc., 

 (1985) (citation
omitted). Wetlands thus “function as integral parts of the
aquatic environment”—protecting neighboring water if
712                    SACKETT v. EPA

                Kagan, J., concurring in judgment

themselves healthy, imperiling neighboring water if instead
degraded. 

. At the same time, wetlands play a
crucial part in food control (if anything, more needed now
than when the statute was enacted). And wetlands perform
those functions, as Justice Kavanaugh explains, not only
when they are touching a covered water but also when they
are separated from it by a natural or artifcial barrier—say, a
berm or dune or dike or levee. See post, at 725–727 (giving
examples). Those barriers, as he says, “do not block
all water fow,” and in fact are usually evidence of a signif-
cant connection between the wetland and the water. 

Small wonder, then, that the Act—as written, rather than as
read today—covers wetlands with that kind of connection.
Congress chose just the word needed to meet the Act's objec-
tive. A wetland is protected when it is “adjacent” to a cov-
ered water—not merely when it is “adjoining” or “contigu-
ous” or “touching,” or (in the majority's favorite made-up
Page Proof Pending Publication
locution) has a “continuous surface connection.” See, e. g.,
ante, at 684.
   Today's majority, though, believes Congress went too far.
In the majority's view, the Act imposes unjustifably “crush-
ing consequences” for violations of its terms. Ante, at 660.
And many of those violations, it thinks, are of no real con-
cern, arising from “mundane” land-use conduct “like moving
dirt.” Ante, at 669. Congress, the majority scolds, has
unleashed the EPA to regulate “swimming pools[ ] and
puddles,” wreaking untold havoc on “a staggering array of
landowners.” Ante, at 659, 670. Surely something has to
be done; and who else to do it but this Court? It must res-
cue property owners from Congress's too-ambitious program
of pollution control.
   So the majority shelves the usual rules of interpretation—
reading the text, determining what the words used there
mean, and applying that ordinary understanding even if it
conficts with judges' policy preferences. The majority's
frst pass through the statute is, as Justice Kavanaugh
                   Cite as: 

 (2023)            713

                Kagan, J., concurring in judgment

says, “unorthodox.” Post, at 723. “A minus B, which in-
cludes C”? Ante, at 675. The majority could use every let-
ter of the alphabet, and graduate to quadratic equations, and
still not solve its essential problem. As the majority con-
cedes, the statute “tells us that at least some wetlands must
qualify as `waters of the United States.' ” 

 More, the
statute tells us what those “some wetlands” are: the “adja-
cent” ones. And again, as Justice Kavanaugh shows, “ad-
jacent” does not mean adjoining. See post, at 718–720;
supra, at 710. So the majority proceeds to its back-up plan.
It relies as well on a judicially manufactured clear-statement
rule. When Congress (so says the majority) exercises
power “over private property”—particularly, over “land and
water use”—it must adopt “exceedingly clear language.”
Ante, at 679 (internal quotation marks omitted). There is,
in other words, a thumb on the scale for property owners—
no matter that the Act (i. e., the one Congress enacted) is all
Page Proof Pending Publication
about stopping property owners from polluting. See supra,
at 711.
   Even assuming that thumb's existence, the majority still
would be wrong. As Justice Kavanaugh notes, clear-
statement rules operate (when they operate) to resolve prob-
lems of ambiguity and vagueness. See post, at 725; see also
Bond v. United States, 

 (2014); United
States v. Bass, 

 (1971). And no such prob-
lems are evident here. One last time: “Adjacent” means
neighboring, whether or not touching; so, for example, a wet-
land is adjacent to water on the other side of a sand dune.
That congressional judgment is as clear as clear can be—
which is to say, as clear as language gets. And so a clear-
statement rule must leave it alone. The majority concludes
otherwise because it is using its thumb not to resolve ambi-
guity or clarify vagueness, but instead to “correct” breadth.
Those paying attention have seen this move before—actu-
ally, just last Term. In another case of environmental regu-
lation (involving clean air), the Court invoked another clear-
714                    SACKETT v. EPA

                Kagan, J., concurring in judgment

statement rule (the so-called major questions doctrine) to
diminish another plainly expansive term (“system of emis-
sion reduction”). See West Virginia v. EPA, 597 U. S.
–––, –––, ––– (2022). “[C]ontra the majority,” I said then, “a
broad term is not the same thing as a `vague' one.” 

 at –––
(dissenting opinion). And a court must treat the two differ-
ently. A court may, on occasion, apply a clear-statement rule
to deal with statutory vagueness or ambiguity. But a court
may not rewrite Congress's plain instructions because they
go further than preferred. That is what the majority does
today in fnding that the Clean Water Act excludes many
wetlands (clearly) “adjacent” to covered waters.
   And still more fundamentally, why ever have a thumb on
the scale against the Clean Water Act's protections? The
majority frst invokes federalism. See ante, at 679–680.
But as Justice Kavanaugh observes, “the Federal Govern-
ment has long regulated the waters of the United States,
Page Proof Pending Publication
including adjacent wetlands.” Post, at 725. The majority
next raises the specter of criminal penalties for “indetermi-
nate” conduct. See ante, at 680–681. But there is no pecu-
liar indeterminacy in saying—as regulators have said for
nearly a half century—that a wetland is covered both when
it touches a covered water and when it is separated by only
a dike, berm, dune, or similar barrier. (That standard is in
fact more defnite than a host of criminal laws I could name.)
Today's pop-up clear-statement rule is explicable only as a
refexive response to Congress's enactment of an ambitious
scheme of environmental regulation. It is an effort to cabin
the anti-pollution actions Congress thought appropriate.
See ante, at 680 (complaining about Congress's protection of
“vast” and “staggering” “additional area”). And that, too,
recalls last Term, when I remarked on special canons “magi-
cally appearing as get-out-of-text-free cards” to stop the
EPA from taking the measures Congress told it to. See
West Virginia, 597 U. S., at ––– – ––– (dissenting opinion).
There, the majority's non-textualism barred the EPA from
                   Cite as: 

 (2023)            715

              Kavanaugh, J., concurring in judgment

addressing climate change by curbing power plant emissions
in the most effective way. Here, that method prevents the
EPA from keeping our country's waters clean by regulating
adjacent wetlands. The vice in both instances is the same:
the Court's appointment of itself as the national decision-
maker on environmental policy.
  So I'll conclude, sadly, by repeating what I wrote last year,
with the replacement of only a single word. “[T]he Court
substitutes its own ideas about policymaking for Congress's.
The Court will not allow the Clean [Water] Act to work as
Congress instructed. The Court, rather than Congress, will
decide how much regulation is too much.” 

 at –––.
Because that is not how I think our Government should
work—more, because it is not how the Constitution thinks
our Government should work—I respectfully concur in the
judgment only.

  Justice Kavanaugh, with whom Justice Sotomayor,
Page     Proof
Justice Kagan,     Pending
               and Justice JacksonPublication
                                   join, concurring in
the judgment.
  The Clean Water Act generally prohibits dumping dredged
or fll material without a permit into the “waters of the
United States.” 

(a), 1344(a), 1362. The
“waters of the United States” include wetlands that are “ad-
jacent” to waters covered by the Act—for example, wetlands
that are adjacent to covered rivers or lakes. §§ 1344(g),
1362(7). The question in this case is whether the wetlands
on the Sacketts' residential property are adjacent to covered
waters and therefore covered under the Act.
  The Ninth Circuit held that the wetlands on the Sacketts'
property are covered by the Clean Water Act because, as
relevant here, the wetlands have a “signifcant nexus” to cov-
ered waters nearby. 

, 1093 (2021). The Court
today reverses the Ninth Circuit's judgment.
  I agree with the Court's reversal of the Ninth Circuit. In
particular, I agree with the Court's decision not to adopt the
716                    SACKETT v. EPA

              Kavanaugh, J., concurring in judgment

“signifcant nexus” test for determining whether a wetland
is covered under the Act. And I agree with the Court's
bottom-line judgment that the wetlands on the Sacketts'
property are not covered by the Act and are therefore not
subject to permitting requirements.
   I write separately because I respectfully disagree with the
Court's new test for assessing when wetlands are covered by
the Clean Water Act. The Court concludes that wetlands
are covered by the Act only when the wetlands have a “con-
tinuous surface connection” to waters of the United States—
that is, when the wetlands are “adjoining” covered waters.
Ante, at 671, 684 (internal quotation marks omitted). In my
view, the Court's “continuous surface connection” test de-
parts from the statutory text, from 45 years of consistent
agency practice, and from this Court's precedents. The
Court's test narrows the Clean Water Act's coverage of “ad-
jacent” wetlands to mean only “adjoining” wetlands. But
“adjacent” and “adjoining” have distinct meanings: Adjoin-
Page Proof Pending Publication
ing wetlands are contiguous to or bordering a covered water,
whereas adjacent wetlands include both (i) those wetlands
contiguous to or bordering a covered water, and (ii) wetlands
separated from a covered water only by a man-made dike
or barrier, natural river berm, beach dune, or the like. By
narrowing the Act's coverage of wetlands to only adjoin-
ing wetlands, the Court's new test will leave some long-
regulated adjacent wetlands no longer covered by the Clean
Water Act, with signifcant repercussions for water quality
and food control throughout the United States. Therefore,
I respectfully concur only in the Court's judgment.

                               I
  The Clean Water Act generally prohibits dumping a “pol-
lutant”—including dredged or fll material—into “navigable
waters” without a permit. 

(a), 1344(a),
1362. The Act defnes “navigable waters” as “the waters of
the United States, including the territorial seas.” § 1362(7).
                   Cite as: 

 (2023)           717

              Kavanaugh, J., concurring in judgment

   As the Court today ultimately agrees, see ante, at 676, and
the Sacketts acknowledge, see Tr. of Oral Arg. 7–8, 33–34,
56–57, the statutory term “waters of the United States” cov-
ers wetlands “adjacent” to waters of the United States—for
example, wetlands adjacent to a river or lake that is itself a
water of the United States. 

(g).
   As enacted in 1972, the Clean Water Act protected “the
waters of the United States.” §§ 1311(a), 1362(7), 1362(12).
In 1975, the Army Corps interpreted “waters of the United
States” to include wetlands “adjacent to other navigable wa-
ters.” 

. In 1977, Congress expressly
adopted that same understanding of the Act, amending the
Act to make clear that only the Federal Government, and not
the States, may issue Clean Water Act permits for dumping
dredged or fll material into certain “waters of the United
States,” “including wetlands adjacent” to those covered wa-
ters. Clean Water Act, 

; 

(g).
Page Proof Pending Publication
In that 1977 Act, Congress thus expressly recognized “adja-
cent wetlands” as “waters of the United States.”
   Interpreting the text of the Act as amended in 1977, this
Court has long held that the Act covers “adjacent” wetlands.
See United States v. Riverside Bayview Homes, Inc., 

, 134–135, 138 (1985) (“Congress expressly stated
that the term `waters' included adjacent wetlands”); see also
Rapanos v. United States, 

 (2006) (plural-
ity opinion) (wetlands that “are `adjacent to' ” waters of the
United States are “covered by the Act”); Solid Waste Agency
of Northern Cook Cty. v. Army Corps of Engineers, 

 (2001) (recognizing “Congress' unequivocal”
“approval of, the Corps' regulations interpreting the [Act] to
cover wetlands adjacent to navigable waters”). The Court
has also ruled that the Act's coverage of adjacent wetlands
does not extend to “isolated” wetlands. 

 at 168–172.
   So the question here becomes the meaning of “adjacent”
wetlands under the Clean Water Act. As a matter of ordi-
nary meaning and longstanding agency practice, a wetland is
718                    SACKETT v. EPA

              Kavanaugh, J., concurring in judgment

“adjacent” to a covered water (i) if the wetland is adjoining—
that is, contiguous to or bordering—a covered water—or
(ii) if the wetland is separated from a covered water only by
a man-made dike or barrier, natural river berm, beach dune,
or the like.
    The Court and I agree that wetlands in the frst cate-
gory—that is, wetlands adjoining a covered water—are cov-
ered as adjacent wetlands. Ante, at 671–674. But the
Court and I disagree about the second category—that is,
wetlands separated from a covered water only by a man-
made dike or barrier, natural river berm, beach dune, or the
like. The Court concludes that wetlands in that second cate-
gory are not covered as adjacent wetlands because those
wetlands do not have a continuous surface connection to a
covered water—in other words, those wetlands are not ad-
joining the covered water. I disagree because the statutory
text (“adjacent”) does not require a continuous surface con-
Page Proof Pending Publication
nection between those wetlands and covered waters.
    The ordinary meaning of the term “adjacent” has not
changed since Congress amended the Clean Water Act in
1977 to expressly cover “wetlands adjacent” to waters of the
United States. 

; 

(g). Then as
now, “adjacent” means lying near or close to, neighboring, or
not widely separated. Indeed, the defnitions of “adjacent”
are notably explicit that two things need not touch each
other in order to be adjacent. “Adjacent” includes “adjoin-
ing” but is not limited to “adjoining.” See, e. g., Black's
Law Dictionary 62 (rev. 4th ed. 1968) (defning “adjacent” as
“Lying near or close to; sometimes, contiguous; neighboring;
. . . may not actually touch”); Black's Law Dictionary 50 (11th
ed. 2019) (defning “adjacent” as “Lying near or close to, but
not necessarily touching”); see also, e. g., Webster's Third
New International Dictionary 26 (1976) (defning “adjacent”
as “to lie near, border on”; “not distant or far off”; “nearby
but not touching”).
                   Cite as: 

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              Kavanaugh, J., concurring in judgment

   By contrast to the Clean Water Act's express inclusion of
“adjacent” wetlands, other provisions of the Act use the nar-
rower term “adjoining.” Compare 

(g) with
§§ 1321(b)–(c) (“adjoining shorelines” and “adjoining shore-
lines to the navigable waters”); § 1346(c) (“land adjoining the
coastal recreation waters”); see also § 1254(n)(4) (“estuary”
includes certain bodies of water “having unimpaired natural
connection with open sea”); § 2802(5) (“ `coastal waters' ” in-
cludes wetlands “having unimpaired connection with the
open sea up to the head of tidal infuence”). The difference
in those two terms is critical to this case. Two objects are
“adjoining” if they “are so joined or united to each other that
no third object intervenes.” 1968 Black's 62 (comparing
“adjacent” with “adjoining”); see ibid. (“Adjoining” means
“touching or contiguous, as distinguished from lying near to
or adjacent”); see also Black's Law Dictionary 38–39 (5th ed.
1979) (same); Webster's Third 26–27 (similar). As applied to
Page Proof Pending Publication
wetlands, a marsh is adjacent to a river even if separated by
a levee, just as your neighbor's house is adjacent to your
house even if separated by a fence or an alley.
   In other contexts, this Court has recognized the important
difference in the meaning of the terms “adjacent” and “ad-
joining” and has held that “adjacent” is broader than “adjoin-
ing or actually contiguous.” United States v. St. Anthony
R. Co., 

 (1904). As an example, the St. An-
thony case concerned a federal statute granting railroads the
right to cut timber from “public lands adjacent” to a railroad
right of way. 

. The Court held that
timber could be taken from “adjacent” sections of land that
were not “contiguous to or actually touching” the right of
way. 

. The Court explained that if “the word
`adjoining' had been used instead of `adjacent,' ” a railroad
could not have taken the relevant timber. 

   In short, the term “adjacent” is broader than “adjoining”
and does not require that two objects actually touch. We
720                   SACKETT v. EPA

             Kavanaugh, J., concurring in judgment

must presume that Congress used the term “adjacent” wet-
lands in 1977 to convey a different meaning than “adjoining”
wetlands. See Russello v. United States, 

(1983).
                              II
   Longstanding agency practice reinforces the ordinary
meaning of adjacency and demonstrates, contrary to the
Court's conclusion today, that the term “adjacent” is broader
than “adjoining.”
   After the Act was passed in 1972, a key question quickly
arose: Did “waters of the United States” include wetlands?
By 1975, the Army Corps concluded that the term “waters
of the United States” included “adjacent” wetlands. 

. In 1977, Congress itself made clear that “adja-
cent” wetlands were covered by the Act by amending the
Act and enacting § 1344(g). 

.
   Since 1977, when Congress explicitly included “adjacent”
Page Proof Pending Publication
wetlands within the Act's coverage, the Army Corps has
adopted a variety of interpretations of its authority over
those wetlands—some more expansive and others less ex-
pansive. But throughout those 45 years and across all eight
Presidential administrations, the Army Corps has always in-
cluded in the defnition of “adjacent wetlands” not only wet-
lands adjoining covered waters but also those wetlands that
are separated from covered waters by a man-made dike or
barrier, natural river berm, beach dune, or the like.
  • In 1977 and 1980, under President Carter, the Army
    Corps and EPA defned “adjacent” wetlands as including
    wetlands “separated from other waters of the United
    States by man-made dikes or barriers, natural river
    berms, beach dunes and the like.” 

;
    see 

.
  • In 1986, under President Reagan, the Army Corps
    adopted a new regulatory provision defning “waters of
    the United States” and reaffrmed that “adjacent” wet-
                 Cite as: 

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            Kavanaugh, J., concurring in judgment

   lands include wetlands “separated from other waters of
   the United States by man-made dikes or barriers, natu-
   ral river berms, beach dunes and the like.” 

, 41251.
 • From 1986 until 2015, under Presidents Reagan, George
   H. W. Bush, Clinton, George W. Bush, and Obama, the
   regulations continued to cover wetlands “separated from
   other waters of the United States by man-made dikes or
   barriers, natural river berms, beach dunes and the like.”
   See 

(c) (1991); 

(b) (1991); 

(c) (1998); 

(b) (1998); 

(c) (2005); 

(b) (2005); 

(c) (2010); 

(b) (2010).
 • In 2015, under President Obama, the Army Corps and
   EPA promulgated a new rule, which again specifed that
   “adjacent” wetlands include wetlands “separated by con-
   structed dikes or barriers, natural river berms, beach
Page Proof Pending Publication
   dunes, and the like.” 

, 37116.
 • In 2019 and 2020, under President Trump, the Army
   Corps and EPA repealed the 2015 rule and issued a new
   rule. But even following the repeal and new rule, adja-
   cent wetlands included wetlands that are “physically
   separated” from certain covered waters “only by a natu-
   ral berm, bank, dune, or similar natural feature” or “only
   by an artifcial dike, barrier, or similar artifcial struc-
   ture so long as that structure allows for a direct hydro-
   logic surface connection . . . in a typical year, such as
   through a culvert, food or tide gate, pump, or similar
   artifcial feature.” 

, 22340 (2020).
 • In 2023, under President Biden, the Army Corps and
   EPA once again issued a new rule that defned “adja-
   cent” wetlands to include wetlands “separated from
   other waters of the United States by man-made dikes or
   barriers, natural river berms, beach dunes, and the like.”
   88 Fed. Reg. 3143–3144.
722                   SACKETT v. EPA

             Kavanaugh, J., concurring in judgment

  That longstanding and consistent agency interpretation re-
fects and reinforces the ordinary meaning of the statute.
The eight administrations since 1977 have maintained dra-
matically different views of how to regulate the environ-
ment, including under the Clean Water Act. Some of those
administrations promulgated very broad interpretations of
adjacent wetlands. Others adopted far narrower interpre-
tations. Yet all of those eight different administrations
have recognized as a matter of law that the Clean Water
Act's coverage of adjacent wetlands means more than adjoin-
ing wetlands and also includes wetlands separated from cov-
ered waters by man-made dikes or barriers, natural river
berms, beach dunes, or the like. That consistency in inter-
pretation is strong confrmation of the ordinary meaning of
adjacent wetlands.
                             III
   The Act covers “adjacent” wetlands. And adjacent wet-
Page Proof Pending Publication
lands is a broader category than adjoining wetlands. But
instead of adhering to the ordinary meaning of “adjacent”
wetlands, to the 45 years of consistent agency practice, and
to this Court's precedents, the Court today adopts a test
under which a wetland is covered only if the wetland has a
“continuous surface connection” to a covered water—in other
words, if it adjoins a covered water. Ante, at 684 (internal
quotation marks omitted). The Court says that the wetland
and the covered water must be “indistinguishable” from one
another—in other words, there must be no “clear demarca-
tion” between wetlands and covered waters. Ante, at 678
(internal quotation marks omitted).
   The Court's “continuous surface connection” test disre-
gards the ordinary meaning of “adjacent.” The Court's mis-
take is straightforward: The Court essentially reads “adja-
cent” to mean “adjoining.” As a result, the Court excludes
wetlands that the text of the Clean Water Act covers—
and that the Act since 1977 has always been interpreted to
cover.
                       Cite as: 

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                 Kavanaugh, J., concurring in judgment

   In support of its narrower “continuous surface connection”
interpretation of covered wetlands, the Court emphasizes
that the 1972 Act's overarching statutory term is “waters of
the United States.” Ante, at 676. And the Court suggests
that the term “waters of the United States” cannot be inter-
preted to cover “adjacent wetlands” but only “adjoining wet-
lands.” See ante, at 676–678. But in 1977, Congress itself
expressly made clear that the “waters of the United States”
include “adjacent” wetlands. 

. And Congress
would not have used the word “adjacent” in 1977 if Congress
actually meant “adjoining,” particularly because Congress
used the word “adjoining” in several other places in the
Clean Water Act. 

(b)–(c), 1346(c); see also
§§ 1254(n)(4), 2802(5).
   To bolster its unorthodox statutory interpretation, the
Court resorts to a formula: “A minus B, which includes C.”
Ante, at 675. That just seems to be a fancier way of arguing
(against all indications of ordinary meaning) that “adjacent”
Page Proof Pending Publication
means “adjoining.” But again the Court is imposing a re-
striction nowhere to be found in the text. In the end, the
Court has no good answer for why Congress used the term
“adjacent” instead of “adjoining” when Congress enacted
§ 1344(g) in 1977.1
   Recall again how the 1977 Act came about. In 1975, the
Army Corps concluded that the 1972 Act's coverage of “wa-
ters of the United States” included “adjacent” wetlands. 

. Then in 1977, Congress adopted a new
permitting program for a category of “waters of the United
States.” Congress allocated to the Federal Government ex-
clusive authority to issue Clean Water Act permits for dump-

  1
   Perhaps recognizing the diffculty of reading the Act to mean “adjoin-
ing” when it actually says “adjacent,” the Court at one point suggests that
“adjoining” is equivalent to “adjacent.” Ante, at 676. As a matter of
ordinary meaning, as explained at length above, that is incorrect. Adjoin-
ing wetlands are a subset of adjacent wetlands, not the whole set of adja-
cent wetlands.
724                    SACKETT v. EPA

              Kavanaugh, J., concurring in judgment

ing dredged or fll material into certain “waters of the United
States,” “including wetlands adjacent thereto.” 

. Through that statutory text, Congress made clear its
understanding that “waters of the United States” included
“adjacent” wetlands—and indeed, Congress designed im-
portant federal-state permitting authorities around that pre-
cise understanding. Congress's 1977 amendment did not
“merely” express “an opinion” about the meaning of the
Clean Water Act; rather, it refected what Congress under-
stood “its own prior acts to mean.” Bell v. New Jersey,

 (1983) (internal quotation marks
omitted).
    Moreover, Congress's 1977 decision was no accident. As
this Court has previously recognized, “the scope of the
Corps' asserted jurisdiction over wetlands”—including the
Corps' decision to cover adjacent wetlands—“was specifcally
brought to Congress' attention” in 1977, “and Congress re-
Page Proof Pending Publication
jected measures designed to curb the Corps' jurisdiction.”
United States v. Riverside Bayview Homes, Inc., 

 (1985). Subsequently, this Court has recognized
that Congress's 1977 amendment made clear that the Act
“cover[s] wetlands adjacent to navigable waters.” Solid
Waste Agency of Northern Cook Cty. v. Army Corps of En-
gineers, 

 (2001); see Riverside Bayview, 

 (“Congress expressly stated that the term `wa-
ters' included adjacent wetlands”).
   Not surprisingly, in the years since 1977, no one has seri-
ously disputed that the Act covers adjacent wetlands. And
in light of the text of the Act, eight consecutive Presidential
administrations have recognized that the Act covers adjacent
wetlands and that adjacent wetlands include more than sim-
ply adjoining wetlands. The Court's analysis today there-
fore seems stuck in a bit of a time warp—relitigating an issue
that Congress settled in 1977 and that this Court has long
treated as settled: The Act covers adjacent wetlands. By
                  Cite as: 

 (2023)           725

             Kavanaugh, J., concurring in judgment

adopting a test that substitutes “adjoining” for “adjacent,”
the Court today errs.
  The Court also invokes federalism and vagueness con-
cerns. The Court suggests that ambiguities or vagueness
in federal statutes regulating private property should be
construed in favor of the property owner, particularly given
that States have traditionally regulated private property
rights. See ante, at 679–680; see also Solid Waste Agency
of Northern Cook Cty., 531 U. S., at 173–174. To begin with,
the Federal Government has long regulated the waters of
the United States, including adjacent wetlands.
  In any event, the decisive point here is that the term “ad-
jacent” in this statute is unambiguously broader than the
term “adjoining.” On that critical interpretive question,
there is no ambiguity. We should not create ambiguity
where none exists. And we may not rewrite “adjacent” to
mean the same thing as “adjoining,” as the Court does today.
  Finally, contrary to the Court's suggestion otherwise, the
Page Proof Pending Publication
analysis in this separate opinion centers on the “operative”
text, “waters of the United States.” Ante, at 683–684. To
recap: The 1972 Act covered “waters of the United States.”
In 1977, when Congress allocated permitting authority, Con-
gress expressly included “adjacent” wetlands within the
“waters of the United States.” Since then, the Executive
Branch and this Court have recognized that “waters of the
United States” covers “adjacent” wetlands. Based on the
text of the statute, as well as 45 years of consistent agency
practice and this Court's precedents, I respectfully disagree
with the Court's decision to interpret “waters of the United
States” to include only adjoining wetlands and not adjacent
wetlands.
                              IV
  The difference between “adjacent” and “adjoining” in this
context is not merely semantic or academic. The Court's
rewriting of “adjacent” to mean “adjoining” will matter a
726                    SACKETT v. EPA

              Kavanaugh, J., concurring in judgment

great deal in the real world. In particular, the Court's new
and overly narrow test may leave long-regulated and long-
accepted-to-be-regulable wetlands suddenly beyond the
scope of the agencies' regulatory authority, with negative
consequences for waters of the United States. For example,
the Mississippi River features an extensive levee system to
prevent fooding. Under the Court's “continuous surface
connection” test, the presence of those levees (the equivalent
of a dike) would seemingly preclude Clean Water Act cover-
age of adjacent wetlands on the other side of the levees, even
though the adjacent wetlands are often an important part
of the food-control project. See Brief for Respondents 30.
Likewise, federal protection of the Chesapeake Bay might
be less effective if fll can be dumped into wetlands that are
adjacent to (but not adjoining) the bay and its covered tribu-
taries. See id., at 35. Those are just two of many examples
of how the Court's overly narrow view of the Clean Water
Page Proof Pending Publication
Act will have concrete impact.
   As those examples reveal, there is a good reason why Con-
gress covered not only adjoining wetlands but also adjacent
wetlands. Because of the movement of water between adja-
cent wetlands and other waters, pollutants in wetlands often
end up in adjacent rivers, lakes, and other waters. Natural
barriers such as berms and dunes do not block all water fow
and are in fact evidence of a regular connection between a
water and a wetland. 

; 

,
3118. Similarly, artifcial barriers such as dikes and levees
typically do not block all water fow, 

; 

, and those artifcial structures were often
built to control the surface water connection between the
wetland and the water. 

; 

. The scientifc evidence overwhelmingly demonstrates
that wetlands separated from covered waters by those kinds
of berms or barriers, for example, still play an important role
in protecting neighboring and downstream waters, including
by fltering pollutants, storing water, and providing food
                   Cite as: 

 (2023)           727

              Kavanaugh, J., concurring in judgment

control. See 

; 

(b)(2) (2022);
see also United States v. Riverside Bayview Homes, Inc.,

 (1985). In short, those adjacent wetlands
may affect downstream water quality and food control in
many of the same ways that adjoining wetlands can.
   The Court's erroneous test not only will create real-world
consequences for the waters of the United States, but also is
suffciently novel and vague (at least as a single standalone
test) that it may create regulatory uncertainty for the Fed-
eral Government, the States, and regulated parties. As the
Federal Government suggests, the continuous surface con-
nection test raises “a host of thorny questions” and will lead
to “potentially arbitrary results.” Brief for Respondents 29.
For example, how diffcult does it have to be to discern the
boundary between a water and a wetland for the wetland to
be covered by the Clean Water Act? How does that test
apply to the many kinds of wetlands that typically do not
Page Proof Pending Publication
have a surface water connection to a covered water year-
round—for example, wetlands and waters that are connected
for much of the year but not in the summer when they dry
up to some extent? How “temporary” do “interruptions in
surface connection” have to be for wetlands to still be cov-
ered? Ante, at 678. How does the test operate in areas
where storms, foods, and erosion frequently shift or breach
natural river berms? Can a continuous surface connection
be established by a ditch, swale, pipe, or culvert? See 

. The Court covers wetlands separated from
a water by an artifcial barrier constructed illegally, see
ante, at 678, n. 16, but why not also include barriers author-
ized by the Army Corps at a time when it would not have
known that the barrier would cut off federal authority? The
list goes on.
   Put simply, the Court's atextual test—rewriting “adja-
cent” to mean “adjoining”—will produce real-world conse-
quences for the waters of the United States and will gen-
erate regulatory uncertainty. I would stick to the text.
728                   SACKETT v. EPA

             Kavanaugh, J., concurring in judgment

There can be no debate, in my respectful view, that the key
statutory term is “adjacent” and that adjacent wetlands is a
broader category than adjoining wetlands. To be faithful to
the statutory text, we cannot interpret “adjacent” wetlands
to be the same thing as “adjoining” wetlands.
                        *     *      *
   In sum, I agree with the Court's decision not to adopt the
“signifcant nexus” test for adjacent wetlands. I respect-
fully disagree, however, with the Court's new “continuous
surface connection” test. In my view, the Court's new test
is overly narrow and inconsistent with the Act's coverage of
adjacent wetlands. The Act covers adjacent wetlands, and
a wetland is “adjacent” to a covered water (i) if the wetland
is contiguous to or bordering a covered water, or (ii) if the
wetland is separated from a covered water only by a man-
made dike or barrier, natural river berm, beach dune, or the
like. The wetlands on the Sacketts' property do not fall into
Page Proof Pending Publication
either of those categories and therefore are not covered
under the Act as I would interpret it. Therefore, like the
Court, I would reverse the judgment of the U. S. Court of
Appeals for the Ninth Circuit and remand for further pro-
ceedings. But I respectfully concur only in the Court's
judgment.
                            Reporter’s Note

  The attached opinion has been revised to refect the usual publication
and citation style of the United States Reports. The revised pagination
makes available the offcial United States Reports citation in advance of
publication. The syllabus has been prepared by the Reporter of Decisions
for the convenience of the reader and constitutes no part of the opinion of
the Court. A list of counsel who argued or fled briefs in this case, and
who were members of the bar of this Court at the time this case was
argued, has been inserted following the syllabus. Other revisions may
Page Proof Pending Publication
include adjustments to formatting, captions, citation form, and any errant
punctuation. The following additional edits were made:

p. 652, line 6, “§ 203.3(b)” is changed to “§ 230.3(b)”
p. 655, line 4 from bottom, “Id., at 170, n. 5.” is inserted after § 1362(7)
p. 673, line 8, “Appropriations” is inserted after “Harbors”
p. 683, line 15, “regulatory” is changed to “[regulatory]”
p. 704, line9, “authority” is changed to “power”
p. 708, line 4 from bottom, “economically gainful” is changed to “economic
   or gainful”
p. 709, n. 10, line 1, “included” is changed to “include”