Document ID: ./input/supremecourt_opinions/opinions/22pdf/21-454_4g15.pdf
Page Number: 17.0

Cite as:  598 U. S. ____ (2023) 

11 

Opinion of the Court 

away”).

More recently, the agencies have engaged in a flurry of
rulemaking defining “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  cate-
gorically 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 in-
direct tributaries of interstate or traditional navigable wa-
ters, to a case-specific determination for significant nexus. 
Ibid. 

The  agencies  repealed  this  sweeping  rule  in  2019.  84 
Fed. Reg. 56626.  Shortly afterwards, they replaced it with
a narrower definition that limited jurisdiction to traditional
navigable  waters  and  their  tributaries,  lakes,  and  “adja-
cent” wetlands.  85 Fed. Reg. 22340 (2020).  They also nar-
rowed the definition of “[a]djacent,” limiting it to wetlands
that “[a]but” covered waters, are flooded by those waters, or
are separated from those waters by features like berms or 
barriers.  Ibid.  This rule too did not last.  After granting 
the EPA’s voluntary motion to remand, a District Court va-
cated  the  rule.  See  Pascua  Yaqui  Tribe  v.  EPA,  557 
F. Supp. 3d 949, 957 (D Ariz. 2021). 

The  agencies  recently  promulgated  yet  another  rule  at-
tempting  to  define  waters  of  the  United  States.    88  Fed. 
Reg. 3004 (2023) (to be codified in 40 CFR §120.2).  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.  88 

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11 EPA  &  Dept.  of  the  Army,  Economic  Analysis  of  the  EPA-Army

Clean Water Rule 11 (2015).