Document ID: ./input/supremecourt_opinions/opinions/22pdf/21-454_4g15.pdf
Page Number: 27.0

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

21 

Opinion of the Court 

This  is  the  thrust  of  observations  in  decisions  going  all 
the  way  back  to  Riverside  Bayview.  In  that  case,  we  de-
ferred to the Corps’ decision to regulate wetlands actually
abutting a navigable waterway, but we recognized “the in-
herent  difficulties  of  defining  precise  bounds  to  regulable 
waters.”  474 U. S., at 134; see also id., at 132 (noting that
“the transition from water to solid ground is not necessarily
or  even  typically  an  abrupt  one”  due  to  semi-aquatic  fea-
tures like shallows and swamps).  In such a situation, we 
concluded, the Corps could reasonably determine that wet-
lands “adjoining bodies of water” were part of those waters. 
Id., at 135, and n. 9; see also SWANCC, 531 U. S., at 167 
(recognizing  that  Riverside  Bayview  “held  that  the  Corps 
had . . . jurisdiction 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 wa-
ters of the United States,” such that it is “difficult to deter-
mine where the ‘water’ ends and the ‘wetland’ begins.”  547 
U. S.,  at  742,  755  (emphasis  deleted).    That  occurs  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.”  Id.,  at  742;  cf.  33  U. S. C.  §2802(5)  (defining 
“coastal  waters”  to  include  wetlands  “having  unimpaired 
connection with the open sea up to the head of tidal influ-
ence”).  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 con-
nection  may  sometimes  occur  because  of  phenomena  like
low tides or dry spells.16 

—————— 

16 Although a barrier separating a wetland from a water of the United 
States would ordinarily remove that wetland from federal jurisdiction, a