Document ID: ./input/supremecourt_opinions/opinions/22pdf/21-454_4g15.pdf
Page Number: 47

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

13 

THOMAS, J., concurring

  The Daniel Ball test, with minor variations, marked the 
limits  of  federal  jurisdiction  over  waters  up  to  the  enact-
ment of the CWA.  For instance, in Economy Light & Power 
Co. v. United States, 256 U. S. 113 (1921), the Court applied 
The Daniel Ball but expanded it to hold that the River and
Harbor  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.,  311  U. S.  377  (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 reflect the Court’s longstanding
view that the statutory term “navigable water” required ap-
plication of the Daniel Ball test. 

2 
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, 317 U. S. 111, 
127–129 (1942); see also United States v. Darby, 312 U. S. 
100, 119 (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 Con-
gress’ Commerce Clause authority to require licenses under 

—————— 
See, e.g., Swamp Land Act of 1850, ch. 84, 9 Stat. 519; see also S. John-
son,  Wetlands  Law:  A  Course  Source  25–26  (2d  ed.  2018).    Wetlands 
preservation only gained traction due, in large part, to advances in fire-
arms technology that made waterfowl hunting feasible.  G. Baldassarre 
& E. Bolen, Waterfowl Ecology and Management 10–14 (1994).