Document ID: ./input/supremecourt_opinions/opinions/boundvolumes/558bv.pdf
Page Number: 442.0

Cite as: 558 U. S. 256 (2010) 

281 

Opinion of Roberts, C. J. 

(1940).  In  those  cases,  Wyoming  sought  to  enforce  this 
Court’s earlier decree apportioning the Laramie River.  See 
Wyoming  v.  Colorado,  260  U. S.  1  (1922).  We  held  that  the 
decree  controlled  the  allocation  of  water  between  Wyoming 
and Colorado, not within them.  As we recognized, our deci­
sion  apportioning  the  river  did  not  “withdraw  water  claims 
dealt  with  therein  from  the  operation  of  local  laws  relating 
to  their  transfer  or  .  .  .  restrict  their  utilization  in  ways  not 
affecting the rights of one State and her claimants as against 
the  other  State  and  her  claimants.”  298  U. S.,  at  584. 
Thus,  although  the  decree  referred  to  particular  uses  of 
water  in  Colorado,  we  held  that  those  individual  uses  could 
vary  from  the  terms  set  out  in  the  decree,  so  long  as  the 
total diversion of water in Colorado was no greater than the 
decree  allowed.  See  id.,  at  584–585;  309  U. S.,  at  579–581. 
We  reiterated  the  point  in  Nebraska  v.  Wyoming,  325  U. S. 
589, 627 (1945), observing that the apportionment of a water­
way between  the States  has only an  “indirect effect”  on the 
rights of individuals within the States. 

All this explains our long history of rejecting attempts by 
nonsovereign  entities  to  intervene  in  equitable  apportion­
ment actions.  New Jersey v.  New York was itself an equita­
ble  apportionment  suit,  and  we  denied  intervention  in  that 
case.  We have  also summarily  denied motions  to intervene 
in  other  water  disputes  between  the  States.  See  Arizona 
v.  California,  514  U. S.  1081  (1995);  Arizona  v.  California, 
345  U. S.  914  (1953);  Nebraska  v.  Wyoming,  296  U. S.  548 
(1935);  Wisconsin  v.  Illinois,  279  U. S.  821  (1929).  And  we 
have strongly intimated in other decisions (albeit in dictum) 
that private entities can rarely, if ever, intervene in original 
actions  involving  the  apportionment  of  interstate  water­
ways.  See  United  States  v.  Nevada,  supra,  at  538  (“[I]ndi­
vidual  users  of  water  .  .  .  ordinarily  would  have  no  right 
to  intervene  in  an  original  action  in  this  Court”);  Nebraska 
v.  Wyoming,  515  U. S.,  at  22  (“We  have  said  on  many  occa­