South Carolina v. North Carolina
The Court let a joint water-supply agency and a power company intervene as parties in South Carolina's water-sharing lawsuit against North Carolina, but ruled that the city of Charlotte could not join the case.
The decision refines how demanding the bar is for outside groups to inject themselves into lawsuits between states, keeping most such fights limited to the states themselves while carving out room for entities with truly distinct, cross-border interests.
How it got here: South Carolina filed this dispute directly with the Supreme Court, which appointed a Special Master; the Master allowed all three groups to intervene, and South Carolina objected.
The Case in Depth
What happened
South Carolina sued North Carolina at the Supreme Court, arguing that North Carolina had approved too many water transfers out of the Catawba River basin, leaving South Carolina without its fair share, especially during droughts. Three outside groups named in the lawsuit — a bistate water-supply agency, a power company that dams the river, and the city of Charlotte — asked to join the case as parties rather than leave their interests to the states.
The question before the Court
Should a bistate water-supply agency, a power company, and a city be allowed to join South Carolina's Supreme Court lawsuit against North Carolina over sharing the Catawba River's water?
Why it matters
The ruling determines who gets a formal seat at the table in a high-stakes fight over river water that affects drinking water, power generation, and growth in both Carolinas. By letting the water agency and the power company argue for themselves, the Court ensures their specific operational needs — reservoirs, licenses, and infrastructure deals — will be directly represented, not left to the states to advocate on their behalf.
What changes now
The underlying equitable-apportionment lawsuit between South Carolina and North Carolina continues before the Special Master, now with the water-supply agency and the power company participating as full parties alongside the two states. Charlotte may still weigh in as an amicus but cannot argue as a party. This order resolves only who can participate, not how the river's water will ultimately be divided.
What this does not decide
This decision does not decide how the Catawba River's water should actually be divided between South Carolina and North Carolina — that equitable-apportionment question remains pending before the Special Master. It resolves only which nonstate entities may participate as parties in that ongoing litigation.
Concurrences and dissents
Dissent in part — Justice Roberts
“The result is literally unprecedented: Even though equitable apportionment actions are a significant part of our original docket, this Court has never before granted intervention in such a case to an entity other than a State, the United States, or an Indian tribe. Never.”Roberts's central objection that the majority broke with a long unbroken practice of excluding private entities from water-sharing suits.
Chief Justice Roberts agreed that Charlotte should be denied intervention and that the Special Master's proposed broad intervention rule was wrong, but argued the majority misapplied its own test by letting the water-supply agency and the power company intervene. He stressed that no nonsovereign entity had ever before been allowed to intervene in a water-apportionment case, and that both entities' interests in water use, licenses, and agreements were shared with countless other citizens and thus were properly represented by their states alone. He warned that the ruling could open the door to unlimited private intervention in future interstate water disputes and argued the entities' input could instead be given through amicus briefs.
How the Court got there
The legal reasoning, step by step
- The Court applied the intervention standard from a 1953 case, New Jersey v. New York, which requires anyone whose home state is already a party to show a compelling interest of their own — separate from the interests shared by all other residents of that state — that the state cannot adequately represent.
- The Court declined to adopt a broader intervention rule the Special Master had proposed, reasoning that a compelling reason to let outsiders join one interstate dispute does not automatically justify letting outsiders join every interstate dispute.
- Applying the standard to the water-supply agency, the Court found it uniquely bistate — jointly owned, financed, and regulated by counties in both states — so neither state could fully represent its interest in keeping its delicate two-county financial balance intact during the litigation.
- Applying the standard to the power company, the Court found it had a unique and compelling interest in protecting its federal hydroelectric license and a multi-party agreement setting minimum river flows, interests neither state had signed onto or committed to defend.
- Applying the same standard to the city, the Court found its interest was simply that of one water user among many North Carolina residents, since the lawsuit sought relief against all of North Carolina's excess transfers generally rather than targeting the city specifically, so North Carolina could adequately represent it as parens patriae.
Doctrinal impact
Cases affected by this decision
Reaffirms New Jersey v. New York (345 U.S. 369)
The Court reaffirmed this case's compelling-interest test as the governing standard for letting outsiders join a lawsuit between states.
Distinguishes Oklahoma v. Texas (258 U.S. 574)
The Court distinguished this land-title boundary dispute from the water-sharing context now before it.