WASHINGTON (Legal Newsline)- In the dispute over water rights of the Catawba River, the U.S. Supreme Court on Wednesday said that the Catawba River Water Supply Project and Duke Energy Carolinas meet the standards for intervention even though they are non-state entities.

The high court found the intervention rule too broad.

"A compelling reason for allowing citizens to participate in the original action is not necessarily a compelling reason for allowing citizens to intervene in all original actions," Associate Justice Samuel Alito wrote for the majority.

The Catawba River runs through both North Carolina and South Carolina and provides drinking water and electricity to millions of people.

South Carolina Attorney General Henry McMaster filed a lawsuit in 2007 to stop a plan that would allow two North Carolina cities to pump up to 10 million gallons of water a day from the Catawba and Yadkin rivers, both of which cross stateliness with South Carolina.

Although, Charlotte, N.C., had been a participant in the lawsuit the justices barred the city from being involved in the battle.

Alito wrote on behalf of the court: "Charlotte has not carried its burden of showing a sufficient interest for intervention in this action."

McMaster had this to say about the ruling: "The city of Charlotte is the largest water consumer along the Catawba River basin and in North Carolina. Their dismissal removes a major legal and political obstacle and will now allow South Carolina's case to move toward resolution before the court."

Last year, U.S. Solicitor General Edwin Kneedler argued that third parties should be kept out of the dispute because they "do not have a sufficiently distinct interest at stake to justify allowing them to interject themselves."

Duke's interest include operating 11 dams and reservoirs in both North Carolina and South Carolina and holds a 50 year federal license that regulates the production of hydroelectric power and has a 70 member stakeholder group from both states.

Alito said that Duke's license from the Federal Energy Regulatory Commission "regulates the very subject matter in dispute: the river's minimum flow into South Carolina."

In an effort to settle the dispute McMaster, reached out to North Carolina in a letter.

"A negotiated settlement is the wisest course for both states. As you recall, South Carolina proposed this course of action before the lawsuit was filed by this state," McMaster wrote.

Energy companies and water utilities account for 92 percent of the water pulled from North Carolina Rivers. Public water consumption accounts for only 10 percent of that. The majority is used to cool its nuclear reactors and power its hydroelectric dams.

Justice Robert's opinion agrees that Charlotte should not be a participant but he disagrees with allowing Duke and the Catawba River Water Supply Project to intervene.

"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," he wrote.