A long-running dispute between Georgia and Florida over the use of water from rivers that run through the states was left unresolved June 27 as the U.S. Supreme Court ordered a court-appointed special master to reexamine the dispute.

The fight over water in the Apalachicola-Flint-Chattahoochee river basin has lingered for decades. Florida filed a suit against Georgia in 2012, saying the withdrawals upstream harm the health of the Apalachicola Bay and its oyster population. Georgia says it has taken several actions to reduce its use of water and is only using its fair share.

In 2017, a special master appointed by the high court determined that Florida made a "sufficient showing" that capping Georgia's water usage would benefit Florida. But the special master, Ralph Lancaster, stopped short of dictating a remedy because the court could not order the U.S. Army Corps of Engineers to release water from five dams and four reservoirs in Georgia.

"Because the Corps is not a party, no decree entered by this court can mandate any change in the Corps' operations in the basin," Lancaster wrote in his February 2017 report. "Without the ability to bind the Corps, I am not persuaded that the court can assure Florida the relief it seeks."

Though Lancaster added in his report that the Corps could offset the increased streamflow in the Flint River by storing additional water in reservoirs along the Chattahoochee during dry periods, there "is no guarantee that the Corps will exercise its discretion to release or hold back water at any particular time."

In updating its manual of practice for the basin in March 2017, the Corps said that it would adjust operations accordingly if the Supreme Court apportioned waters of the basin

The Supreme Court, in a 5-4 decision handed down on June 27, said Lancaster "applied too strict a standard" when determining he could not craft a remedy.

"At this stage of the proceeding and in light of these assumptions, Florida made a sufficient showing that the extra water that would result from its proposed consumption cap would both lead to increased streamflow in Florida's Apalachicola River and significantly redress the economic and ecological harm that Florida has alleged," according to the decision written by Justice Stephen G. Breyer. Chief Justice John G. Roberts and Justices Anthony Kennedy, Ruth Bader Ginsburg and Sonia Sotomayor concurred with the opinion.

The court, however, reserved judgement on the case, saying further findings were needed from Lancaster before it could make any decision.

The dissent, written by Justice Clarence Thomas, a Georgia native, said the additional effort was a waste of time. "During their 18 months of discovery," Thomas said, "the parties produced 7.2 million pages of documents, served 130 third-party subpoenas, issued more than 30 expert reports and conducted nearly 100 depositions, including 29 expert depositions. Florida thus had a more-than-ample opportunity to gather its evidence and then present it at a 1-month trial."

In the meantime, fast-growing Atlanta continues efforts to minimize its water use, reducing usage by 10% since 2000. But withdrawals farther downstream for irrigation have increased in recent years, especially during droughts, when the lack of water most harms the bay.

Katherine Zitsch, Atlanta Regional Commission natural resources manager, said in a statement, "We are disappointed this litigation will continue, but we are confident Georgia will prevail in the end."

Zitsch added, "Metro Atlanta is a national leader in water conservation and uses on average only 1.3% of the water in the ACF basin to support a thriving region of more than 5 million people and 2.5 million jobs."

She said, "We appreciate the State of Georgia's vigorous defense of our water use, and look forward to a time when we can move beyond litigation and cooperatively manage the basin's water."

Florida Gov. Rick Scott (R) called the court's ruling "a huge win" for his state. Scott added in a statement posted on Twitter that "we look forward to further securing a healthy Apalachicola Bay while protecting the thousands of jobs that depend on this natural resource."