It’s smart to heed good advice, particularly when it comes from someone who can punish you if you don’t. Ralph Lancaster, appointed by the U.S. Supreme Court as special master in a decades-long fight over water rights between Florida and Georgia, qualifies as such a person.

“I urge you, again, to try to settle this matter,” Lancaster told attorneys for both states earlier this month. “… whatever the result is, whatever the court does with this case after I make my report, we’re talking a lot of money and a result that I suggest neither one of you may be very happy with. So, again, and again, and again, I’m going to urge you to discuss settlement seriously.”

That was less a threat than an observation. Court-imposed solutions tend to have all the subtlety and flexibility of a sledgehammer. And in trying to manage a resource as complex as the Chattahoochee, Flint and Apalachicola rivers, subtlety and flexibility are priorities. That’s why Gov. Nathan Deal has been meeting with fellow governors in Alabama and Florida to try to solve this mess out of court, in less adversarial settings. Should Deal succeed, it would be a crowning achievement.

The good news is that Deal and his colleagues now have a successful model to emulate. Since 2008, a group of stakeholders from Alabama, Florida and Georgia have been meeting without official sanction to try to accomplish what politicians, lawyers and bureaucrats have not been able to accomplish. They include representatives from all sections of the 500-mile-long watershed, from oystermen in Apalachicola Bay to environmental groups in north Georgia. They have talked, shared viewpoints and data and tried to reach consensus.

Early on, after it became apparent that they needed data and science to fuel their work, they raised $1.7 million in private capital to provide that science. The result, after seven years of work, is a 130-page “sustainable water management plan” for the whole basin, in which they address contentious issues and reach consensus on most of them.

Some of it’s good news for Atlanta. The report documents that the metro region is not the villain in the story, but in fact has taken significant steps to reduce its impact on downstream neighbors. It found that all of north Georgia, including metro Atlanta, consumes less than half as much water from the basin as do farmers in south central Georgia.

The report also makes a variety of policy suggestions, including raising the water levels at Lake Lanier by two feet, thus adding 25.4 billion gallons of storage. However, it casts significant doubt on Deal’s plan to build new reservoirs, noting that “stakeholders do not agree that new surface-water reservoirs or aquifer storage … are environmentally sustainable.”

Its most important recommendation is that Alabama, Florida and Georgia agree to a “transboundary institution” that allows the three states to work out their differences just as the stakeholders did, by drawing upon science, and by collaborating and cooperating rather than by filing suit.

“Competing interests are understandable, but the absence of a mechanism to work through differences must not continue,” they conclude.

That too is very wise advice that should be heeded.