Florida wants to take its “water war” with Georgia to the U.S. Supreme Court.

Florida Gov. Rick Scott said Tuesday he will ask the high court to restrict Georgia’s water use, a not-so-surprising sign that more than two decades of negotiations among Georgia, Alabama and Florida have failed.

Florida’s oyster industry has been decimated in recent years, and the federal government on Monday designated Apalachicola Bay as a fisheries disaster, meaning the area could get federal aid money.

The exact causes of the crisis are in dispute. Scott’s statement Tuesday blames a thirsty Georgia, but even he has acknowledged the role of over-fishing, as well as drought and changing salinity, in depleting the oyster beds.

The downstream states have long alleged that Georgia does not allow enough water to flow down the Chattahoochee River, while metro Atlanta has sought — and recently won — the right to draw from Lake Lanier to serve its growing population.

“This lawsuit will be targeted toward one thing – fighting for the future of Apalachicola,” Scott said in a statement. “This is a bold, historic legal action for our state. But this is our only way forward after 20 years of failed negotiations with Georgia. We must fight for the people of this region. The economic future of Apalachicola Bay and Northwest Florida is at stake.”

Georgia Gov. Nathan Deal said the state has made great strides in water conservation and the threatened suit is politically motivated.

“Gov. Scott’s threat to sue my state in the U.S. Supreme Court greatly disappoints me after I negotiated in good faith for two years,” Deal said. “More than a year ago, I offered a framework for a comprehensive agreement. Florida never responded. It’s absurd to waste taxpayers’ money and prolong this process with a court battle when I’ve proposed a workable solution.”

Deal did not provide details about his proposed solution. Deal and Scott, both Republicans, are up for re-election next year.

Last year, the Supreme Court declined to review a decision by the 11th Circuit Court of Appeals allowing metro Atlanta to tap into Lanier. Scott said that the new lawsuit will seek injunctive relief against Georgia’s water consumption, considering the harm to Florida’s oyster industry.

Tuesday’s announcement was the latest volley in a long-running feud.

“It’s expected,” said Bob Kerr, who was Georgia’s chief water negotiator from 1998 to 2004. “They have consistently, for 20 years now, exercised every effort they could to prevent Atlanta in particular, and Georgia as well, from having the use of the waters that flows through its land.”

The Chattahoochee River joins with the Flint River at the Georgia-Florida line to form the Apalachicola River, which flows 110 miles into the eponymous bay. The confluence of fresh river water and salty Gulf of Mexico water provides a nutrient cocktail that sustains the bay biologically and, therefore, financially.

The bay accounts for 90 percent of Florida’s oyster supply and 10 percent of the nation’s. Oysters valued at $7 million landed dockside in Franklin County in 2011, according to Florida officials. Hundreds of oystermen, seafood processors and truck drivers depend on the bivalve mollusk’s bounty for their livelihood.

Scott added that Georgia’s “unchecked and growing consumption of water” unfairly depletes the Apalachicola of fresh water and raises salinity levels that have increased diseases and predatory activity against oysters in the bay. Low water levels upset the delicate fresh-to-salt water ratio that oysters need to survive.

But drought – and the divvying up of ever-precious fresh water between Georgia and Florida — is the perceived real culprit. The Southeast suffered record drought during the middle of the previous decade as Atlantans, forbidden the watering of their lawns, well remember.

Conditions improved in 2009 and 2010 with relatively normal rainfall amounts and river flows. But the rains petered out again in 2011 and 2012 plunging swaths of Southwest Georgia and the Florida Panhandle into another dry era.

The National Oceanic and Atmospheric Administration announced Monday that the drought resulted in a fishery disaster for Florida’s oystermen, as officials estimated that the Gulf’s oyster industry declined 60 percent over the last year.

This year’s heavy rainfalls have provided a reversal. Last month, the state temporarily closed two Apalachicola Bay oyster harvesting areas because of high river levels.

Concerns have been raised that over-fishing by the Gulf’s oystermen has contributed to the fishing disaster. Most oyster beds – but not Apalachicola’s — were closed after the 2010 Gulf oil spill.

“This led to over-harvesting of illegal and sub-legal oysters further damaging an already stressed population,” Scott said in a statement last September.

Scott’s announcement came as he toured the Apalachicola Bay with U.S. Sens. Marco Rubio and Bill Nelson of Florida, after a Congressional field hearing designed in part to allow Floridians to air their grievances against Georgia.

“If their water is low up there, they can’t ride their little jet ski up in their favorite cove or they can’t tie their boat to their dock,” said Jon Steverson, the executive director of the Northwest Florida Water Management District. “For our guys, it’s how they make a living. It’s time to focus on upstream conservation.”

But Katherine Zitsch, the director of natural resources for the Atlanta Regional Commission, said the metro area has “one of the most aggressive water conservation programs in the country.” Even as the region’s population grew by 6 percent from 2006 to 2009, she said, its water use declined by 15 percent.

Still, the metro area is asking the U.S. Army Corps of Engineers for permission to withdraw up to 705 million gallons a day to meet the region’s needs through 2030 — a major leap from the roughly 360 million gallons the region now uses.

Florida’s lawsuit threat comes after a string of court victories for Georgia has tipped the water wars in its favor. And Georgia lawmakers have, thus far, thwarted efforts by Florida and Alabama to get Congress to weigh in on the dispute, through a water resources bill.

Nelson on Tuesday acknowledged that it would be hard to outmaneuver the Georgia delegation and thus asked the Corps to hurry up with rewriting half-century-old water manuals. The manuals are not scheduled to be available to the public until 2015.