As The Atlanta Journal-Constitution has warned, the Okefenokee National Wildlife Refuge is facing a nearly unprecedented threat to its existence. In February, Georgia’s Environmental Protection Division sought public comment on proposed permits that would allow Twin Pines Minerals to extract titanium sands (used primarily as a whitener for household products such as paint and toothpaste) along the ridgeline that holds the refuge’s surface and groundwaters in place.

Mining there could doom the refuge’s amazing, 680-square-mile ecosystem that sustains a rich array of wildlife, including migrating birds and imperiled species, such as the red-cockaded woodpecker and the wood stork, and attracts 700,000 visits annually, generating $64 million for local communities.

The Okefenokee faced a similar danger 30 years ago when DuPont proposed a similar project, only to abandon it after a wave of local and national opposition. Though the current proposal also is controversial, it looks as if public sentiment is not going to be enough to save this unique refuge and beloved wilderness, which the Department of the Interior has nominated as a World Heritage Site. Indeed, forceful federal action will be needed to head off this latest threat and put an end to such proposals.

Though the Army Corps of Engineers has disclaimed any regulatory jurisdiction over the proposed mine, fortunately, the federal government can bring a powerful tool to bear in this fight. In January, the regional director of the U.S. Fish & Wildlife Service, which manages the refuge, warned the Georgia EPD that its permit decision must consider “federal reserved water rights.”

These rights are created whenever the United States decides to safeguard federal land for purposes that need water. The Supreme Court developed this legal doctrine in 1908, in a case involving land set aside for Native American tribes in Montana. The court made clear in decisions in 1963 and 1976 that reserved water rights also are created when the United States establishes national wildlife refuges, parks, monuments and other protected federal land areas where water is required.

These and numerous lower court decisions have left no doubt that the doctrine applies to underground as well as surface water and limits the ability of states to authorize water uses that conflict with such preexisting rights.

The reserved rights doctrine has rarely been invoked in the eastern part of the nation, where water conflicts tend to be much rarer than in the arid west. But as the Reagan administration’s Office of Legal Counsel concluded in a comprehensive 1982 legal opinion, the doctrine applies to any federal lands the United States acquires to serve federal objectives that require water. This includes the Okefenokee National Wildlife Refuge, where the U.S. purchased the land in the 1930s for the specific purpose of safeguarding its habitat for migratory birds and other wildlife.

Besides protecting a treasured landscape, bringing the reserved water rights doctrine to bear here would underscore that federal land protections requiring water have to be taken into account as climate change continues to alter hydrologic cycles just about everywhere. Indeed, one of the concerns at the Okefenokee is that the hydrologic disruption caused by mining would likely exacerbate the risk of catastrophic fires both on and off the refuge, a risk that will only escalate as the climate becomes more unstable.

Relying on the reserved water rights doctrine has, to be sure, sometimes produced conflict. But it also has led to many success stories. Indeed, in numerous places in arid states such as Utah, Montana and Colorado, federal-state negotiations have succeeded in putting in place lasting protections to threatened federal lands without unduly hampering the exercise of water rights under state law.

The United States needs to be ready to sue in federal court to enforce its reserved water rights if the state’s EPD allows Twin Pines to proceed while disregarding the water needs of Okefenokee National Wildlife Refuge. As Bruce Babbitt, Interior secretary during the Clinton administration, said in the 1990s in opposing the DuPont mining proposal, “Titanium is a common mineral, while the Okefenokee is a very uncommon swamp.”

That is still the case. If the Okefenokee is to be protected, the U.S. Department of Justice might have to act soon.

John D. Leshy was solicitor (general counsel) of the U.S. Department of the Interior from 1993 to 2001. He is the coauthor of a water law textbook now in its sixth edition, and he recently published a comprehensive political history of America’s public lands, “Our Common Ground.” He is a distinguished professor emeritus at the University of California College of the Law in San Francisco.