Talk about border disputes, and one immediately thinks of two countries fighting over land demarcations. Another critical issue at the center of many border disputes is water. Countries have often gone to war over what is arguably the earth's most precious resource. It can spawn disputes even within a country's borders. In the United States, a battle over the use of water resources is being fought in the courts. The dispute over the Potomac River that divides the states of Maryland and Virginia is older than the nation itself.
Foreign policy is the domain of the federal government. But regarding U.S. domestic concerns, governments at the state, county, and town levels usually have jurisdiction. And sometimes that puts neighboring states at odds with each other, especially when it comes to sharing resources.
Take the eastern states of Maryland and Virginia. They are sparring over control of access to the water of the Potomac River that separates them.
"The Potomac River is actualy property of the state ot Maryland, not a river that is half Virginia or half Maryland," said Maryland State Legislator Jean Cryor. "It separates the two states, but it's Maryland's."
The river was part of territory granted by King Charles I of England in 1632 that later became the state of Maryland. Negotiators from the two states first resolved their differences over control of the river in 1785, by granting Virginia the right to build on its shoreline and access its resources. That access is once again at the center of the interstate dispute.
In 1996, Fairfax Water Authority of Virginia asked Maryland for permission to extend an intake pipe into the middle of the river. The idea was to bring in fresh water for more than one million residents of three Virginia counties.
That angered Maryland resident John Mathwin, a high school teacher and canoeist. He says Virginia was reaching far into the Potomac because development already had polluted tributaries that flowed into the river.
"It seemed like such a clear-cut case of an organization not doing what it should be doing, a water authority completely indifferent to what all water authorities should do, protect the headwaters," he said. "That is how you get clean water."
Mr. Mathwin lobbied Maryland politicians and environmentalists to prevent the new construction.
Maryland State Legislator Jean Cryor, who took up the cause, accuses her neighboring state of abusing the river for what she calls unbridled development.
"We have put so many federal dollars into cleaning up the Potomac River," she said. "You have to respect what was done, and not allow a new wave to come along and say, well, the river is just a place to get water, and we are not going to worry about the damage we do."
At first, Maryland rejected Virginia's petition to build the intake pipe. So, Virginia took Maryland to court. Maryland then gave Virginia the green light, but limited the water it could collect from the river. The intake system began operating earlier this year.
Virginia still decided to take the case to a higher authority. Attorney Stuart Raphael has argued the case for Virginia's Fairfax Country Water Authority. He declines to talk about the dispute while it is being deliberated in the Supreme Court.
But in an earlier interview with VOA, Mr. Raphael stressed that it is Virginia's access to water that is at stake.
"We have enough water to supply our needs through the year 2020, even assuming an historic drought of record," he said. "After 2020, we are going to need additional water resources, and the states are going to have to cooperate to do that."
Mr. Raphael explains it is also a question of protecting Virginia's rights as an equal.
"At the moment, Maryland has a legal system in place, which doesn't treat Virginia as an equal," he said. "If Virginia wins the case, Virginia is an equal with Maryland, as it should be. They are equal sovereigns. And they can work better together to address their mutual interests."
A Special Master appointed by the Supreme Court last year decided in favor of Virginia's right of access under existing agreements. The case is under consideration in the Supreme Court for a final ruling.
Maryland legislator Cryor points to natural tensions between the states over more than just water.
"They are two different states," she said. "There is no question their tax policies are different. Their development policies are different, and there has always been a natural tension between the two states."
With a slight laugh, Ms. Cryor mentions the two states fought against each other in the Civil War more than a century ago. Still, she points out how much the neighboring states are tied together for commerce and pleasure.
Joe Hoffman of the Interstate Commission on the Potomac River Basin says the fight over the Potomac's water has not spilled over into other areas of cooperation.
"People recognize that this is one issue that stands between the two states," he pointed out. "But I think there are other issues that Maryland and Virginia are cooperating on, particularly with regard to this area and other issues confronting the governors and various departments - environment, natural resources, transportation."
The Supreme Court's ruling on the case is not expected before the middle of next year.