With both Texas and New Mexico suffering from multiple years of serious drought it comes as no surprise that the Attorney Generals of both states are gearing up for what could be a monumental legal battle now that the U.S. Supreme Court has cleared the way for Texas to argue their case in the highest federal court over what they charge is a violation of a water sharing agreement.

In dispute is a long-standing issue of the way the two states divide water from the Rio Grande. Both states previously reached an agreement on how to divide up the waters of the river with the assistance of federal resource management officials. But after Texas charged New Mexico water officials with violating that agreement as a result of groundwater pumping from the Rio Grande basin, they asked last January that the dispute be elevated to nation's highest court.

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On Monday, Jan. 27, the Supreme Court ruled that the case could be presented before Chief Justices and instructed attorneys for both states to prepare their briefs. But the court also provided a quick settlement clause to New Mexico officials by leaving the door open for them to file a motion within 60 days seeking the case's dismissal.

The question of who owns the water in the river and how it will be divided dates back generations, but in recent years drought conditions and agricultural growth have complicated water issues and how the resource is best managed between the two states. After much disagreement and legal horn rattling, both sides reached an agreement in 2008 with federal support that dictated how water from the river would be shared, thereby avoiding what both sides considered a costly and possible lengthy legal battle.

But as drought conditions prevailed across multiple years, New Mexico Attorney General Gary King filed a lawsuit in 2011 designed to invalidate the interstate water agreement. King's office charged that New Mexico was giving up too much water to Texas and wanted the court to settle the dispute.

Water treaty complicates issue

Complicating the issue is a 1944 water treaty between the United States and Mexico that gives up a portion of all Rio Grande water to Mexican water officials because the river serves as an international border between the two countries. Mexican officials charged that since the border falls in the middle of the river, half of that water stream belongs to them.

The water left over is the amount that has become the subject of disagreement between the two states.

In response to King's lawsuit, Texas officials last year petitioned the Supreme Court to hear the case, charging that any and all lower courts do not have adequate authority to settle the water issue or to rule on the 2008 interstate water agreement entered into by the two states. The high court's decision this week clears the way for litigation to proceed, but it also provides New Mexico officials the right to offer reasons why the case should be dismissed.

While King says he welcomes the chance for New Mexico to present its side of the story to the Supreme Court, some New Mexico farmers have expressed concern. While the 2008 operating agreement "may not be perfect," they argue it does provide a guarantee that some of the river water can be used for New Mexico agriculture.

Some growers in southern New Mexico fear that King's lawsuit could result in a settlement that could favor Texas, making less water from the river available to New Mexico farmers.

In response to the Supreme Court's announcement this week, King says he was disappointed the high court didn't throw out the arguments presented by Texas officials, but said he hopes to convince the high court to dismiss the case. Failing that, he said he expects it could take years before any judgment is reached in the case.

If the high court fails to dismiss the case as King hopes, each state is allowed a maximum 120 days to file a new set of legal briefs on the issue as placed before the court by Texas officials.

Also of interest:

Texas faces water shortage without water plan

Mexico's water crisis may shed light on water treaty non-complian…

Red River water battle victory to Oklahoma