Montana wins a round in water lawsuit

A U.S. Supreme Court appointee has rejected Wyoming's bid to dismiss a lawsuit in which it is accused, by Montana, of taking too much water from rivers shared by the two states.

Montana filed its lawsuit before the nation's highest court in 2007. The suit alleged Wyoming's agriculture and energy industries were pulling too much water from the Tongue and Powder rivers, tributaries of the Yellowstone. The case is before Special Master Barton Thompson, a Stanford University water-law expert appointed by the court.

The outcome could have profound consequences for farmers and others who depend on the rivers, which course through an arid plain where water is considered a precious commodity.

In a written opinion released Wednesday, Thompson shot down several of Wyoming's arguments over why it is not violating terms of a 1950s water agreement between the states.

However, he did not settle whether Wyoming was actually using too much water, and Wyoming Attorney General Bruce Salzburg repeated Wednesday that he believes his state never has broken the agreement.

Montana never quantified how much water it believes Wyoming to be using.

Montana Attorney General Steve Bullock said that in rejecting some of Wyoming's key arguments, Thompson had set the legal "guideposts" within which Montana can prove its case.

"It's setting a legal standard for how much water can be appropriated (by Wyoming) and how much needs to get to Montana," Bullock said. "This is going to be shaping the ability to have water in those basins going forward, presumably forever."

Wyoming had argued that much of the water used by its residents and businesses was not covered by the agreement, known as the Yellowstone River Compact.

The compact, signed by North Dakota, Wyoming and Montana in 1950 and ratified by Congress in 1951, was intended to settle water rights claims in the Yellowstone basin. Wyoming has claimed more recently that water rights predating the compact were not protected under the document.

After being asked to dismiss the case on those grounds, Thompson wrote in a 43-page opinion, signed Tuesday, that pre-1950 water rights were "unambiguously" protected.

Thompson said those protections also extend to the withdrawal of groundwater _ that is, water carried not by the two rivers but found within underground aquifers or other locations across the basin. Groundwater often feeds into nearby rivers.

Montana officials contend that hundreds of billions of gallons of groundwater pumped to the surface by Wyoming's coal-bed methane industry should be counted under the compact.

Wyoming's attorneys had argued that the officials who drafted the 1950 compact never meant to govern groundwater.

The compact does not include the term groundwater. But it makes references to "springs and swamps", which Thompson indicated were often synonymous with groundwater.

"The language reflects a clear intent to cover all sources of water for the Yellowstone River and its tributaries," he wrote.

Thompson's opinion favored Wyoming on two other issues.

He wrote that the compact does not require Wyoming reservoirs stocked when water is plentiful to release that water later, when supplies run short downstream in Montana. And he said Wyoming farmers are not prohibited from using more efficient irrigation systems simply because those systems use more water.

Wyoming's Salzburg acknowledged that the decisions in his state's favor were less significant than those that went Montana's way. But he said the case was far from over.

"All this does is say the case can go forward on some issues," he said. "We're very early in the whole process."

Salzburg and Bullock said the opinion was being closely examined by their respective attorneys to determine if they will ask the Supreme Court to review any of Thompson's findings. If not, the case could begin moving toward trial.