(CN) – Montana cannot challenge Wyoming’s more efficient irrigation process, even though the increased water consumption deprives its northern neighbor of its usual water allotment, the Supreme Court ruled, 7-1, on Monday.
Congress funds water-storage facilities in the area because snow melt causes flows of the Yellowstone River to vary widely, and the states need every drop for irrigation. Under the Yellowstone River Compact of 1951, Wyoming, Montana and North Dakota each get a share of the water necessary for the uses it required before 1950.
Wyoming gets a certain percentage of any remaining and unappropriated water from the Yellowstone River’s four tributaries, and Montana receives the rest.
The Supreme Court authorized Montana in 2008 to sue Wyoming over an alleged breach of their compact. Montana claimed that Wyoming was exceeding its water share for “new, post-1950 uses,” such as irrigating new acreage, building new storage facilities, conducting new groundwater pumping and increasing consumption on existing agricultural acreage.
Wyoming had increased its net water consumption by improving its irrigation systems’ efficiency with new sprinklers that reduce the amount of wastewater returned to the river – which Montana says has decreased the water volume it collects downstream by 25 percent.
Wyoming could be taking the same amount of water it always has, but it returns less to the river.
A court-appointed special master recommended dismissing the complaint for failure to state a claim, and the Supreme Court agreed on Monday.
“Despite the lack of clarity, the Special Master found several reasons to conclude that Wyoming’s pre-1950 users may switch to sprinkler irrigation,” Justice Clarence Thomas wrote for the majority. “He found that the scope of the original appropriative right includes such a change so long as no additional water is diverted from the stream and the conserved water is used on the same acreage for the same agricultural purpose as before. We agree with the Special Master.”
Though the justices noted that “this area of law is far from clear,” the court found that Montana could not point to any laws, authorities or prior litigation to support its theory.
“For all of these reasons, we hold that the doctrine of appropriation in Wyoming and Montana allows appropriators to improve their irrigation systems, even to the detriment of downstream appropriators,” Thomas wrote.
Montana was never guaranteed a set quantity of water under its agreement, the majority found, even though other compacts offer such guarantees.
Justice Antonin Scalia called this argument “a straw man” in his dissenting opinion.
“Montana does not demand a precise volume of water each year; nor does it insist that its pre-1950 water users always receive enough water to satisfy their pre-1950 needs,” Scalia wrote. “It merely asks that its pre-1950 water users occupy the same position relative to Wyoming’s pre-1950 users in 2011 as they did in 1950 – that whatever would have flowed back into the Yellowstone after Wyoming appropriators’ beneficial uses in 1950 if the river then had this year’s flow, will also flow back this year. In dry years, that may mean some Montanans will have to make do with less or go without.”
Scalia also slammed the majority’s reading as “incomprehensible,” and said the court “substitutes its none-too-confident reading of the common law for the Compact’s definition of ‘beneficial use.'”
“Like the common law, this definition lays out the types of uses that qualify as beneficial and the volume of water an appropriator may claim through his beneficial use,” Scalia wrote. “But the Compact’s focus on whether a use depletes a river’s water supply – not whether it diverts the river’s flow – significantly limits the volume of water to which Wyoming is entitled. For purposes of the Compact, Wyoming may lay claim only to its beneficial users’ net consumption of water, that is, the volume of water diverted from the river minus the volume that flows (or seeps) back into the river’s channel.” (Emphasis and parentheses in original.)
Justice Elena Kagan did not take part in the court’s consideration or decision of the case.