For conservationists along the Minnesota River, stopping the expansion of the Big Stone power plant has become the single most important goal in decades.

“It’s a proposed corporate water grab from Big Stone Lake. It’s an incredibly dangerous precedent and is against everything Minnesotans stand for,” said Patrick Moore, head of the Montevideo-based group Clean Up the River Environment.

Big Stone Lake, near Ortonville, is in both South Dakota and Minnesota and feeds the Minnesota River.

Five utilities, led by Otter Tail Power, are proposing a $1.5 billion coal plant be built next to an existing power plant. South Dakota has granted its permission, including a permit for the company to annually draw 3.2 billion gallons from Big Stone Lake.

Many environmental groups oppose Big Stone II because of concerns over emissions of carbon and mercury, particulates and sulfur dioxide, which would be carried by prevailing winds into the Minnesota River Valley.

The head of NASA’s Goddard Institute for Space Studies even urged Gov. Tim Pawlenty to publicly oppose the plant because it would increase global warming.

Moore said those issues are important, but he thinks Minnesota officials and environmental groups should be focused on one state awarding water rights on border waters that affect both states.

“This issue is a serious threat, not only to the Minnesota River, but all the waters in the state,” Moore said.

Moore said a Minnesota Department of Natural Resources hydrologist testified they would have allowed only one-third of the water granted to the utilities by South Dakota because of concerns of low-water flows to the Big Stone National Wildlife Refuge and to the river.

The power companies say they won’t need all of the water they have rights to if a new plant is built, leading Moore to believe the utilities are looking to sell the extra water. One possible customer could be an ethanol plant next to the power plant.

“Water is the most precious thing on the planet right now. Who knows what they could do with the water,” Moore said.

“You have a private corporation getting water for free from South Dakota and being able to sell it. It’s an outrage.

“It would never happen if it was on Lake Pepin or Lake Superior or the Boundary Waters, but you’re not hearing about it because of where it is and because the Pawlenty administration isn’t interested.”

Moore said that while Minnesota regulatory agencies are reluctant to step in, there is a longstanding structure set up for dealing with boundary water issues.

The project manager of Big Stone II, Mark Rolfes, wrote in a column to The Free Press last month that the utilities are committed to strong environmental safeguards.