JEFFERSON CITY, Mo. (Legal Newsline)-Missouri Attorney General Chris Koster has sued the U.S. government to thwart the planned diversion of Missouri River water to North Dakota.

The U.S. Department of Interior last month approved the $17.5 million water treatment plan for the Northwest Area Water Supply project, which would redirect about 15,000 acre feet of water annually from Lake Sakakawea.

The water would go to taps in northwestern North Dakota. Koster said the plan poses "actual and imminent harm to Missouri citizens."

Koster, a Democrat, says the federal government erred when it failed to consider how the plan would affect downstream states or whether there were alternatives to the plan.

The attorney general filed the lawsuit in U.S. District Court in Washington. He is suing the U.S. Bureau of Reclamation and the U.S. Army Corps of Engineers, which manages the Missouri River's dams.

Koster is asking a federal judge to rule that because officials did not consider environmental impacts of the project that the plan violates the federal National Environmental Policy Act, or NEPA, and should therefore be blocked.

"Under the Corps plan, Missouri stands to lose water at a time of year when it's direly needed for a multitude of uses, including navigation and drinking water supplies," Koster said. "The Corps has neither considered any alternatives to this plan, nor the environmental impact it would have on Missouri and other states downstream from the project."

From Legal Newsline: Reach staff reporter Chris Rizo at chrisrizo@legalnewsline.com.