North Dakota

The state has constructed a barrier that will screen the lake's water, keeping potentially harmful alien species from Manitoba's rivers, when water begins to flow between the two regions as early as next week.

"It's a good development, because it's both sides trying to move more to the middle to address the other side's concerns on the Devils Lake issue," Lance Yohe, of the Red River Basin Commission, told CTV News.

Problems began when North Dakota decided to ease chronic flooding in the area by building an outlet to drain Devils Lake into a nearby river -- a river that drains into Canada.

Manitoba fought the move in court, saying it will permit invasive species to enter the Red River and Lake Winnipeg.

It also says water from Devils Lake is heavily polluted and would damage water quality in the Red River.

Manitoba Premier Gary Doer told CTV News that he's not satisfied with the gravel filter -- calling it a temporary measure -- and expects the state to do more.

"We've made a positive accommodation with this 18-foot filter, but we need a much more comprehensive long term solution to the water quality issues in Devils Lake," he said.

Some commercial fishers are concerned that Devils Lake contains striped bass, which is a natural predator of pickerel and other fish – species that many fishers depend on for their livelihood.

"Every time you get a predator, you're always worried to death, because you don't know what it's going to do," commercial fisher Robert Kristjanson told CTV News.

While some experts believe an expensive sand filter would be far more reliable, American officials are satisfied with the screen that's already in place.

"It will keep out fish, and some parasites, and the state has gone above and beyond what was requested," Joe Belford, the Ramsey County Commissioner in North Dakota, told CTV News.