The water slated to be transferred, 13.3 million tonnes a year through a 72 kilometre-long pipeline, would be used around Minot, N.D. and would drain into the Souris River, flowing into Manitoba. Manitoba has been fighting the transfer, known as the Northwest Area Water Supply project, in the U.S. court system since 2002, claiming the venture violated U.S. law and risked causing irreparable harm through the potential spread of species not naturally found in Canada.

Manitoba welcomed the decision. "While the future of the project is still uncertain, today's ruling will assist in achieving adequate measures to protect Manitoba's valuable water, including Lake Winnipeg ... from the threat of harm posed by invasive species," said Christine Melnick, Manitoba's Minister of Water Stewardship.