U.S. Army Corps Grants Permit for Michigan Pipeline Tunnel Amid Tribal Opposition

The U.S. Army Corps of Engineers has signed off on a permit for Enbridge Energy to construct a tunnel beneath the Straits of Mackinac, replacing a four-mile portion of the Line 5 pipeline that carries oil and natural-gas liquids from Wisconsin to Ontario. The Corps concluded the project complies with the Clean Water Act, does not impair tribal treaty rights, and would lessen the chance of leaks from anchor strikes. The approval, accelerated under President Donald Trump’s national energy emergency order, provoked sharp criticism from tribal leaders such as Austin Lowes, who called the move “disrespectful and ludicrous.”

Although the federal permit is in hand, Enbridge still needs state approvals; the Michigan Department of Environment, Great Lakes and Energy is reviewing a wastewater discharge permit, and the Michigan Supreme Court recently sent a state permit back for further review. Ongoing litigation includes challenges from the tribes, the state’s appeal of a 2020 federal ruling, and a U.S. Supreme Court decision that will shape future court proceedings on the pipeline’s operation. Lawyers for the tribes say they will continue to fight to protect treaty-guaranteed hunting, fishing and cultural sites.