Enbridge Inc. secured a federal permit from the U.S. Army Corps of Engineers on August 12, 2026. The approval authorizes a tunnel under the Straits of Mackinac for the Line 5 pipeline replacement. This milestone concludes a six-year federal review process for the Great Lakes Tunnel Project.
The project will encase a four-mile pipeline segment in a concrete tunnel beneath the lakebed. State-level legal and regulatory challenges persist despite the federal clearance. The Michigan Supreme Court recently ordered state regulators to reconsider a separate key permit before construction begins.