Feds approve Enbridge Line 5 tunnel, but construction remains blocked

The U.S. Army Corps of Engineers approved Enbridge’s delayed Line 5 oil tunnel permit for work beneath the Straits of Mackinac, clearing a major federal step on Aug. 12. The permit, after six years of review, concluded the project complies with federal environmental laws and is “not contrary to the public interest.” It authorizes about a four-mile tunnel through bedrock beneath where Lake Michigan and Lake Huron meet, and relates to wetlands and waters under federal jurisdiction. Enbridge still cannot begin digging because the Michigan Supreme Court vacated a 2023 state Public Service Commission approval on July 31. Enbridge’s $500 million–class tunnel plan calls for a 21-foot, 30-inch Line 5 segment and about six years of construction, but court limits and additional state approvals remain blocking.