Michigan Supreme Court Voids Key Line 5 Tunnel Permit in 6-1 Ruling
Updated
Updated · bridgemi.com · Aug 1
Michigan Supreme Court Voids Key Line 5 Tunnel Permit in 6-1 Ruling
3 articles · Updated · bridgemi.com · Aug 1
Summary
A 6-1 Michigan Supreme Court ruling sent the Line 5 tunnel permit back to the Public Service Commission, ordering a fresh review that could further delay a project already stalled for eight years.
The court said regulators used an overly narrow environmental analysis, failed to weigh harms to Great Lakes public trust rights, and did not examine whether Line 5 would keep operating if the tunnel is never built.
The permit at issue was granted in December 2023 for a 4-mile tunnel segment meant to replace the exposed Straits section of the 645-mile pipeline running from Wisconsin to Ontario.
Tribal nations and environmental groups hailed the decision as a major win, while Enbridge said it was disappointed and is weighing legal options as it still seeks remaining state and federal approvals.
The ruling adds uncertainty to a project first pitched in 2018 as a $500 million fix, while the existing 73-year-old pipeline continues operating despite a 2020 shutdown order that remains tied up in court.
Will the court's demand for a broader environmental review ultimately kill the Line 5 tunnel or just prolong the eight-year standoff?
How will regulators balance the protection of sacred Indigenous burial sites against the urgent need to secure a vulnerable energy pipeline?
Michigan Supreme Court Halts Line 5 Tunnel with 6-1 Ruling: What’s Next for Energy, Environment, and Tribal Rights?
Overview
On July 31, 2026, the Michigan Supreme Court voided the Line 5 tunnel permit, siding with Native American tribes and environmental groups who argued that regulators failed to fully consider environmental risks. The court found the Michigan Public Service Commission’s review was too narrow and ordered a comprehensive redo, requiring a broader evaluation of long-term risks and alternatives. This decision creates major delays and uncertainty for the project’s future. Meanwhile, new state permits have sparked further tribal opposition, and the tunnel plan faces challenges over environmental harm, cultural impacts, and the risk of locking in decades of fossil fuel emissions.