Overview:
The Michigan Supreme Court has overturned a key state permit for Enbridge’s proposed Line 5 tunnel beneath the Straits of Mackinac, ruling that regulators failed to comply with Michigan environmental law and the public trust doctrine. The decision sends the permit back to the Michigan Public Service Commission for further review and marks a significant legal victory for Tribal Nations seeking to protect the Great Lakes and uphold treaty rights.
In a significant victory for Tribal Nations and environmental advocates, the Michigan Supreme Court has overturned a key permit authorizing Enbridge Energy’s proposed Line 5 tunnel beneath the Straits of Mackinac, sending the project back to the Michigan Public Service Commission (MPSC) for a new review.
In its decision, the state’s highest court ruled that the MPSC violated the Michigan Environmental Protection Act (MEPA) and failed to fulfill its obligations under Michigan’s public trust doctrine when it approved Enbridge’s tunnel permit in 2023. The ruling requires the commission to reconsider the application using the legal standards outlined by the court.
The proposed project would relocate a four-mile segment of the Line 5 pipeline into a tunnel beneath the Straits of Mackinac. Enbridge has argued the tunnel would reduce the risk of an oil spill in the Straits, while Tribal Nations and environmental organizations contend the project would prolong the life of an aging pipeline and threaten one of North America’s most ecologically significant freshwater systems.
For the Bay Mills Indian Community and other Tribal Nations, the ruling represents an important affirmation of treaty rights and the state’s responsibility to protect the Great Lakes.
“Today is a reminder that when people stand together with courage and conviction, change is possible,” Bay Mills Indian Community President Whitney Gravelle said. “For years, Tribal Nations, communities, and thousands of people across the country have raised their voices to protect the Great Lakes. This decision gives us another opportunity to honor our treaty rights, protect our waters, and consider the generations who will inherit this place.
“The Straits of Mackinac are not simply a route for an oil pipeline to be abused. They are sacred waters, the heart of creation for Anishinaabe people, and a source of life for millions. Some things are simply too sacred to be buried beneath a tunnel. Our work continues, and we remain committed to protecting the Great Lakes for generations to come.”
The Bay Mills Indian Community was joined in the legal challenge by the Little Traverse Bay Bands of Odawa Indians, the Grand Traverse Band of Ottawa and Chippewa Indians, and the Nottawaseppi Huron Band of the Potawatomi. The Tribal Nations were represented by Earthjustice and the Native American Rights Fund. The Michigan Climate Action Network and the Environmental Law & Policy Center also presented separate legal arguments before the Michigan Supreme Court.
Earthjustice Senior Attorney Adam Ratchenski said the ruling reinforces longstanding protections under Michigan environmental law.
“This ruling is an inspiring victory for Tribes, environmental advocates, and everyday people who’ve joined hands in the fight to stop the dangerous Line 5 tunnel project,” Ratchenski said. “The Court’s decision upholds the bedrock principles of Michigan environmental law. Enbridge’s application to build the tunnel now heads back to the Michigan Public Service Commission, where we will be prepared with robust arguments in defense of Tribal rights and the Great Lakes.”
Opponents of the project note that Enbridge’s proposal to place a hazardous liquids pipeline inside a tunnel beneath the Straits would be unprecedented. Construction of the tunnel is expected to take more than six years and would occur beneath waters that hold deep cultural and spiritual significance for the Anishinaabe.
“Whether Line 5 is suspended in the water or encased in a tunnel, it is simply a terrible idea to pump more than half a million barrels of oil every day through the middle of the Great Lakes,” said Native American Rights Fund Managing Attorney David Gover. “There is a brighter future on the horizon. We can get oil out of the Great Lakes, protect Tribal sovereignty, and preserve our freshwater for generations to come.”
The decision marks the latest legal setback for Enbridge’s Line 5 project, which continues to face challenges in both state and federal courts. While the ruling does not permanently halt the tunnel proposal, it requires the Michigan Public Service Commission to reconsider the permit under a more rigorous environmental review, providing Tribal Nations another opportunity to argue that the project should not move forward.
