In a landmark decision issued July 31, 2026, the Michigan Supreme Court vacated the Michigan Public Service Commission’s authorization of Enbridge’s proposal to route its Line 5 pipeline through a tunnel beneath the Straits of Mackinac.
A coalition of Tribal Nations and environmental groups appealed the Commission’s approval, arguing that the agency failed to address the significant dangers posed by the project to the environment and the public trust in the Great Lakes. Kanji & Katzen represented Flow Water Advocates in an appeal focused on the important public trust issues in the case.
The Michigan Supreme Court agreed with the co-appellants and directed the agency to rigorously evaluate these harms on remand, including the harms to public trust resources such as the fisheries (both tribal treaty and non-Indian fisheries) and navigation, and the significant risk that perpetuation of Line 5’s lifespan through construction of the tunnel will lead to releases elsewhere along the span of the aging pipeline. The significance of this risk was driven home on August 25, 2026, when Line 5 ruptured and released at least 1.3 million gallons of natural gas liquids near Saxon, Wisconsin, just to the east of the Bad River Reservation.
The Michigan Supreme Court’s decision marks a crucial step in protecting the Great Lakes and tribal treaty rights from the threat of Enbridge’s proposed tunnel. It will also have important implications for Michigan environmental law more broadly. The decision confirms that state agencies have a responsibility to safeguard the public trust in their administrative decision making. And it holds that one of the state’s key environmental statutes—the Michigan Environmental Protection Act—requires agencies to engage in a searching analysis of environmental harms caused by a proposed project and to evaluate the project against alternatives in a fair and even-handed way.