Overview

• The court accepted two appeals targeting the Michigan Public Service Commission’s 2023 permit, one from a coalition including the Bay Mills Indian Community, Grand Traverse Band, Little Traverse Bay Bands, and Nottawaseppi Huron Band, and a separate case from Flow Water Advocates.
• Justices requested arguments on whether the Michigan Court of Appeals gave excessive deference to the commission and whether evidence on spill risks along the entire pipeline was improperly excluded.
• A second order asks whether the commission was required to apply Michigan’s public trust doctrine, with the state bar’s environmental and property law sections invited to file briefs.
• Line 5’s tunnel proposal would relocate the Straits crossing into a roughly 3.4–3.6-mile concrete-lined tunnel, replacing the exposed dual pipelines that critics say pose spill risks.
• Key approvals remain outstanding, including an EGLE water-resources permit redo and U.S. Army Corps review under a narrowed scope, with the Corps indicating a final federal decision is expected this fall.