TOPSHOT – Sections of the Enbridge Line 3 pipeline are seen on the construction site near La Salle Lake State Park in Solway, Minnesota on August 7, 2021. Climate activists and Anishinaabe tribal community members are taking 2 weeks to walk to the Minnesota State Capitol Building to raise awareness for water rights and to rally against Line 3, a proposed pipeline expansion to bringing tar sands from Alberta, Canada to Superior, Wisconsin. (Photo by Kerem Yucel / AFP) (Photo by KEREM YUCEL/AFP via Getty Images)
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On Friday, July 31, 2026 the Michigan Supreme Court vacated a key permit for the tunnel project that allows Canadian pipeline company Enbridge to traverse its Line 5 Pipeline through the Straits of Mackinac between the Upper and Lower Peninsulas of Michigan. The ruling throws the project back into limbo, as the Michigan Public Service Commission now must redo its analysis, further delaying a process that began in 2018. (Source).
In a 6-1 ruling, the Michigan Court, per Justice Elizabeth Welch, stated that …”(t)o accurately assess the environmental consequences of the Replacement Project, the PSC should have determined whether the project would be the proximate cause of Line 5’s continued operation and its alleged attendant harms.”
Line 5, which is 73 years old, runs from Superior, Wisconsin, down through Michigan and into Ontario, ending at the refineries in Sarnia, Ontario. In response to growing concerns that the pipeline needed to be modernized, especially in the freshwaters of the Straits of Mackinac, Enbridge reached an agreement with then Michigan Governor Rick Snyder on its modernization. When Democrat Gretchen Whitmer replaced Rick Snyder in 2019, she sought to shut down the pipeline entirely, which among other things may violate the 1977 Canada-United States Transit Pipelines Treaty governing uninterrupted transmission of hydrocarbons between the two nations. (Source).
The attempt by Governor Whitmer to shut the pipeline down entirely has led to contentious litigation now both in Federal Appellate Court in Michigan and in Michigan State Court. Also on July 31, both the federal governments of the United States and Canada asked the court to block any attempt by Michigan to shut the pipeline down. This continues another part of this drama that goes back to the early days of the Whitmer Administration when her State Attorney General, Dana Nessel, filed a lawsuit in Michigan state court seeking closure of the pipeline. In April 2006 the United States Supreme Court ruled unanimously that the federal government had waited too long to try to transfer the lawsuit to federal court, returning the matter to Michigan state jurisdiction. (Source).
As if all of this wasn’t enough, on July 30, 2026 the U.S. Court of Appeals for the Seventh Circuit upheld a ruling that Enbridge trespassed on the Bad River Bend of Lake Superior Chippewa’s reservation in northern Wisconsin and ordered the pipeline rerouted. (Source).
The Court ruled that easements permitting the location of Line 5 across Tribal lands expired in 2013 and Enbridge in effect has been trespassing since.
Built in 1953, Line 5 transports up to 540,000 barrels of crude oil and natural gas liquids. It also is a critical conduit for jet fuel for airports such as Detroit Wayne County and Toronto’s Lester Pearson International Airport. As this drama plays out in all of its forms, the one thing that absolutely is clear is that the pipeline is not getting any younger.