The US Army Corps of Engineers has officially authorized the construction of the controversial Line 5 tunnel project in the Straits of Mackinac. The project, which is designed to divert a section of the existing petroleum pipeline from the open waters of the Straits into a concrete tunnel beneath the lakebed, was deemed by the Corps to be not contrary to the public interest. In its announcement, the agency further stated that the project would not harm tribal treaty rights.
Despite granting the permit, the Corps acknowledged that the project would have adverse effects on endangered species and archaeological sites. The agency noted that the construction would contribute to long-term impacts of habitat loss and have long-term detrimental impacts on land use. Specifically, the Corps identified that the project would likely adversely affect Houghton’s goldenrod and dwarf lake iris, which are listed as threatened species under the federal Endangered Species Act. However, the agency concluded that it does not expect reductions in the overall recovery, numbers, or distribution of these species following mitigation efforts.
The project site is considered culturally and spiritually significant to the Anishinaabe tribal nations. The Corps noted that there would be major, permanent, adverse effects on historic properties, including archaeological sites, which the tribal nations have stated cannot be mitigated. A coalition of Native American tribes that has opposed the project strongly criticized the decision. David Gover, managing attorney with the Native American Rights Fund, stated that the federal government has a solemn obligation to uphold and protect treaty rights and is supposed to protect American waters and sacred spaces. He argued that the U.S. Army Corps instead rubber-stamped a Canadian oil project that desecrates a tribal sacred space and threatens to pollute the Great Lakes.
Enbridge Energy, the owner of the pipeline, praised the decision. In a written statement, the company said the federal permit represents the highest standard of environmental review required for major critical energy and other infrastructure projects. Enbridge maintained that Line 5 is safe and that the company will continue operating the pipeline responsibly, incorporating enhanced safety measures in the Straits while protecting Michigan’s natural and cultural resources.
The Corps’ decision aligns with the Trump administration’s goal of bolstering fossil fuel energy and preventing renewable energy development. Adam Telle, Assistant Secretary of the Army for Civil Works, said in an emailed statement that the approval is a testament to President Trump’s vision to ensure the nation’s energy dominance. He added that by cutting unneeded red tape and overhauling the regulatory process to provide fast, clear, and consistent decisions, the administration is helping projects like this move forward with regulatory certainty.
David Holtz, coalition coordinator for the group Oil & Water Don’t Mix, said in an email that the decision was driven by the Trump administration’s phony national energy emergency. He noted that the decision failed to consider what would happen if the tunnel was not built and the pipeline was decommissioned. Holtz compared this to the Michigan Public Service Commission’s permit review, which the Michigan Supreme Court recently ruled was erroneous. The court had criticized that review for being overly narrow, failing to consider potential harm to public rights to the Great Lakes, and failing to study whether Line 5 would shut down if the tunnel is not built.
While the federal approval clears a significant hurdle for the nearly decade-old proposal, construction is not expected to begin immediately. The project remains tied up in state and federal court, and opponents have promised new lawsuits. On July 15, Michigan’s departments of Natural Resources and Environment, Great Lakes and Energy issued two key permits for the project, despite noting disruption to Native American burial sites and harm to wetlands and rare species. Enbridge is also seeking a permit to discharge millions of gallons of treated wastewater per day into Lake Michigan during construction, with a ruling from EGLE expected by September 30.
Meanwhile, the state is battling in court with Enbridge over Governor Gretchen Whitmer’s 2020 order to shut the existing pipeline down due to concerns over a potential oil spill in the Straits. Although a federal judge ruled in December that Michigan had no authority to order a shutdown, the state has appealed. Additionally, Michigan Attorney General Dana Nessel has sought a shutdown since 2019 in a separate case that has moved between state and federal courts. That case is currently paused in the 30th Circuit Court in Ingham County pending the resolution of the litigation surrounding the governor’s shutdown order.
