An Oil Pipeline is Threatening the Great Lakes

A battle is raging to protect the largest surface freshwater system in the world.

The Great Lakes are a defining cultural and ecological anchor for the Midwest, supplying drinking water for up to 40 million people in the U.S. and Canada. Spanning more than 95,000 miles, these five lakes also make up one of the most diverse watersheds in the world. They also serve as the home to 3,500 species of plants and wildlife and more than 250 species of fish, including many with cultural and traditional importance to tribal nations.

But the Line 5 pipeline puts the Great Lakes — and all it supports — at risk.

What is the Line 5 pipeline?

Line 5 is an oil and gas pipeline that transports up to 23 million gallons of fossil fuels each day through Wisconsin and Michigan to Canada, passing through the middle of the Great Lakes and hundreds of interconnected waters. Since the 1950s, the Canadian oil giant Enbridge has transported toxic fossil fuels through this pipeline. Each year, the amount of oil and gas it carries produces carbon emissions equal to 19 million gas-powered cars once burned.

The pipeline runs through the tribal reservation of the Bad River Band of Lake Superior Chippewa in Wisconsin and the treaty-protected areas for Bay Mills Indian Community in Michigan. Neither of the Tribes were consulted during Line 5’s construction, yet they have lived with its catastrophic risk for decades.

An oil covered bird sits on the side of the Kalamazoo River after an oil spill of approximately 800,000 gallons of crude from the Line 5 pipeline near Marshall, Michigan in 2010. (Michigan Department of Environmental Quality.)

Over its lifespan, Line 5 has leaked more than 1.1 million gallons of oil, polluting important watersheds and surrounding communities. Today, it is operating 20 years past its engineered lifespan, risking malfunction due to corrosion and pressure.

Despite its age and risk to the environment, Enbridge is pushing to extend the life of Line 5, drawing local, national, and international opposition, as well as lawsuits from Tribes represented by Earthjustice.

Why is Line 5 a risk to tribal communities?

Line 5 poses an unacceptable risk of an oil spill in some of the earth’s most culturally sensitive and treasured ecosystems. This includes the Straits of Mackinac, a narrow waterway connecting Lake Michigan and Lake Huron. The Straits hold significance as the site of creation for Tribes who have continued to hunt, fish, and gather medicinal plants there since time immemorial.

Line 5 also threatens the Kakagon-Bad River Sloughs, an internationally important wetland in northern Wisconsin that harbors the region’s largest bed of wild rice, a cultural staple for the area’s Tribes.

Line 5’s dilapidated state is only becoming more dangerous as the pipeline ages. The Bad River Band has warned for years that the naturally widening Bad River in Wisconsin could eventually come dangerously close to Line 5, exposing the pipeline to the river current and increasing the risk of potential collisions with uprooted trees and other debris that could easily puncture the pipeline.

In 2023, these warnings became more urgent after rapid riverbank erosion in the spring brought the Bad River current in Wisconsin within 11 feet of the pipeline. The watershed around the Bad River Band’s Reservation feeds into Lake Superior, so any pollution from the pipeline would flow downstream to the Great Lakes and through the Kakagon-Bad River Sloughs. There is also a risk that pollution from the pipeline’s construction would contaminate groundwater, which would impact the Band’s drinking water.

In June 2026, construction to reroute the Line 5 pipeline around the Bad River Band’s reservation spilled up to 1,900 gallons of drilling fluid into a forested wetland.

A tree falls into the Bad River in Wisconsin on June 1, 2023. Rapid erosion had left the Line 5 oil pipeline just a few yards from being exposed to the powerful current of Wisconsin’s Bad River. (Bad River Band of Lake Superior Chippewa)

How are the Tribes fighting Line 5?

The Bad River Band is fighting to remove the Line 5 oil pipeline from their homeland along Lake Superior. In 2019, the Band sued Enbridge for illegally trespassing on its reservation, a case that is currently before a federal circuit court. To get around the Band, Enbridge proposed re-routing the pipeline. This re-route involves blasting, trenching, and drilling across at least 186 waterways and over a hundred acres of wetlands. This poses risks to the Band’s drinking water and downstream wild rice beds.

The Bay Mills Indian Community and other Tribal Nations have also been fighting since 2020 to stop Enbridge from building a massive, risky underground tunnel to house a replacement section for Line 5 that currently runs in open water through the Straits of Mackinac. Despite evidence of the serious risk of an explosion and oil spill, the Michigan Court of Appeals upheld approval for Enbridge’s tunnel project in 2025. The Tribal Nations and allies have now taken this fight to the Michigan Supreme Court.

Bad River Band Chairman Robert Blanchard answers questions from Earthjustice Senior Attorney Stefanie Tsosie on September 15, 2025 at Northwood Technical College in Ashland, Wisconsin during hearings related to Line 5 permitting. (Derek Montgomery for Earthjustice)

How is Earthjustice fighting for the Great Lakes?

Both of Enbridge’s proposals — a tunnel under the Straits and a new pipeline around the Bad River Band’s reservation — have drawn local, national, and international opposition. Earthjustice is challenging both proposals on behalf of the Tribes:

• The reroute: Earthjustice is representing the Bad River Band in challenging Wisconsin’s permit in state court, and is challenging the U.S. Army Corps’ permit in federal court.

• The tunnel: Alongside the Native American Rights Fund (NARF), we are representing the Bay Mills Indian Community in challenging one of Michigan’s tunnel permits before the Michigan Supreme Court, and in opposing remaining state and federal permits for the project.

Earthjustice is also working to remove and shut down the current pipeline. In 2023, Earthjustice represented a coalition of 63 Tribal Nations from across the Midwest and Canada in an amicus brief supporting Michigan’s Attorney General in a lawsuit to remove the Line 5 pipeline from the heart of the Great Lakes. When the case went before the U.S. Supreme Court, Earthjustice represented ten Tribal nations in an amicus brief urging the Justices to keep the case in the Michigan state court.

In April 2026, the U.S. Supreme Court unanimously blocked Enbridge’s attempt to move the case to federal court.

How can you help?

If Enbridge is allowed to move forward, it will extend the life of Line 5, risking the Great Lakes and increasing our reliance on fossil fuels for another century. Hundreds of thousands of people across the country have already spoken out against Line 5 to preserve the Great Lakes for future generations.  We hope you’ll join the chorus of opposition the next time there’s an opportunity for public comment.

Whitney Gravelle, the president of the Bay Mills Indian Community. (Sarah Rice for Earthjustice)