700+ miles of Great Lakes shoreline potentially vulnerable to Enbridge Line 5 oil spills

Enbridge Line 5 oil spill graphic

More than 700 miles of pristine Michigan shoreline is vulnerable to an oil spill from the Enbridge Line 5 pipeline under the Straights of Mackinac. A study released by the U-M Water Center modeled 840 simulations of potential leaks to map out the high risk shorelines of Lake Huron, Lake Michigan, and their islands.

U-M hydrodynamics expert David Schwab authored the study, which was supported by  the National Wildlife Federation. According to the study, “when all 840 simulated spills are plotted on a map, a total of 720 miles (1,162 km) of shoreline in the U.S. and Canada are considered potentially vulnerable to spills that would require cleanup. Seven hundred twenty miles is roughly the distance from Detroit to Atlanta.

Schwab and colleague Eric Anderson of the National Oceanic and Atmospheric Administration’s Great Lakes Environmental Research Laboratory developed a high-resolution hydrodynamic model that utilized weather and water-current data measured taken during the ice-free season.

Key Findings

  • Nearly 60 percent of Lake Huron’s open water and more than 15 percent of Lake Michigan’s open water showed visible oil in at least one of the 840 spill simulations. The total area of those vulnerable open waters—17,318 square miles (44,405 square km)—is roughly equivalent to the combined surface areas of lakes Erie and Ontario.
  • The maximum open-water area covered by a single hypothetical spill is 624 square miles (1,600 square km), an area larger than Lake St. Clair.
  • The shortest arrival times for visible surface oil—2.5 hours—occur on the south shore of the straits, near Mackinaw City. Mackinac Island could be impacted in nine hours, Bois Blanc Island in 10 hours. Oil could reach Cheboygan in 30 hours.

For more information, see the full study release.

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