Dec. 6 (UPI) -- Inclement weather in the narrow waterway separating the two Michigan peninsulas meant Enbridge had to close a major pipeline system, a state agency said.
The National Weather Service has issued a winter storm warning for parts of the region through 5 p.m. local time. Wind gusts as high as 35 miles per hour and snow accumulations of as much as 6 inches are expected. Strong winds are expected to continue at least through Friday.
As part of an agreement with the state, Canadian energy company Enbridge shut down its Line 5 system running through the Straits of Mackinac as a precaution.
"The purpose of the state's agreement with Enbridge was to find practical solutions to concerns we had about the operation of Line 5 and the safety of the Great Lakes," Valerie Brader, executive director of the Michigan Agency for Energy, said in a statement.
Line 5 runs through Michigan's Upper Peninsula, through the turbulent Straits of Mackinac and then east to Ontario. Waves as high as 9 feet were recorded on Tuesday and the agreement with the state says Enbridge has to shut the line down during sustained periods of inclement weather, where wave heights reach more than 8 feet.
Line 5 is part of a broader network of pipelines and can carry as much as 540,000 barrels of oil per day. Asked by UPI about the impact on retail gasoline prices, the Michigan agency said there are no studies related to a short-term closure. Modeling done for Line 5 provisions, from abandoning the pipeline system altogether to building a new one, range from a $2.13 per gallon increase to 1 cent, respectively.
Under agreements with the state, the company needs to conduct a study on the feasibility of building a new system in the Straits of Mackinac and ways to mitigate risk.
In August, the Michigan State Police, Departments of Environmental Quality and Natural Resources, and the Michigan Agency for Energy said they were concerned by gaps in the protective coating on parts of Line 5 in the straits, at least one of which was caused when Enbridge installed new supportive anchors. Recent inspections revealed dozens of gaps across the span of the pipeline.
The broader Lakehead system in the region ruptured in southern Michigan in 2010, leading to the largest inland release in the modern era of the oil industry in the United States