Canada's embassy in Washington says it is "extremely concerned'' about the fate of the Line 5 cross-border pipeline.
A court hearing Thursday in Wisconsin could determine whether the pipeline, owned and operated by Enbridge Inc., is allowed to continue operating.
“The energy security of both Canada and the United States would be directly impacted by a Line 5 closure,'' the embassy said in a statement.
“At a time of heightened concern over energy security and supply, including during the energy transition, maintaining and protecting existing infrastructure should be a top priority.''
The Bad River Band of Lake Superior Chippewa says spring flooding has heightened the risk of a rupture and it wants a federal judge to shut the line down.
A strongly worded statement from the embassy says doing so would endanger more than 33,000 U.S. jobs and US$20 billion in economic activity.
Canada argues that Line 5 is a vital energy conduit across the U.S. Midwest and an economic lifeline for Alberta, Saskatchewan, Ontario and Quebec.
The Indigenous band fears a rupture would foul not only a key watershed on its territory, but also the waters of Lake Superior.
Canada has already invoked a 1977 pipelines treaty with the U.S. in both Wisconsin and Michigan, where Michigan's attorney general is also in court trying to get the pipeline shut down.
Talks under that treaty have been ongoing for months, with the latest session taking place last month in Washington.
“Canada invoked the treaty's dispute settlement provisions because actions to close Line 5 represent a violation of Canada's rights under the treaty to an uninterrupted flow of hydrocarbons in transit,'' the embassy said.
“If a shutdown were ordered because of this specific, temporary flood situation, Canada expects the United States to comply with its obligations under the 1977 Transit Pipelines Treaty, including the expeditious restoration of normal pipeline operations.''
Spring flooding has washed away significant portions of the riverbank where Line 5 intersects Wisconsin's Bad River, a meandering, 120-kilometre course through Indigenous territory that feeds Lake Superior and a complex network of ecologically delicate wetlands.
The band has been in court with Enbridge since 2019 to compel the pipeline's owner and operator to reroute Line 5 around its traditional territory – something the company has already agreed to do.
But the flooding has turned a theoretical risk into a very real one, the band argued in an emergency motion last week, and wants the pipeline closed off immediately to prevent catastrophe.
``There can be little doubt now that the small amount of remaining bank could be eroded and the pipeline undermined and breached in short order,'' the band's lawyers argued.
“Very little margin for error remains.''
Line 5 meets the river on Indigenous territory just past a location the court has come to know as the ``meander,'' where the riverbed snakes back and forth multiple times, separated from itself only by several metres of forest and the pipeline.
At four locations, the river was less than 4.6 metres from the pipeline – just 3.4 metres in one spot – and the erosion has continued in recent days at an “alarming'' rate, the motion said.
In one case, so-called “monuments'' installed to measure the losses show that where there was more than 10 metres of riverbank in early April before the flooding began, only 3.7 metres remained as of last Tuesday.
“Significant erosion is continuing as of the filing of this motion, and the evidence strongly suggests that further bank loss could be substantial and result in exposure and rupture of the pipeline.''
Wisconsin district court Judge William Conley will hear oral arguments on the motion Thursday. It's not clear when he'll decide whether to grant an injunction that would require Enbridge to shut down the pipeline and purge its contents.
Enbridge has described the motion as “truly outrageous'' and unnecessary: “There is no pipeline safety issue and certainly no cause for alarm.''
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