A mine-pit lake on the Iron Range nearing overflow to get a temporary fix

A lake in a former iron mine pit is about to overflow, threatening to flood the city of Bovey, Minn., and other Iron Range communities in the next few years.

On Monday, the Iron Range Resources and Rehabilitation Board (IRRR) approved $710,000 for a temporary solution — mechanically pumping water out of the Canisteo Mine Pit — while reiterating the need for a permanent outlet.

The water is only 13 feet from reaching the top of the 300-foot-deep Canisteo Mine Pit that stretches north of the cities of Coleraine, Bovey and Taconite.

"It's getting to the point where we need to start pumping by Oct. 1 or we could have some catastrophic things happen, possibly," said IRRR Commissioner Mark Phillips. "We're counting on [the Legislature] to act in the future."

The natural overflow for the pit sits just above Bovey and could spill as soon as 2024, according to the Minnesota Department of Natural Resources.

Last year, Minnesota legislation failed that would've set aside $6.35 million to construct an engineered outlet for the pit. The funds also would have covered maintenance costs for 40 years. Construction will take about a year to complete if funding comes through.

"Prioritizing funding and resources to complete this project is crucial as it mitigates the imminent threat to public safety, property and water quality from the rising Canisteo water level," the DNR wrote in an update to the Legislature last fall.

Locals have been sounding alarms about the impending deluge for decades. In 2004, a Bovey City Council member and business owner, the late Bob Berghammer, told the Star Tribune: "This is a major disaster waiting to happen."

For the temporary pumping approved Monday, water will be routed from the east end of the pit into Holman Lake at the rate of 7,000 gallons per minute. It is expected to be built and operational by October.

Mining began in the Canisteo Pit in 1907 and ceased around 1986. The DNR has been tracking water levels in the 1,300-acre pit since. The agency installed drain tile in Bovey in 2011 to deal with a rising water table as the pit's water levels reached their highest on record.

From 2012 to 2016, Magnetation Inc. pumped water from the pit for its operations before entering bankruptcy. ERP Iron Ore LLC resumed pumping from 2017 to 2018 before its own bankruptcy.

"Our contingency plan was to go back to that route, because we know it can be done," said Mike Liljegren, assistant director of the DNR's lands and minerals division.

Water in the Canisteo Pit has been rising an average of 5 to 7 feet per year.

"While this area may still be a viable option for future mining operations, which may include pumping water from the pit, an engineered outlet structure is the only guaranteed method to control water levels," the DNR says.

The Hill Annex Mine Pit north of Calumet is also in need of an engineered outlet to prevent an overflow as soon as 2028, according to the DNR.