DNR Starts Contingency Water Pumping at Canisteo Mine Pit

Map of Canisteo Mine Pit water pumping and flow path (Credit: Minnesota DNR)

The Minnesota Department of Natural Resources has started contingency pumping at the Canisteo Legacy Mine Pit near Bovey to keep water levels below 1,318 feet for the protection of local community infrastructure.

The pumping will cause Canisteo water levels to drop, creating a gap between winter ice cover and the unfrozen water surface, resulting in unsafe ice conditions across the entire pit. Water from the Canisteo Mine Pit is flowing into nearby wetlands and Holman Lake in Itasca County, potentially causing unsafe ice conditions on those water bodies as well.

“The DNR started pumping water from the Canisteo Pit on Friday [Dec. 30], and that pumping is going to create unsafe ice conditions on the Canisteo Pit, Holman lake, and the wetlands in between the lake and pit,” said Erika Herr, DNR Mine Permitting & Coordination Supervisor. “And so the DNR is urging people to stay off those water bodies this whole winter through spring while the pumping is occurring, just because of the unsafe ice.”

Winter pumping at the Canisteo Mine Pit will ensure the drain tile system in the city of Bovey will continue to divert groundwater away from residential structures. The pumping system is drawing water from the pit at a maximum rate of 11,000 gallons per minute.

Graph of Canisteo Mine Pit water levels since 1990 (Credit: Minnesota DNR)

The DNR planned to begin pumping on Oct. 1 but deferred this when DNR invasive species specialists discovered zebra mussels in the pit water in September.

“We have to make sure that we don’t transfer those zebra mussels downstream, so in the wintertime those zebra mussels fall out of the water column, and then we’re able to pump downstream at that time because they’ll no longer be in the water column,” said Michael Liljegren, DNR Lands and Minerals Assistant Director.

Veligers like zebra mussels drop out of the water column when water temperatures are below 53 degrees.

According to the DNR, mining in the Canisteo stopped in 1980, and there is no company responsible for managing its rising water levels. As of Dec. 2022, the Canisteo’s water level was at approximately 1,311 feet, which is 13 feet below natural overflow levels.

With $710,000 from the Department of Iron Range Resources & Rehabilition, contingency pumping at the Canisteo is a short-term solution to prevent water from overtopping the pit. A permanent solution will require legislative funding.