RED LODGE — Thousands of gallons of water continue to flood into a Red Lodge home after a drain inside a nearby abandoned mine failed, according to the city's public works department.
In early-July, the Montana Department of Environmental Quality (DEQ) was alerted that water at an estimated rate of 100 gallons per minute was entering into the basement of a property located at 221 Grant Ave. S. in central Red Lodge. The property backs up to a hill, on top of which sits the Red Lodge airport to the west.
A public works investigation indicated the gravity drain that previously carried spring water from within the workings of the abandoned Sunset Mine to the city’s stormwater system has failed.
Testing showed the floodwater’s pH was neutral, indicating spring water that does not pose a threat to human health.
Dewatering pumps and gravity flow are currently helping drain the basement and garage of the home into a city sewer drain.
In addition to the flooding of the Grant Street property, responding personnel are concerned the water pressure continues to build behind the mine bulkhead adjacent to the property, which could result in failure and presents a safety concern.
DEQ, its contractor Olympus Technical Services, and Red Lodge Public Works are prioritizing decreasing the head pressure to prevent further failure and structure damage.
The plan to address rising groundwater levels is to excavate into the mine workings to install a temporary drain that will relieve pressure by dewatering the mine. This work has already begun.
Adjacent to the flooding property to the north is a concrete bulkhead labeled, “Sunset Mine June 23 1907.” The Sunset Mine was initially developed around 1901 and later acquired by the Northwestern Improvement Company in 1907. Mining was conducted steadily until a downturn in the late 1920s. The company stopped mining completely in 1932.
Historic documents note that water was a constant problem in the west side mines, located immediately adjacent to the present-day property experiencing flooding.
