NorthWestern Energy says it has received notice that Susteen Inc. will not lease the original powerhouse at Rainbow Dam for a databank center, and now the company will demolish the old building.
NorthWestern Energy and PPL Montana worked for almost a decade, along with the Cascade County Historical Preservation Old Rainbow Powerhouse Repurposing Committee, to look for alternative uses for the original powerhouse on the Missouri River in Montana.
Construction on the 80-foot-wide and 326-foot-long original Rainbow Powerhouse began in 1909 and was completed in 1910, along with the dam and the power line. Electricity was first transmitted to Butte in 1910. PPL Montana commissioned a new, more efficient 60-MW powerhouse at Rainbow Dam in 2013.
NorthWestern Energy bought the Rainbow hydro facility in 2014 and committed to continue working with the committee to look for alternative uses for the original powerhouse, including providing $50,000 for a feasibility study for alternative uses.
“This remarkable effort by all involved to diligently explore potential uses and especially this possibility with Susteen was truly impressive,” said NorthWestern Energy Director of Environmental and Lands Permitting and Compliance Mary Gail Sullivan. “Unfortunately, the plan will not move forward.”
With the news that Susteen would not be leasing the building, NorthWestern Energy notified the Federal Energy Regulatory Commission that the company intends to proceed with a plan to raze the original Rainbow Powerhouse. Demolition of the facility is expected to begin this fall.
NorthWestern Energy will work with the Cascade County Historical Preservation Old Rainbow Powerhouse Repurposing Committee and others to find ways to use elements of the powerhouse for a historical interpretive display in Cascade County.
“Every possibility to repurpose the facility has been explored,” Sullivan said. “The challenges, which include safety and security restrictions because of the facility’s remoteness and location on the Missouri River and being onsite with an active hydro operation, limited the type of project that could potentially use the building.”
NorthWestern provides electricity and/or natural gas to about 734,800 customers in Montana, South Dakota and Nebraska.