In anticipation of a steep increase in property taxes for the state’s largest utility, NorthWestern Energy, the Montana Public Service Commission (PSC) opened a docket Tuesday in an attempt to mitigate the impact to ratepayers.

NorthWestern Energy recently informed the PSC that the Department of Revenue calculated an approximately 42% increase in the company’s taxable valuation due primarily to the acquisition of 11 hydroelectric dams in 2014. The valuation increase is expected to result in a significantly larger tax bill for NorthWestern Energy, which state law allows to automatically pass through to their customers, a policy that is unique to utilities in the state of Montana.

The commission plans to hold a hearing on NorthWestern’s tax tracker before the taxes are calculated into rates on Jan.1, 2016.