Avista Utilities is seeking a two-year rate hike for its electric and natural gas customers in North Idaho to pay for replacing or upgrading infrastructure.

If approved by the Idaho Public Utilities Commission, it would mean a $7.03 increase in the monthly bill for a residential electric customer using an average of 910 kilowatt hours from $86.39 to $93.42 starting Jan. 1, 2018. On Jan. 1, 2019, that customer’s monthly bill would climb $4.02 to $97.44.

Residential natural gas customers using an average of 61 therms per month would see an increase of $3.37 per month in 2018, taking their bill from $51.10 to $54.47, and a $2.07 increase in 2019 to $56.54.

"Our customers expect their energy to be there when they need it, and so do we," Avista Chairman, President and Chief Executive Officer Scott L. Morris said. "To meet these expectations, we’re continually investing in our systems in an effort to maintain reliability and deliver value, at a reasonable cost for customers."

The IPUC, which has up to nine months to review Avista's request, will announce dates for customer workshops, hearings and written comment deadlines in the near future. Avista's application can be seen at www.puc.idaho.gov. Click on "Open Cases" under the "Electric" or "Natural Gas" heading and scroll down to Case No. AVU-E-17-01 or AVU-G-17-01.

Avista officials said the request is driven by ongoing investments in its plants, technology and other assets as well as increased costs associated with providing power to about 128,200 Idahoans in its service territory.

The projects include rehabilitation and maintenance of the Kettle Falls electric generating facility that provides electricity for Idaho and Washington customers. The $6.3 million project would rewind the 30-plus-year-old generator that is at the end of its expected life.

About $17.5 million in substation rebuilds are planned in 2017 and $8 million in 2018. Substations in Priest River and Kamiah are among those proposed to be rebuilt because they have reached the end of their useful lives.

Several transmission projects totaling $25 million over the next two years required to comply with federal standards are also planned, including the Coeur d'Alene to Pine Creek line.

"The failure to timely replace aging transmission infrastructure will subject our customers to the increased risk of service outages and increased restoration costs ...," an Avista press release states.

Avista also plans to remove and replace natural gas lines that are more than 30 years old throughout its service territory.

Most of the costs associated with the new South Channel Dam at Post Falls were included in Avista's 2016 general rate case and are included in customers’ rates today.

The company is also proposing increases to the basic monthly charge for residential electric and natural gas. The charges for both are proposed to be $6 per month. The current electric basic charge is $5.75 and natural gas $5.25.