RATHDRUM — Avista Utilities is preparing a Rathdrum site it owns for a possible natural gas generating facility.

The Rathdrum City Council last week approved Avista's request to change the city's zoning map for 302 acres at the site on the west side of the city between Idaho and Greensferry roads and southeast of Burlington Road from industrial, open space and public to industrial.

Debbie Simock, Avista spokeswoman, said while the utility purchased the site and obtained the zone change, construction is still not imminent.

"Purchasing and optioning land is part of our normal course of business," she said.

Simock said the company won't know for sure if it will construct a plant on its own or purchase power from a third party there until it goes out for a request for proposal in 2018 or 2019.

"We'll just have to look at what options are available in the market and best meet the needs of our customers at that time," she said. "That land is a good place to site another plant if that is the outcome. That's why we applied for the re-zone."

Rathdrum is a prime spot for a future facility because a natural gas pipeline and Avista's electric transmission lines are in the city, making it a cost-effective area for a natural gas generating facility.

Avista's 2015 electric plan shows a need for electric generation by the end of 2020 to meet projected customer demand. To meet the demand, the plan recommends investing in a natural gas-fired combustion turbine similar to others in the utility's system. Purchasing the property in Rathdrum was a step toward meeting that demand, Simock said.

Simock said developing, designing, permitting and constructing any new generating facility takes time, so purchasing the site and obtaining the zone change sets Avista up better to meet future customer demand.

When the property was originally annexed into the city, it had an industrial zoning. When the Merritt Brothers development firm purchased it, zoning was changed to mixed uses. Avista then bought it and changed the zoning back to industrial.

"It's on the part of town where we don't have much infrastructure, so somebody would have to make a large commitment to put water and sewer out there," Rathdrum Mayor Vic Holmes said.

Avista is planning to build a fossil fuel generating facility rather than another type because it can be turned on or off when needed to meet customer demand.

"Because the wind does not always blow or the sun does not always shine, wind or solar are not dependable," a project description states. "This is especially true during extreme winter or summer temperatures. Wind or solar can't be counted on to meet demand during peak periods."

Simock said if Avista constructs its own plant at the site, it would likely raise rates, but it's too early to tell how much.

Avista will explore its water supply needs for the property as part of feasibility studies for a natural gas generating facility.

Brian Walker can be reached at bwalker@cdapress.com or @brianCDAPress.