How Boise's Geothermal System Built In The 1890s Still Serves Much Of Downtown

Apr 28, 2016

On Sunday evening, hot water poured on to the intersection of Grove and 3rd streets in downtown Boise. Steam filled the air as a leak from the city's underground geothermal line brought attention to a system not many people know much about.

One of the plaques on a building in downtown Boise denoting it uses the city's geothermal line. The geothermal water is pumped from its source in the foothills, and heats buildings and water.
Credit City of Boise

Since 1890, 177-degree-water has been pumped from the foothills to heat buildings and provide hot baths. It was the first of its kind in the country, serving Victorian homes on Warm Springs Avenue and hotels in downtown Boise.

These days, the system has made updates, but the basic science and product is the same. Geothermal Coordinator Jon Gunnerson says a lot of familiar buildings in downtown use geothermal energy -- like the YMCA.

"They heat all their pools and showers with the geothermal water, we provide it to the Hampton Inn in BoDo," says Gunnerson. "They're heating all their laundry facilities, pool and space heating. One Capital Center, Idaho Independent Bank, Banner Bank ..."

A bunch of government offices, including City Hall and the Ada County Courthouse, use geothermal energy. Ten Boise State buildings are also on the geothermal line.

But the system is restricted by its nature: Gunnerson says the further away it gets from the source in the foothills, the cooler the water gets. So the likelihood of geothermal energy heating homes on the Bench (or anywhere too far from downtown) is low.

Find Frankie Barnhill on Twitter @FABarnhill

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