Climate change could spike water bills in U.S. cities, according to a new study, and Idaho water experts say this could happen in the Gem State too.

The report, published in Nature Sustainability, focuses on Santa Cruz, California. It finds infrastructure upgrades to maintain water availability due to climate change could double water bills by the middle of the century.

Tyler Fortunati — drinking water bureau chief with the Idaho Department of Environmental Quality — said drought, low snowpack, and depleted aquifers all stand to raise water costs.

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"That can drive systems into having to find alternative sources to procure the water, which could cost ratepayers on that system some additional monthly fees to go through those projects," Fortunati said.

Fortunati added this could affect smaller communities even more, with smaller customer bases to absorb the costs.

The Nature Sustainability study shows water rates have risen three times faster than U.S. inflation over the past two decades. It also notes if historical trends continue, more than a third of the nation's households could face unaffordable water costs within the next decade.

MaryAnna Peavey, grants and loans bureau chief with the Idaho Department of Environmental Quality, agreed that water utilities are facing climate change impacts. Peavey said other factors are in play, however, including aging infrastructure and population growth.

That growth puts more demands on drinking water systems, which may need upgrades like building a reservoir or adding a new well or storage tank.

"Those are indications of where you can look at where population growth could have driven that, and some aspects of climate change could have driven that as well," Peavey said.

Peavey emphasized gaps in infrastructure funding are huge. Peavey’s department offers low-interest loans to help lower project costs.

It had more than $247 million in loan requests on the drinking water side last year, and only $87 million available to fund them. Peavey said the gap is even bigger for wastewater systems, with $558 million in requests — and only 10% of that in the budget.

Peavey said she hopes Congress will increase funding for water infrastructure needs.

"With these communities, having some relief of knowing exactly where they're going to get the funds in order to address these upgrades, is a first step on helping minimize costs," Peavey said.

Peavey contributed to a 2025 report from the Environmental Financial Advisory Board, which found that local ratepayers foot the bill for 95% of water infrastructure, with federal spending dropping substantially since the 1970s.