BOISE — Proposed changes to Idaho’s domestic water-use exemption would benefit declining aquifers by involving more people in their preservation, according to supporters.

Opponents said Senate Bill 1083 adds regulation but offers little benefit since domestic use is a small percentage of total water use in the state.

The Senate Resources and Environment Committee sent the bill out for amendment at the request of sponsors, who sought changes to some definitions and other language.

Under current law, a water right permit is not required for a domestic well as long as exemption criteria are met. Usage of up to 13,000 gallons a day is allowed for homes, organization camps and public campgrounds, livestock, and for irrigation of up to half an acre.

SB 1083 would allow multiple exempt domestic uses to be combined into a single well — applicable to in-home water use only, according to the bill’s purpose statement. In planned subdivisions in a state-designated groundwater management, critical groundwater or moratorium area, the domestic-use exemption would apply to in-home or stock watering purposes only; other uses including irrigation would require a permit.

The bill would streamline the process to ensure compliance with domestic use exemption requirements. SB 1083 would require that community wells within municipal service areas or areas of impact are compatible with the municipal system, and that surface water is used for irrigation when available.

Construction of many domestic wells has occurred in the past 20 years, Paul Arrington, Idaho Water Users Association executive director and general counsel, said in an interview. And the Idaho Water Resource Board and users continue to spend substantially to optimize water supply.

“We can’t do things the same way we have done them,”  he said. “We see a lot of things happening.”

IWUA and other stakeholders about three years ago started looking at modifying the domestic exemption.

Requiring a shared or public water system in proposed residential subdivisions of 10 or more lots — each less than half an acre — was proposed in a 2024 bill that never got a hearing.

“That proved to be the wrong idea,” deemed cost prohibitive from a development standpoint especially for smaller projects, Arrington said.

The new bill would be “a small step forward to get us in a better place with our water management,” he said.

“This is about parity,” Senate President Pro Tem Kelly Anthon, a bill sponsor, said at the hearing.

During shortages, cities — which must have water rights — have shut down systems even as residential landscape watering continued outside city limits, he said.

“What is the problem this bill is trying to solve?” said Mark Jones, a Twin Falls-based land broker. “We hear about all of these wells coming in, drawing into the aquifer. Where in this bill does it … help save the quality of this aquifer?”

Other comments against the bill included that the existing system works and many domestic well owners don’t come close to using their daily limit, and that irrigation districts already provide input on proposed developments.

The bill is not a “silver bullet,” as domestic wells represent about 2% of total water use in the state, Arrington said. But agriculture at more than 90% is “doing its part.”

In the southwest region, “you think about the amount of flood irrigation that has taken place over the years,” said Braden Jensen of the Idaho Farm Bureau Federation. “And now as that’s being converted into one-home lots, with more straws in the ground, that’s only going to increase water challenges.”

Proliferation of domestic wells has potential to affect water quality, said Shelley Roberts of the Idaho Rural Water Association. She supports the bill.