A state district court judge upheld Idaho Department of Water Resources Director Gary Spackman’s designation of a groundwater management area for the Eastern Snake Plain Aquifer.

The Nov. 6 decision by Judge Eric J. Wildman, if not appealed to the state Supreme Court and overturned, means the department can start setting up a groundwater management area and plan, and potentially an advisory committee.

Idaho Ground Water Appropriators Inc. Executive Director Lynn Tominaga said potential issues include water districts having to comply with additional requirements, how any administrative rules would affect groundwater users, and how much representation groundwater and surface-water users have on an advisory committee.

The aquifer runs beneath and next to the Snake River in much of eastern and south-central Idaho. Drought, greater usage, and reduced returns from more efficient irrigation contributed to decades of decline.

A 2016 state-approved settlement between groundwater users and a coalition of surface-water users with senior rights aims to raise the overall aquifer eight to 10 feet over the next 10 years. It requires groundwater users to reduce usage or return to the aquifer 12% of their annual water usage. It provides a safe harbor for groundwater users to keep raising crops without fear of administrative curtailment.

The Idaho Water Resource Board separately committed to annual aquifer-recharge minimums of 250,000 acre-feet.

“Between 5-10% of small groundwater users on the ESPA are not participating in the recovery of the aquifer,” Tominaga said. Having a groundwater management area “allows the director to have those small gorundwater users participate in the recovery of the Eastern Snake Plain Aquifer.”

He said IGWA supports the Water Resources director creating the management area, “but we are anxious to see what he comes out with” in detail.

The 1951 Idaho Ground Water Act authorizes the IDWR director to manage groundwater, and to designate groundwater management areas where all or part of a basin lacks sufficient supply for irrigation or other uses. Spackman on Nov. 2, 2016, issued an order designating a management area for the Eastern Snake Plain Aquifer.

Judge Wildman affirmed the director’s decision that the law does not require an administrative hearing to be held before a groundwater management area is designated.

The judge rejected petitioners’ arguments that the state’s conjunctive-management rules, which treat groundwater and surface water as one system, mean the designation cannot be made.

Wildman affirmed the director was not required to start an administrative rule-making process before designating the groundwater management area, that petitioners were not deprived due process, and that their water rights weren’t deprived or prejudiced.

Petitioners are Basin 33 Water Users and Upper Valley Water Users coalitions. Intervenors include 15 cities, Idaho Ground Water Appropriators, South Valley Ground Water District, Idaho Power, Clear Springs Foods and Snake River Storage.

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