1. Mitigation plan

Allocating groundwater over four years instead of a single growing season is a key feature of the proposed Eastern Snake River Plain Aquifer mitigation plan and better reflects how farms operate, according to proponents.

Under the proposal, which includes four-year usage averaging, “we are able to mitigate in a way that is much more flexible,” said Adam Young, who farms near Blackfoot, Idaho, using groundwater to irrigate.

Groundwater users and a coalition of surface water users with senior water rights are expected to approve the new plan by mid-November.

The mitigation plan would replace a 2015 settlement agreement and this year’s temporary pact struck following a state Department of Water Resources curtailment order.

The updated plan “puts our best ideas together, outlining a path forward that follows Idaho law, keeps our agriculture industry flourishing and supports the health of the ESPA,” Lt. Gov. Scott Bedke, an Oakley rancher, said in a statement after speaking to an interim legislative committee on natural resources Oct. 28.

Using a four-year allocation enables farmers to save water for potentially dry seasons — such as by returning more into the aquifer via recharge operations in a high-snowpack year — and provides for some flexibility in crop mix, said Bob Turner, Idaho Groundwater Appropriators executive director.

Basing allocations on a four-year period “allows us to maximize conservation efforts in the years we can,” Young said. And if a district uses less than its allocated volume, the balance can be carried to the next four-year period.

Groundwater districts that develop conservation projects that benefit a key area or many users may qualify for increased credit toward compliance, Idaho Water Resource Board chairman Jeff Raybould told the committee.

A four-year period also applies to mitigation. Under the current agreement, junior water right holders must deliver 50,000 acre-feet of water whether or not the senior right holders need it. Under the new plan, the juniors would deliver the volume needed up to 75,000 acre-feet.

The 75,000-acre-foot target will be reevaluated after two years to reflect aquifer and Snake River metrics, particularly in the critical Blackfoot-to-Minidoka reach, Raybould said.

“If that 75,000 acre-feet is adequate and the reach gains don’t go down, it will remain 75,000 acre-feet for the third year of this first four-year block of the agreement,” he said. Subsequently, parties “will agree on what that number should be, up or down” based on conditions and needs.

Groundwater users need the ability to deliver up to that volume, such as by acquiring options to lease reservoir water.

Measuring groundwater usage each month during the growing season is another component of the proposal. The system will need fine-tuning over time, but the idea is to find and address changes as soon as possible, said Bedke and Raybould, who mediated the negotiations.

“Everyone benefits when we talk farmer-to-farmer to find a solution,” Bedke said in the statement.