The Idaho Water Resource Board stopped outflows from Milner Dam Feb. 8, a week earlier than planned, due in part to below-normal snowpack.

The move aims to make that water available to recharge the aquifer that runs underneath much of the state’s south-central and southeastern region.

“The early indications are that this year could be on the dry side,” said Wesley Hipke, the board’s Eastern Snake Plain Aquifer recharge manager. “It always could turn around with the weather, but you never know. With current conditions, the board wants to recharge as much as they can.”

The Water Resource Board aims to return an average of 250,000 acre-feet of water annually to the aquifer, per Idaho Legislature guidance. Recharge volume has exceeded that target in each of the past four years. Drought, usage patterns and irrigation are among the factors in declines over recent decades.

The board in late November approved Milner outflow of 200 cubic feet per second Dec. 1-Feb. 15, keeping that water in the Snake River for power production and other uses rather than diverting it at or above the dam for recharge. Streamflow of 1 cfs equals about 2 acre-feet per day.

The original resolution called for Idaho Power Co. to compensate the board in part if the annual recharge goal was not reached; the utility would provide replacement water from its right at American Falls Reservoir upstream.

But by stopping the agreement early, the board will forego having Idaho Power provide compensation if the recharge target is not reached, Hipke said.

Idaho Power agreed to the early discontinuation “in an effort to work with IWRB to meet the 2020-21 recharge goal,” Kresta Davis, the company’s water resources and policy senior manager, told Capital Press.

The one-year resolution and subsequent coordination between the Water Resource Board and company “is the start of an effort that demonstrates a balance between the benefits of hydropower to meet wintertime demands for Idaho Power customers and the need to improve the health and sustainability of the Eastern Snake Plain Aquifer,” she said. “We look forward to ongoing coordination and cooperation with the board as we work toward a long-term solution.”

Company officials in earlier discussions told the board that allowing some water to flow past Milner in winter would be valuable to hydropower production. The company has reduced its dependency on coal generation.

Snowpack recently has been around three-quarters of normal in much of south-central Idaho.

Managing for the various beneficial uses of Snake River water “really takes constant work and cooperation with all of the groups,” Hipke said. “It is not simple.”