Idaho groundwater users gamble on wet winter

Published online: Jan 05, 2014
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BOISE, Idaho-The state's groundwater irrigators are banking on a wet winter and may face widespread future curtailment if it doesn't materialize.

Idaho Department of Water Resources Director Gary Spackman recently determined groundwater pumpers owe surface water irrigators 45,000 acre-feet of water to offset diminished Upper Snake Plain storage carryover due to their pumping.

Absent any replacement water, IDWR would send curtailment notifications to groundwater pumpers with a priority date after July 1, 1985.

For the first time, pumpers are utilizing an option to spread their mitigation burden over several years, rather than replacing all of the water at once. Annual obligations-11,924 acre-feet in the first year, 9,022 acre-feet in the second year and 3,824 acre-feet in the third year-are based on the diminishing volume of water that would return to the Snake River each year through curtailment of junior pumpers.

Though IDWR modeled obligations covering the next two decades, it's unlikely replacement water will be owed for more than a few years, since the burden is erased once storage reservoirs completely refill, explained IDWR Deputy Director Mathew Weaver. But Weaver worries pumpers will face a deeper hole if there's another dry year, potentially resulting in curtailment orders if they couldn't meet the combined mitigation requirement.

"We might have to go out and curtail, and we've never had to do that on the Surface Water Coalition water call," Weaver said.

Lynn Tominaga, executive director of Idaho Groundwater Appropriators, said the challenge of leasing replacement water has left his members with no better options. Pumpers have already paid the City of Pocatello $25 per acre-foot for 10,000 acre-feet toward the director's mitigation order-compared with the $7 per acre-foot they paid in 2012. Tominaga said he's investigating a few options to lease the final 1,924 acre-feet of this year's burden.

"The issue is we've approached folks to try and buy some water, and what they've said is, `We're not selling because we don't know if we're going to have enough snow or not and what the weather conditions are going to be,'" Tominaga said.

The vast majority of the pumpers' water debt is owed to surface water irrigators with rights in American Falls Reservoir, which fills completely in 90 percent of the years. Since American Falls is the system's final reservoir, Tominaga emphasized replacement water will be flushed to free storage space, wasting his members' roughly $250,000 investment if the reservoir fills as he hopes.

Surface Water Coalition attorney Travis Thompson said his organization is likely to petition the IDWR director to reconsider his decision allowing pumpers to spread out their obligation. He's concerned about the uncertainty the policy would cause his members regarding their water supply.

"If you have an established injury and that's not mitigated in a timely fashion where it protects the seniors' rights, I think you've got a problem with what's being provided," Thompson said.