Idaho water officials warn rights holders of potential curtailment

Users of water from the Eastern Snake River Plain Aquifer could have their water rights curtailed next spring. The aquifer stretches from an area north of Rexburg in eastern Idaho to a point west of Gooding in south central Idaho.

The Idaho Department of Water Resources on Oct. 24 mailed letters to ground water users hydraulically connected to the aquifer. The letters warned junior water rights holders of potential water curtailments.

Water Resources officials said in a release that they sent the letters as part of a continuing response to water delivery calls that senior water rights holders made in 2005.  Seven water delivery organizations that comprise the Surface Water Coalition, and senior spring water users Blue Lakes Trout Co. and Clear Springs Foods’ Snake River Farm facility, issued the 2005 calls.

Idaho law allows a senior right holder who experiences a shortfall in its authorized amount of water to make delivery calls to junior rights holders – if the senior can put the water to beneficial use, Water Resources officials said. The state’s “conjunctive” water management rules incorporate the impacts of ground water pumping on surface water supplies. Junior rights holders must mitigate or replace the impacts of their depletions to the aquifer, or stop diverting water.

Idaho water officials sent warning letters to about 1,700 water rights holders. Curtailments, if required, could impact about 3,000 water rights in 2009. Rights potentially affected include those for irrigation; commercial, industrial municipal and non-exempt domestic uses; and other consumptive uses. Non-consumptive uses and culinary in-house uses would not be subject to water-delivery calls.

The curtailments could impact certain ground water users with junior water rights in portions of Gooding, Lincoln, Jerome, Cassia, Minidoka, Blaine, Bingham, Power, Jefferson, Bonneville, Butte and Bannock counties in south central and eastern Idaho.

Rights junior to May 12, 1977, in the Surface Water Coalition delivery call area and Jan. 4, 1973, in the Thousand Springs delivery call area could be impacted in a worst-case scenario, Idaho Department of Water Resources officials said. That scenario is based on conditions in 1977, when spring runoff was 45 percent of normal.

Idaho experienced a good water year in 2008, and there will be much more carryover storage water than in 2007, Water Resources Director David Tuthill said. As director, he is obligated to give early notice to water users who could be impacted by water calls so that those users can make plans if shortfalls occur, he said.

Water Resources officials a year ago sent a warning letter to about 2,700 recipients. This year’s letter went to fewer rights holders because Idaho has more water carried over, in storage, Tuthill said in an interview.

Sending out warning letters could continue in subsequent years, regardless of water supplies, he said. “It would be my expectation to do this until we have a long-term mitigation plan in place,” he said.

A mitigation plan for the Blue Lakes water call is in place but is not yet permanent, Tuthill said.

He said that ultimately, he expects the ground water users to establish a long-term mitigation plan. Users would file a plan subject to Idaho Department of Water Resources review and action. The dairy industry and some food processors have submitted some smaller-scale mitigation plans for review.