BOISE — The Idaho Supreme Court could decide this year how Boise River system reservoir water released to prevent flooding should be accounted for.
Treasure Valley irrigators say water released for flood control purposes should not be counted against their reservoir storage rights.
The Idaho State Department of Water Resources says it should and the two sides have fought over the issue for several years.
Judge Eric Wildman, presiding judge of the Snake River Basin Adjudication Court, ruled in favor of the state last summer.
Irrigators have appealed that decision to the state Supreme Court, and both sides say a decision could be issued before the end of the year.
In a second, related decision that went in favor of the irrigators, Wildman ruled that a water right exists for water that is stored in the reservoirs following flood control releases.
He sent that issue back to a special court master to decide the priority date of those water rights. That ruling is stayed until the Supreme Court decides the major issue of how flood control releases should be accounted for.
The Treasure Valley Water Users Association, which is representing irrigators on the issue, is using this year’s unusually high river flows to point out the danger the state’s stance poses to irrigators.
TVWUA Executive Director Roger Batt pointed out that more than 1 million acre-feet of water has already been released to prevent flooding in the valley.
The system’s three reservoirs have a combined storage capacity of 983,000 acre-feet.
The water releases began when fields and canals were mostly still under snow and ice and too wet to work the land, Batt said.
Irrigators in the region rely on natural flow in the Boise River until June in an average year and then turn to water stored in the reservoir to finish the season.
Under the state’s stance, irrigators’ reservoir storage rights would already be exhausted, Batt told Capital Press.
“Applying the state’s theory, we would have zero storage water for the irrigation season (this year),” he said. “If that came to fruition, we would literally have exhausted all of our storage water rights because of flood control releases this year.”
IDWR Deputy Director Mathew Weaver said the department feels vindicated by Wildman’s ruling. The many public comments the department used to receive on the issue have mostly evaporated since the decision, he said.
In his ruling, Wildman wrote that the arguments put forth by water users “would effectively transfer water right distribution in the basin from the (IDWR) director to the federal government....”
Aside from being contrary to the prior appropriation doctrine, Wildman wrote, “this would cripple the director’s ability to effectively distribute water under our system of water rights administration.”
Weaver said the department is still hopeful the sides can reach a settlement, but Batt said any settlement offer that includes subordinating senior water rights to junior rights is a non-starter.