State official issues water curtailment order for many eastern Idaho users

IDAHO FALLS (Idaho Capital Sun) — Idaho Department of Water Resources Director Mathew Weaver issued a curtailment order Thursday afternoon that requires 6,400 junior groundwater rights holders who pump off the Eastern Snake Plain Aquifer to shut off their water.

The order would affect groundwater users that the Idaho Department of Water Resources said are not in compliance with state mitigation plans, according to a news release the department issued Thursday. 

“It is surprising to us that six groundwater districts would choose not to live by the terms of either of their approved mitigation plans and subject their members to curtailment,” said Brian Patton, deputy director of Idaho Department of Water Resources, in a written statement.

Idaho Gov. Brad Little issued a statement supporting the order on Thursday afternoon.

“Water curtailment is never desired, but the director must follow Idaho law and the Constitution in issuing this order,” Little wrote.

The order would affect about 500,000 acres of agricultural land in eastern Idaho and the Magic Valley if the groundwater water users do not come into compliance. Groundwater users who have not participated in a groundwater district for mitigation purposes will have 15 days to join a plan or face curtailment, the Idaho Department of Water Resources said. 

In a statement released Thursday night, the Idaho Groundwater Appropriators criticized the order, which it described as the single largest curtailment of water use in state history. The Idaho Groundwater Appropriators said the order would dry up hundreds of thousands of acres of farmland and could cause a hit to the state’s economy totaling hundreds of millions of dollars in economic losses.

“What remains is an utterly absurd situation, where hundreds of thousands of acres of farmland, and their associated economic benefits, are thrown away during a wet year to cause a small amount of additional water to overflow from the aquifer into the Snake River,” Idaho Groundwater Appropriators attorney TJ Budge said in a written statement Thursday night.

Under Idaho law, Weaver will issue an updated order in July that takes into account the new water supply and crop needs, the department said. 

Water rights in Idaho are governed by what is referred to as the doctrine of prior appropriation, which means “first in time, first in right.” When there isn’t enough water to go around the senior water rights holders get their water first and junior water rights holders get shut off – or curtailed – if there is not enough water to go around. 

“Idaho must maintain our water sovereignty and not turn out like other western states in the Colorado River Basin, such as California, where the federal government stepped in to supersede the state’s control of its water,” Little said in his written statement. “We absolutely must conserve water for future generations, which is why the Legislature and I championed half a billion dollars in historic investments in recent years to modernize water infrastructure statewide.”

“My administration has been engaged on this issue for years, most recently through the formation of a Groundwater Management Plan Advisory Council,” Little added. “The users should determine their own destiny, and the creation of the council will continue to help them to find solutions outside government. Idahoans have always and will continue to solve our own problems, and we remain committed to working with all water users in Idaho to ensure we have a sustainable supply of water for this generation and future generations.”

“If we continue the status quo with water use on the Eastern Snake Plain, we are setting our children and grandchildren up for failure,” Little said. 

How do water rights work in Idaho?

Generally in Idaho, surface water users have senior rights, while groundwater users have junior rights. 

For example, the Twin Falls Canal Co. holds senior water rights dating back to 1900. The curtailment order that Weaver issued Thursday affects groundwater users who hold junior water rights to 1954.

On April 18, Weaver issued a water methodology order for the 2024 irrigation season that determined a shortfall of 74,100 acre-feet of water to the Twin Falls Canal Co. Weaver gave junior water rights holders until May 2 to supply notices to the Idaho Department of Water Resources that they are in compliance with their approved mitigation plans, the Idaho Department of Water Resources previously announced in a May 10 press release. 

Thursday’s new curtailment order would apply to groundwater users that the Idaho Department of Water Resources has determined are not operating under an approved mitigation plan. Those groups include the Bingham Groundwater District, Carey Valley Groundwater District, North Snake Groundwater District, Magic Valley Groundwater District, Bonneville-Jefferson Groundwater District and the Jefferson-Clark Groundwater District. 

Several other groundwater users are operating under an approved plan and will not be curtailed, including the Coalition of Cities, Southwest Irrigation District, Henry’s Fork Groundwater District, Madison Groundwater District and others. 

The prospect of curtailment for junior water rights holders is not a new issue. Water issues have been litigated in Idaho courtrooms for decades, with a key settlement agreement reached in 2016. More recently, the Idaho Department of Water Resources issued an order last year that contained a curtailment order that was put on hold pending a hearing with the department, the Idaho Capital Sun previously reported. Ultimately, the department didn’t shut off the water last year after finding there was no water shortfall at that point last summer.