Trump's Energy Department sues to control Idaho's 'lifeblood' for nuclear lab

The federal government has filed a lawsuit against the state of Idaho, seeking to block the state from curtailing water use at Idaho National Laboratory and from administering federal water rights, court records indicate.

On Sept. 11, the U.S. government filed a lawsuit against the state, the Idaho Department of Water Resources and Idaho Department of Water Resources Director Mathew Weaver in U.S. District Court.

Arguing that the federal government has supremacy over the states, the lawsuit seeks to throw out a water curtailment order that would apply to Idaho National Laboratory and block the department and Weaver from administering any federal water rights in Idaho in the future.

There is also a legal question over whether the case should be heard in federal court or in state court.

For purposes of the case, water curtailment means shutting off the water completely.

“Through the order, and (Idaho Department of Water Resources’) program of administering water rights, defendants are attempting to directly regulate federal agencies,” the lawsuit states. “However, federal installations are shielded by the supremacy clause from direct state regulation, unless Congress has provided clear and unambiguous authorization for such regulation.”

In a response submitted Oct. 16, attorneys for the state of Idaho denied the allegations in the federal government’s lawsuit and countersued the federal government.

Idaho Attorney General Raúl Labrador said the U.S. Department of Energy and Idaho National Laboratory should have to follow the same water laws as any other water user in Idaho.

“Water is the lifeblood of Idaho, and my office will protect the water rights of Idahoans who depend on it,” Attorney General Raúl Labrador said in a written statement Tuesday. “Our sovereign authority to administer those rights has been established for more than 100 years, and it applies to every water user in this state, including the federal government. The federal government gets no special treatment under Idaho law. We will work with federal agencies to meet their needs, but we will not sacrifice the water rights of Idaho farmers, ranchers, and families to do it.”

In their response to the federal lawsuit, state attorneys wrote that the feds’ lawsuit, “threatens injury to other decreed water rights, and threatens to fundamentally undermine the state’s sovereign authority to allocate and administer Idaho’s waters according to Idaho water law.”

Idaho Gov. Brad Little’s office also put out a statement saying Little will protect Idaho water resources.

“Gov. Little has a strong track record of fighting for Idaho’s water sovereignty, and he will continue to put Idaho first,” the governor’s office said in a written statement Tuesday. “The state of Idaho continues to work responsibly with the Department of Energy toward a mitigation plan that meets everyone’s needs and protects Idaho’s water resources.”

The stakes in the case appear to be high.

“This disputed issue is ripe for resolution because resolution of the issue will affect the administration of every other decreed water right in the coalition delivery call proceedings – both state law-based water rights and federal reserved water rights,” state attorneys wrote.

With Idaho and much of the West experiencing drought and climate change, water is a precious resource in Idaho that farmers and water users have fought over for decades.

Meanwhile, Idaho National Laboratory is ramping up nuclear projects at its 890-square mile complex in eastern Idaho and discussing adding data centers.

Idaho is also one of the finalist states to host a new U.S. Department of Energy Nuclear Lifecycle Innovation Campus, though officials have not said where the campus might be built, the Idaho Capital Sun previously reported.

Why is the federal government suing Idaho’s state government?

According to court documents, the U.S. Department of Energy holds a water right in the amount of 35,000 acre-feet annually in Idaho.

An acre-foot is a unit of volume that expresses how much water it would take to cover one acre of land in water that is one foot deep. For comparison, one acre is a little bit smaller than a football field.

The issue came to a head in May when Weaver issued an order curtailing water rights established after Oct. 11, 1900.

Idaho’s water laws are governed by a seniority-based framework. Simply put, when there is not enough water to go around, the oldest, or senior, water rights have priority over the newer, or junior, water rights.

If the director of the Idaho Department of Water Resources determines that the junior water rights holders are injuring senior water rights holders by taking water that the senior water rights holders have a right to, then the director can issue a curtailment order cutting off the water for junior water rights holders.

Under the terms of a 2024 state water settlement agreement, water users can protect themselves from water curtailment by joining a ground water district and participating in an approved mitigation plan, the Idaho Capital Sun previously reported.
The U.S. Department of Energy did join the Big Lost River Ground Water District to participate in mitigation and protect itself from curtailment, but only joined for the 2026 water year, court records indicate.

However, through the lawsuit, the federal government is challenging Idaho’s ability to enforce those water rights.

“The (curtailment) order, and Idaho’s statutory scheme which authorized it, unconstitutionally and unlawfully seeks to require the United States’ participation in a state administrative proceeding for which the United States has not waived its sovereign immunity, and to directly regulate federal agencies contrary to the supremacy and property clauses of the United States Constitution and the principle of federal sovereign immunity,” the federal government’s lawsuit reads.

The federal government said there could be safety, economic and energy consequences if the state shuts off the U.S. Department of Energy’s water for Idaho National Laboratory.

“Curtailment of INL’s water right would disrupt this national nuclear energy momentum,” the lawsuit states.

“Forcing these facilities to curtail operations poses nuclear safety risks and would halt research support for the Navy’s nuclear-powered warships and commercial advanced reactor licensing,” the lawsuit continued.

Idaho Capital Sun is part of States Newsroom, a nonprofit news network supported by grants and a coalition of donors as a 501c(3) public charity. Idaho Capital Sun maintains editorial independence. Contact Editor Christina Lords for questions: info@idahocapitalsun.com.