This article originally appeared in the Yakima Herald-Republic.
In a rare move, all surface water rights holders in the Yakima River Basin will see their water curtailed due to lack of available water.
The Washington Department of Ecology is ordering a halt to surface water use from Oct. 6 through the end of October, according to a news release.
Record-low reservoir storage and poor stream flows as the basin suffered a third year of drought conditions led to the decision, which Ecology calls a necessary step to preserve water for fish and the most senior water rights. Available water is expected to run out on Oct. 6.
Ecology estimates the restrictions may affect more than 1,500 water rights holders.
Washington water law has a seniority system based on priority dates. When water supplies are low, the most senior rights holders still receive their full amount before junior water rights holders can access theirs. But water supplies have dipped so low that nearly all water rights holders will see their use curtailed.
Seniority for about 2,300 surface water rights was sorted out in the 40-year court case Ecology v. Acquavella, also known as the Yakima Basin adjudication. Final appeals were decided in 2021.
“This is the first time we’ve had to enforce that regulation based on those dates,” said Emily Tasaka, an Ecology spokesperson.
Pro-ratable districts such as the Kittitas Reclamation District and the Roza Irrigation District already shut off water, on Aug. 13 and Sept. 24 respectively, after seeing only 40% of their allotment for the water year.
Relatively senior districts, which typically have seen most of their allotment even during the recent drought years, also will be shutting down. The Sunnyside Valley Irrigation District will begin dewatering the Sunnyside canal on Oct. 5 in preparation for an Oct. 6 shutoff. Some laterals and deliveries may have water for a few days beyond that date as the canal is draining. The Yakima Tieton Irrigation District shut down Oct. 1.
The Yakama Nation holds the most senior water rights, dating back to the Treaty of 1855, which is delivered through the Wapato Irrigation Project.
But even that water will have to shut down early as well, said Phil Rigdon, superintendent of Yakama Nation’s Department of Natural Resources.
Total system storage of the Yakima Project’s five reservoirs was at 8%, among the lowest on record, on Oct. 1.
Without reservoir water, natural flows are not enough to fulfill irrigation demands, including for municipal use.
The order will put a test to the decades-long workgroup, made up of federal, state, local and tribal entities, that has created the water management framework called the Yakima Basin Integrated Plan.
“For years, the Yakima Basin has been a national model for collaboration and water management,” said Casey Sixkiller, Ecology’s director, in a press release. “That partnership has led to more than $1 billion in investments. But the conditions we see today show that there is much more work still ahead of us to improve water security for the region.”
The City of Yakima
While he hasn’t seen a curtailment like this in his career, Mike Shane, water and irrigation manager for the City of Yakima, said that the city is well-positioned to have enough drinking water to meet demand through its wells, but will shut off irrigation early.
“This is a significant and unprecedented time,” Shane said.
The city diverts water from the Naches River at the Nelson diversion to supply both drinking and irrigation water. It also has four groundwater wells that support drinking-water demand.
But it’s not unlimited, and scaling back water use is necessary. The city is asking residents to prepare for irrigation water to be shut down on Oct. 6, a week earlier than usual.
“Groundwater supply alone does not meet peak demands,” Shane said. Those demands are usually in the summer, however.
Shane said the process of switching system water from diverting water from the Naches River to wells is not uncommon, such as when the river freezes or there is high turbidity in the river water.
Some residents and businesses have irrigation water that is fed through the drinking-water system.
He has called on residents and city departments to cut back on unnecessary water use, particularly lawn and landscape irrigation.
“We should be fine,” Shane said.
Kittitas County’s response
Arden Thomas, water resources manager for Kittitas County, said the county is working with communities reliant on the river and assessing this order’s impact on them.
“Everybody should recognize how critical this drought is and do their part,” Thomas said. “This is unprecedented.”
Work has been done in the Upper Yakima Basin to secure senior water rights for domestic water use to help the supply, Thomas said. She is hoping that the orders are short and natural river flows return soon.
The restrictions will affect some communities in Kittitas County more than others. Ellensburg and Kittitas rely on groundwater, so aren’t directly impacted.
Roslyn and Ronald use surface water from Domerie Creek for domestic needs, and will be affected.
“While we hold senior water rights, this is the first time curtailment has extended to pre-1905 rights basin-wide,” Roslyn Mayor Jeff Adams said in a statement. “We urge residents to understand the gravity of the situation and reduce usage immediately.”
In a shared system, Cle Elum, South Cle Elum and Suncadia use surface water from the Yakima River but have emergency wells for limited backup use.
Cle Elum Mayor Matthew Lundh said that he is working with Kittitas County and other communities on how to address the situation. Cle Elum says their emergency wells alone are not enough to meet demand.
“We’re currently evaluating what our options are,” Lundh said.
Ecology to notify water rights holders
Ecology will notify water rights holders of the restrictions by mail, and Ecology staff will check to make sure diversions are off.
Ecology will work with the U.S. Bureau of Reclamation to monitor flows and notify water rights holders of any changes.
People with questions can call Ecology’s service line at 509-575-2597 or email wrcro@ecy.wa.gov.
Questen Inghram is a WSU Murrow News Fellow based at the Yakima Herald-Republic, which originally published this article on Oct. 2, 2025.