Idaho’s water supply is commonly coded with industry acronyms: CFS, SWE, KAF.
This winter, the grim facts were clearly written on the landscape – on gray hills, dry peaks and early spring flowers.
Now, as Idaho’s irrigation season begins in earnest, experts are sounding the alarm about a severe water outlook with few precedents in the state’s history, whether they’re talking in terms of cubic feet per second, snow-water equivalent, or thousands of acre-feet.
Idaho Department of Water Resources hydrologist David Hoekema went on to find a comparable case in 1934 – the heart of the Dust Bowl.
At an April meeting of Idaho’s Interagency Water Supply Committee in Boise, experts warned that harsher forecasts threaten to reach beyond Idaho’s water-dependent $44.5 billion agricultural economy, affecting how people across the state work, play and pay their electricity bills.
“This year, water is so low that every Idahoan will feel the impact,” Erin Horton, a water supply specialist with the federal Natural Resources Conservation Service’s Idaho state office, told the Idaho Statesman in an interview.
Horton spends the winter monitoring snowpack in river basins around the state. She described the “mindboggling” scenes in the mountains – bare waste in March that she expects to melt in May. On April 8, Idaho’s snow-water equivalent — that is, the amount of water in its snowpack — was the lowest it had seen on that date, effectively resetting the state’s scale.
A light blanket of snow arrives in the Foothills in January, one of the few snowfalls to reach Idaho’s capital this year. The Boise River Basin received about a third of its normal snowfall this winter, according to some models.
(Sarah A. Miller/smiller@idahostatesman.com)
Idaho was one of 10 states to see the warmest March this year, according to the National Oceanic and Atmospheric Administration, which Hokema called “far and away” the warmest winter the state has seen since extensive record-keeping began.
“It’s something you don’t expect to see for another 100 years, if that,” he told the Statesman.
This means that small snow melts quickly and quickly. The snowpack was so low, and the weather so warm, that SNOTEL — short for snow telemetry, the West’s automated network of real-time snow monitoring consoles — couldn’t sense it, according to a cadre of hydrologists, meteorologists and other concerned scientists gathered in the city on Wednesday.
SNOTEL sites are “highly biased,” according to Mark Robertson, co-owner of M3 Works, a software company that works with Water Resources to model snowpack in the Boise Basin.
SNOTEL stations measure snow-water equivalent and precipitation. Snow lands on a “pillow,” where the station measures its depth, density, and moisture content of the surrounding soil. From there, it’s a math problem, extrapolating data from available sites to estimate the amount of water in the basin. The equation assumes a historical average snowline of 4,000 feet in most basins, Hokema said. This year, the summer weather has greatly increased the snow.
According to Robertson, the Boise Basin receives 60% of its annual moisture from Snowtail. A different model Robertson ran to account for extreme heat put this figure much lower: around a third of ordinary water. A third, hand-sample estimate agreed with Robertson’s, was 42% of what is commonly obtained in the basin.
At that level, there’s “virtually no chance” of getting a “so-called normal snowpack,” Brad Gillies of NOAA’s Oregon-based Northwest River Forecast Center told the committee.
“We haven’t really had a winter,” Water Resources Deputy Director Brian Patton told the Statesman on April 2, “and we’re very concerned about the water supply.”
‘It’ll Be Bad’ Without the Miracle Spring
Idaho’s 2026 statewide snow-water equivalent — the amount of moisture in the state’s snowpack, seen here in black line — was the lowest on record on April 8.
Idaho’s low snowpack broke a “ton of records” for shortages across the state, Horton said. Those figures led the National Resource Conservation Service to forecast “below normal” natural flows across all of Idaho, with a median projection for the Boise River where it usually hits.
Most of the water that Treasure Valley residents see in the river isn’t natural flow—it’s regulated by upstream dams and reservoirs. And that’s why Boise area water users are in better shape than their peers who rely on Snake, Owehi or other regional sewers, Hokema said.
Reservoirs at Anderson Ranch, Arock and Lucky Peak in the Boise Basin have enough water stored to handle a bad year, he said. Both he and Horton used the same simile: “Water in a reservoir is like money in a bank,” Horton said.
This year, Hokema said, the Boise Basin will likely bring the account to zero by the end of the year, starting as soon as the water is released.
“I would like to see the reservoir system completely finished,” he told the Statesman. “We’ll get through this year, but next year, we’re going to be in really, really bad shape.”
Boise’s reservoir system is designed to handle a one-year drought, he said. If it goes on too long, without water in reserve, Hoekema expects to “see some really, really bad consequences.”
Still, spring can change quickly in Idaho’s mountains. While forecasters agree it will be difficult to make much ground, the weather will traditionally “play a really important role” in water supply in the coming weeks, Hokema said.
Boise’s reservoirs — Anderson Ranch, Arrowrock and Lucky Peak — were at 89% of capacity on April 8. Experts warned that the reservoirs could run out by the end of the year.
“We’ll see what happens,” he said. “If we dry up, wow – it’s going to be bad.”
Unfortunately, this is the most likely weather pattern, according to Troy Lindquist, a senior hydrologist at the National Weather Service.
Idaho has a “very strong chance” of above-normal temperatures and below-normal precipitation in the coming months, he told the committee. Furthermore, Lindquist sees a good chance for an El Niño weather pattern to form in the Pacific. Here, that possibility—but not always—carries warm, dry weather.
What’s next for Idaho, out
Despite the bleak outlook, Boise is in better shape than the rest of the state — and Idaho is in better shape than other states in the region.
To the east, users who rely on the Snake River are in much worse shape, Hokema said. Farms south of Twin Falls, which receive most of their water from the South Hills of northern Nevada and Idaho, could run out of water by the end of May, he said.
A week before the meeting, Horton spoke with water users near Oakley who are planning to cut grass before leaving the fields. Other farmers, Hokema said, are already considering moving on from water-intensive cash crops like potatoes, sugar beets and soybeans in favor of alfalfa or wheat.
In an interview, Horton emphasized that the effects of bad water years extend beyond Idaho’s agricultural economy. Daily entertainment will take a hit, she said, as well as the businesses that depend on it. Low water will affect outfitters, fisheries, boaters and even hunters, she said.
Electricity prices may rise. Prices in Idaho follow the water supply, according to an Idaho Power representative at the water supply meeting. Hydropower is the company’s lowest-cost source, he said: Lower streamflow means dams produce less electricity, so Idaho Power fills the gaps with cost-effective alternatives.
“The plan is really important to us,” said an Idaho Power representative, “we’re not as bad as Colorado or California.”
Kristina Lazar, spokeswoman for the Idaho Office of Emergency Management, said it’s always a “scary day” when she hears about a low-water year. His office has things you can’t plan for, like wildfires. Lazar told the committee that her organization — as well as friends across the West — is “preparing” for an intense fire season due to dry conditions left behind by low winter tides.
“Everybody is having the same problem at the same time,” she said.
Boise just broke a century-old temperature record. How hot it has been here
Warm weather, light snow: How an unusual winter has affected Idaho ski areas
Bogus Basin will close weeks earlier than usual. Blame the unusual weather
