The future is not bright for Idaho's water supply, forecasters say
When David Hoekema, a hydrologist for the Idaho Department of Water Resources, presented Idaho’s water outlook to the Water Resource Board last week, he said he didn’t have good news to share.
“The future is not bright,” he said.
Though the state started off the water year on a positive note, with above-normal precipitation in most regions in October and December, most measurement devices scattered around the state saw record low accumulations of snow and rain in 2022.
Every basin in the state is expecting a water shortage this summer, which means most areas will have farmers who won’t get all the water they need to grow their usual amount of crops.
The forecast is particularly grim at the headwaters of the Snake River.
Last fall, Hoekema cautioned that early-season storms alone wouldn’t be enough to pull the state out of the drought, which parts of southern Idaho have been experiencing for more than two years.
In fact, a high-pressure ridge over the eastern Pacific Ocean prevented storm systems from coming inland in January and February.
“After January 7th, the snow is pretty much turned off,” Hoekema said. “Very similar to last year when the precipitation just turned off in March, but this year it came earlier.”
Now, more than half of the state is in a severe drought, and that’s just expected to expand. There likely aren’t any big storm systems on the horizon to serve as a lifeline, according to precipitation forecasts and climate models.
Idaho’s mountain snow has already started melting. That means the runoff into the rivers will likely happen early – a pattern that research shows will continue with rising temperatures due to climate change – and speed up the timeline that irrigators need to tap into storage water.
If there’s one bright note, Hoekema told the board, it’s that summer temperatures could be closer to average, compared to last year’s heatwave.
“We’re hoping not to see those extremely hot temperatures we saw last year, and that would help stretch our water supply a little further,” he said.
Still, southern Idaho could have one of the worst drought years on record, with dry conditions set to intensity around Henry’s Fork and the Snake River, as well as the Owhyee and Bruneau rivers.
Find reporter Rachel Cohen on Twitter @racheld_cohen
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