The water levels of the Great Salt Lake have dipped to troublingly low levels this August – lower than any in recorded history. But what does this mean for the people and wildlife that call Utah home? (Part 1 of 2)
The following is an unedited transcript.
Jim Steenburgh, a professor at the University of Utah, studies Utah’s precipitation and weather.
"For the Great Salt Lake diversions, what we use for agriculture and residential use is a big contributor to the low lake levels. Like right now, it's not just because we've had a decade of dry weather, but you know, every year we're siphoning off some of the runoff for the lake.”
Steenburgh said an often overlooked side effect of low lake levels is a suffering snowpack.
The Great Salt Lake generates significant snowfall through what’s known as the “lake effect”, which causes more precipitation to fall in areas near large bodies of water. As the Great Salt Lake continues to dry, less water means less snow, which means fewer powder days for skiers and snowboarders along the Wasatch.
But less snow doesn’t just affect winter recreation- 95% of Utah’s water supply comes from snowmelt. After a summer where the state has endured a severe megadrought, the snowpack of the 2021-2022 winter season will play a crucial role in refilling depleted reservoirs across the state.
To make matters worse, winter precipitation is likely to come increasingly as rain as temperatures warm globally.
Steenburgh explained that snow is expected to melt faster as the lake dries, meaning snowmelt will contribute less water to streams and rivers as the summer months roll by.
“The snowpack in northern Utah is the first and most important reservoir for water resources in our state. It gets built up, you know, during the winter, and then it melts quickly in the spring, giving us this big pulse of spring runoff that we all benefit from, because we use that water for irrigation and for, you know, personal use. But it's also important for maintaining the level of the Great Salt Lake. So that runoff is basically what recharges the lake every spring.”
While warmer spring temperatures are likely to melt snow earlier, another culprit may increase snowpack melt: dust.
“The thing about dust is, you know, snow it naturally it reflects a lot of sunlight back to space, but when you had dust in the snow, it's darker, it absorbs more sunlight. So what happens is the snow melts faster. And so it affects the timing of the melt.” Said Steenburgh.
Not only is dust a concern for the snowpack, but it’s also a concern for human health.
The Great Salt Lake is a terminal lake, which means no water flows out of it. As a result, what flows into the lake stays in the lake. When water evaporates out of the lake, it leaves behind salt, chemicals and heavy metals, which settle in the sediment that lines the lakebed. Unfortunately, Steenburgh said, as the lake dries, more lakebed, and therefore more toxic sediments, are exposed.
“The lake level goes down, it exposes more of the surfaces that were previously covered by water. If those surfaces are left undisturbed, they're not necessarily huge dust emitters. But if they are disturbed, you know, if people are out there trampling on them or things like that, then they become dust emission sources.”
When carried by winds from the west, the sediment may be deposited anywhere along the Wasatch front.
Looking to the future, Steenburgh emphasized the importance of addressing climate change which is behind the warmer temperatures the West is experiencing.
“When we look out a few decades, like what's gonna happen over the next couple of decades depends on prior greenhouse gas emissions. But farther out, yeah, that would depend on the decisions we make today about how we're going to produce energy and that sort of thing.”