This story is part of The Salt Lake Tribune’s ongoing commitment to identify solutions to Utah’s biggest challenges through the work of the Innovation Lab.
There are some clear consequences to Great Salt Lake drying up.
Habitat losses for migratory birds. Dents in the $1.3 billion generated each year by mineral extraction, the brine shrimp industry and tourism. An impact on human health as dust from the dry lakebed — some areas of which contain elevated levels of arsenic — contributes to air pollution.
But a consequence you may not have thought about before is dusty snow.
As the lakebed dries, dust can land on the state’s snowpack in the mountains, causing the snow to absorb more sunlight and melt faster.
This, in turn, means more water becomes absorbed in the soil and doesn’t reach the lake.
And while Great Salt Lake’s decline has been caused mainly by diversions of water upstream for residential and agricultural use, loss of snowpack melt certainly doesn’t help it, or the rest of the state.
McKenzie Skiles, a geography professor at the U. who studies the impact of dust on snow, said the simplest solution to controlling Utah’s growing dust problem is keeping more water in the lake.
She’s also a member of the DUST^2 (Dust across a Desert-Urban-Summit Transect) project, a group of six scientists studying the impact of dust on study sites from southwestern U.S. deserts to Utah’s Rocky Mountains.
She pointed to Owens Lake in California, which became desiccated in the 1920s after its tributaries were tapped and diverted to Los Angeles, resulting in an air pollution disaster that has cost California residents more than $2 billion to mitigate.
Blowing particulates from the dry lakebed caused health issues for the 40,000 people living nearby. By comparison, Owens Lake is about one-sixth the size of Great Salt Lake, and Salt Lake County alone has a population of more than 1 million.
And if all of that isn’t enough motivation to do something about the dust, consider this: Skiles said although Utah gets the most dust in the spring, skiing and snowboarding aren’t as good on dusty winter days.
“If we try to do dust mitigation… after we are already getting high dust emissions, it’s going to be very costly,” Skiles said.
Ways to control the dust
Maura Hahnenberger, another DUST^2 scientist who teaches geosciences at Salt Lake Community College, studies where dust comes from and how it gets transported.
She suggested some possible techniques for controlling the Great Salt Lake’s dust problem.
One option is revegetating a dusty area; however, that probably wouldn’t work well for the Great Salt Lake, since not much vegetation can thrive around it to start with.
Another idea is simply not disturbing the dried up lake bed soil. Hahnenberger said dust blows away when it’s loose, but some dried up areas form a thick crust that keeps the dirt packed down, and those should stay intact.
A third option would be replenishing the lake water. Hahnenberger said even keeping the lake level stable and not allowing it to slip any lower would help.
Hahnenberger said there aren’t good numbers yet when it comes to questions about how much dust levels are increasing as the Great Salt Lake dries up — that’s the kind of topic that the DUST^2 project is currently exploring — but she noted that when she began studying dust in the 2010s, the Great Salt Lake shoreline was not identified as a large producer of dust events.
But over the last five years, Hahnenberger said scientists began regularly seeing dust from the Great Salt Lake.
It’s causing an increase in particulate matter levels, she said, visible on days like February 5, 2021, when there was so much dust that brown snow fell.
On that day, Hahnenberger said the maximum value of particulate matter levels was 286 micrograms per meters cubed. The threshold at which people begin experiencing health impacts, she said, is 35 micrograms per meters cubed.
“Once you create a dust source, particularly on these dry lake beds, it’s hard to keep the dust down,” she said.
Impacts on early snowmelt
Skiles said dusty snow research is still ongoing in Utah, but when she studied this process in the upper Colorado River Basin, modeling studies showed that the area lost up to 5% of the water yield due to earlier snowmelt. White snow reflects sun well, but dusty snow absorbs more energy, increasing the pace of snowmelt.
That doesn’t mean that the runoff would necessarily be more polluted. Skiles said snowmelt pollution levels depend on what’s in the dust; in the Great Salt Lake’s case, there are heavy metals present, but “luckily, we have really good infrastructure where we treat water to make sure it’s safe for our consumption.”
Skiles said dust on snow can shift snowmelt timing on a scale of weeks to months, which impacts how efficiently the resource gets used.
It can also throw off mountain ecosystems, she said, by changing how early vegetation begins growing again.
“Ultimately, plants end up taking up more water in this sort of earlier shift, and we get less water downstream,” she said.
Skiles added that the Great Salt Lake has often been undervalued because it’s salty and smelly, but people should acknowledge all the good it does as a useful resource.
“We need to switch our view of the value of the Great Salt Lake and just allow more water to run into the lake,” she said.
