During a recent storm in March, several shallow, plant-lined channels in the Lucky Estates subdivision in Riverton mimicked Mother Nature — and in doing so helped clean rainwater before it made it to Great Salt Lake.
Urban swales like this one are designed to slow, filter, and trap the kinds of pollutants that typically wash off streets and sidewalks during a storm: petrochemicals, oil, heavy metals, plastics, and organic materials. Without intervention, these materials flow untreated into storm drains, which lead to the Jordan River, a major tributary of Great Salt Lake.
At just 7 percent to 10 percent of the Great Salt Lake’s total inflows, stormwater may seem like a drop in the bucket, according to Rob Sowby, an environmental engineer at Brigham Young University. But Sowby and other experts stress that it’s not just about the quantity — it’s also about quality. Dirty water harms ecosystems, and clean water sustains them. As stormwater flows over roads and parking lots it picks up pollutants like nitrogen and phosphorus before reaching rivers that feed into Great Salt Lake.
"If you're just concerned about quantity and getting water to Great Salt Lake … then what you would do is you would pave the whole valley and make it all impervious and let all the water that falls from the sky run off to the lake,” Sowby said. “That would certainly get water to the lake, but the consequence is it would all be contaminated water, and that doesn't help our local streams, nor Great Salt Lake itself.”
(Samantha Hawkins) The University of Utah’s Landscape Lab, located at the Williams Building in Research Park and seen here May 5, 2025, was specifically designed for on‑site stormwater management, where runoff is captured, filtered by plant roots and soil, and used to recharge groundwater.
Stormwater runoff is thought to be a major source of pollution in the Great Salt Lake Basin, but measuring the contribution of stormwater pollution to the overall pollutant load is extremely difficult, according to Jeanne Riley, manager of the Utah Division of Water Quality’s general permitting section.
More than half of the watersheds that feed into the streams and rivers that feed into the lake —128 out of 247— are considered impaired, meaning they contain pollutants at levels that could harm aquatic life or human health, according to the Utah Division of Water Quality. Some of the most common contaminants include E. coli, heavy metals like copper, and low oxygen levels that make it harder for fish and other wildlife to survive.
The consequences of dirty water ripple throughout the lake’s ecosystem. Excess nutrients from stormwater runoff can trigger algal blooms, depleting oxygen in the water and endangering brine shrimp and microbial communities that sustain millions of migratory birds, according to Nicholas Von Stackelberg of the Utah Department of Environmental Quality. Pollution can also raise the lake’s salinity to levels incompatible with its food web, he said.
“We have a lot more impairments than resources to address them,” Von Stackelberg, an environmental scientist, said.
Solution found in low impact development
(Samantha Hawkins) Permeable concrete pavers at the Natural History Museum of Utah, seen here on May 5, 2025, allow stormwater to infiltrate on‑site, naturally filtering pollutants and recharging groundwater — part of the museum’s sustainable design.
One approach to addressing these challenges is Low Impact Development (LID) — a method of managing urban runoff that’s designed to mimic natural processes.
Some solutions blend into the landscape, like the vegetated swales— shallow, sloped, plant-lined channels often found along roads, parking lots, and parks — that absorb and filter runoff before it enters storm drains. Others work beneath the surface, such as underground stormwater storage systems that temporarily hold stormwater, preventing flooding and reducing pollution.
Green roofs capture rainwater before it even hits the ground, while permeable pavement allows water to soak through sidewalks and parking lots instead of carrying heavy metals and oil into waterways. Bioretention systems filter contaminants before runoff leaves a site.
Examples of LID already dot the Great Salt Lake Basin: the Natural History Museum of Utah uses permeable pavers to reduce runoff and recharge groundwater, while North Salt Lake City Hall’s bioretention rain garden filters pollutants from stormwater, and the University of Utah’s Landscape Lab slows and treats runoff with bioswales before it reaches Red Butte Creek.
Tom Beesley, flood control engineer at Riverton City, is pushing for more swales in new developments.
“Before we had white settlers in the valley, pollution that fell from the trees or came from animals ended up in the sagebrush and the grasses,” Beesley said. “And it was trapped in the sagebrush and the grasses and didn’t end up in the Jordan River in huge volumes. So it wasn’t a problem because mother nature managed that pollution with vegetation.”
Now, with modern infrastructure, runoff moves quickly and efficiently into nearby streams, bypassing natural filtration and contributing to pollution loads reaching the Great Salt Lake.
Like Lucky Estates, Riverton Business Industrial Park has also created swales to filter out contaminants by catching garbage, leaves, and debris before they reach waterways. Property owners are responsible to clean out their swales, instead of letting debris become “out of sight, out of mind” when it rushes down into storm drains, Beesley said.
“We basically bypass Mother Nature by doing that, but by putting pollution back into swales we actually mimic mother nature as much as we possibly can,” Beesley said. “Which I think is the only way we’re going to keep water resources, aboveground and belowground, clean.”
environmental design slows water to Great Salt lake
(Samantha Hawkins) The bioretention gardens outside of the North Salt Lake City Hall, as seen May 5, 2025, are shallow, vegetated basins that capture and filter stormwater runoff from rooftops and pavement. Designed with compost-amended soils and native plants, they slow the flow of water, remove pollutants, and support healthier groundwater.
But LID also introduces a challenge: while improving water quality, it delays the water’s journey to Great Salt Lake. Stormwater that infiltrates into the ground will likely reach the lake in about 50 years.
According to a 2023 study by the Utah Department of Natural Resources, an additional 31,200 acre feet of water would make it to the lake through 2060 if LID wasn’t used in future developments — representing 1 percent of the annual inflow to the lake. But it also showed that development with LID still gets more water to Great Salt Lake than undeveloped conditions.
Great Salt Lake needs around 770,000 acre-feet of additional water annually to reach healthy levels, according to the 2025 Great Salt Lake Strike Team report.
Getting rid of LID development requirements could “quickly get water to the lake,” said Rep. Thomas Peterson, R-Brigham City, during a meeting of the Utah Legislative Water Development Commission in June. “It not only presents an opportunity for us to avoid some evapotranspiration that would take place the longer [water] sits there, [as well as] ground saturation. But it also provides an opportunity for our cities and communities to have more buildable areas which provides more taxable property.”
He sought a bill during the last Legislative session earlier this year that would create a stormwater infrastructure fund to allow cities in the Great Salt Lake Basin to replace LID with other forms of infrastructure while maintaining water quality. The bill failed. LID in the basin has been required since 2020.
But experts warn we can’t just rely on traditional stormwater systems anymore. Decades of pipes and gutters have disrupted the natural water cycle, depleting aquifers that historically sustained the lake during dry periods.
“We have to regenerate groundwater,” said Sarah Erwin, a water quality specialist at Utah State University. “It’s just the nature of the system.”
In a natural system, precipitation and runoff seep into the ground, recharging shallow aquifers that eventually discharge clean water into the lake. But overuse and urban growth have disrupted this cycle — lowering water tables and reducing groundwater inflows that help sustain the lake during dry periods.
Not all groundwater will reach Great Salt Lake, according to Ryan Dupont, a professor of environmental engineering at USU. LID practices in the upper bench of the valley take water to a deep aquifer that isn’t directly connected to the lake. But stormwater that’s recharged to the shallow aquifers lower in the valley will eventually reach it, Dupont said.
Dupont pointed out that time delays in watersheds are actually beneficial by ensuring a more steady flow of water throughout the year.
Getting clean water to the lake will take a balancing act.
“We want to have enough water to get to the lake, but also not impair the health of our local streams and the ecosystems that they are a part of,” Sowby, the BYU engineer, said. “So that's what this is all about, is finding that balance, that nexus of water quality and water quantity for Great Salt Lake, as well as all of the upstream ecosystems and cities that use water.”
Great Salt Lake Collaborative director Heather May contributed to this story.
Note to readers: Samantha Hawkins wrote this story for the Utah Investigative Project while she was working at the Great Salt Lake Project. She now works for Grow the Flow, an advocacy organization for the Great Salt Lake.
