Note to readers \u2022 The following story was reported by The Utah Investigative Journalism Project in collaboration with The Great Salt Lake Collaborative.<\/p>\n
During a recent storm in March, several shallow, plant-lined channels in the Lucky Estates subdivision in Riverton mimicked Mother Nature \u2014 and in doing so helped clean rainwater before it made it to Great Salt Lake. <\/p>\n
Called urban swales, they 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. <\/p>\n
Stormwater contributes about 7 percent of Great Salt Lake\u2019s inflows, according to a 2023 state study<\/a>. That may seem like a drop in the bucket, says Rob Sowby, an environmental engineer at Brigham Young University.<\/p>\n But Sowby and other experts stress that it\u2019s not just about the quantity \u2014 it\u2019s 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. <\/p>\n \u201cIf you\u2019re just concerned about quantity and getting water to Great Salt Lake \u2026 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,\u201d Sowby said. \u201cThat would certainly get water to the lake, but the consequence is it would all be contaminated water, and that doesn\u2019t help our local streams, nor Great Salt Lake itself.\u201d<\/p>\n A major source of pollution<\/b><\/p>\n (Samantha Hawkins)\u00a0The University of Utah\u2019s Landscape Lab, located at the Williams Building in Research Park and seen here May 5, 2025, was specifically designed for on\u2011site stormwater management, where runoff is captured, filtered by plant roots and soil, and used to recharge groundwater.<\/p>\n 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\u2019s general permitting section.<\/p>\n More than half of the watersheds that feed into the streams and rivers that feed into the lake \u2014128 out of 247\u2014 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. <\/p>\n The consequences of dirty water ripple throughout the lake\u2019s 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\u2019s salinity to levels incompatible with its food web, he said. <\/p>\n \u201cWe have a lot more impairments than resources to address them,\u201d Von Stackelberg, an environmental scientist, said. <\/p>\n Solution found in low impact development<\/b><\/p>\n (Samantha Hawkins)\u00a0Permeable concrete pavers at the Natural History Museum of Utah, seen here on May 5, 2025, allow stormwater to infiltrate on\u2011site, naturally filtering pollutants and recharging groundwater \u2014 part of the museum\u2019s sustainable design.<\/p>\n One approach to addressing these challenges is Low Impact Development (LID) \u2014 a method of managing urban runoff that\u2019s designed to mimic natural processes. <\/p>\n Some solutions blend into the landscape, like the vegetated swales\u2014 shallow, sloped, plant-lined channels often found along roads, parking lots, and parks \u2014 that absorb and filter runoff before it enters storm drains. <\/p>\n Others work beneath the surface, such as underground stormwater storage systems that temporarily hold stormwater, preventing flooding and reducing pollution. <\/p>\n 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.<\/p>\n 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\u2019s bioretention rain garden filters pollutants from stormwater, and the University of Utah\u2019s Landscape Lab slows and treats runoff with bioswales before it reaches Red Butte Creek.<\/p>\n (Chris Samuels | The Salt Lake Tribune) Riverton environmental engineer Tom Beesley shows an example of an urban swale in Riverton, Friday, July 18, 2025. The recessed park strip is intended to capture stormwater and pollution before it enters the city\u2019s sewage.<\/p>\n Tom Beesley, flood control engineer at Riverton City, is pushing for more swales in new developments<\/a>. <\/p>\n \u201cBefore 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,\u201d Beesley said. \u201cAnd it was trapped in the sagebrush and the grasses and didn\u2019t end up in the Jordan River in huge volumes. So it wasn\u2019t a problem because mother nature managed that pollution with vegetation.\u201d<\/p>\n 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.<\/p>\n 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 \u201cout of sight, out of mind\u201d when it rushes down into storm drains, Beesley said. <\/p>\n \u201cBy putting pollution back into swales we actually mimic Mother Nature as much as we possibly can,\u201d Beesley said. \u201cWhich I think is the only way we\u2019re going to keep water resources, aboveground and below ground, clean.\u201d<\/p>\n Environmental design slows water to the Great Salt Lake<\/b><\/p>\n (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.<\/p>\n But LID also introduces a challenge: while improving water quality, it reduces the amount of water that eventually makes it to the lake because the water seeps into the ground or is evaporated from the soil and transpired by plants.<\/p>\n According to a 2023 study<\/a> 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\u2019t used in future developments \u2014 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. <\/p>\n