Staff Report
SAN MARCOS — Texas State University researcher Sangchul Hwang, Ph.D., P.E., is leading a city of Kyle-funded project that will deploy floating wetlands to improve water quality in Lake Kyle. The project will test whether this nature-based system can help protect the surrounding Plum Creek Watershed, the land that drains rain and runoff into Plum Creek and connected waterways.
Hwang, a professor of civil and environmental engineering in TXST’s Ingram School of Engineering, received a $457,000 grant from the city of Kyle for the three-year project, “In-Reservoir Water Quality Management with Floating Wetlands,” according to a news release.
The research comes as Kyle continues to grow rapidly. U.S. Census Bureau estimates show the city’s population jumped by 53% from 2020 to 2025, reaching 69,917 residents. Continued development can increase stormwater runoff, which can carry sediment, nutrients, bacteria and other pollutants into local waterways.
Lake Kyle is a 12.5-acre recreational lake, where residents can fish, walk trails, picnic and spend time outdoors. Cleaner water can support recreation, aquatic habitat and waterways beyond Kyle, as Plum Creek flows through Hays and Caldwell counties before joining the San Marcos River.
“This grant represents recognition and trust from the community that our research can contribute to addressing real-world environmental and water challenges,” Hwang said. “It provides an opportunity to translate our academic research into practical solutions that can directly benefit the community.”
Floating wetlands are buoyant platforms planted with wetland vegetation. Their roots dangle into the water, where they absorb nutrients, such as nitrogen and phosphorus, and host microorganisms that break down pollutants and trap suspended particles.
Unlike traditional treatment methods that rely primarily on mechanical equipment or chemicals, floating wetlands harness plants, roots and natural processes to clean the water. They can be anchored directly in lakes and ponds without requiring additional land or major infrastructure.
Hwang’s team is monitoring Lake Kyle to measure current water quality conditions and pinpoint potential pollution sources. The researchers have already tested a small-scale floating wetland in the lab and are now testing a larger version under conditions that better match Lake Kyle, continued the release. The team expects to launch the floating wetlands in spring 2027, followed by continued monitoring to measure how well they work.
“Our research goes beyond the laboratory,” Hwang said. “Rather, we are working on-site and testing a nature-based solution that could have practical value for the community.”
As part of its baseline monitoring, the research will also screen for contaminants of emerging concern, including per- and polyfluoroalkyl substances (PFAS) — often called “forever chemicals” — although PFAS have not been identified as a current water quality problem in Lake Kyle or the Plum Creek Watershed.
Hwang is the project’s sole principal investigator, leading a team of doctoral, graduate and undergraduate students from his HEDGE Research Group. The student team includes:
• Pranesha Dangol, a civil engineering undergraduate student who focuses on water quality monitoring and analysis.
• Prajwal Bhattarai, a civil engineering doctoral student who works on the design and construction of the floating wetlands.
• Bibek Paudel, a computer science undergraduate student who supports data analytics.
The project will give Kyle clearer data and new tools to protect local water resources as the community grows, while providing a model other cities can adapt to their own water-quality challenges, said the release. By pairing natural processes with existing treatment and stormwater practices, the research could help shape a more sustainable approach to managing water across Texas and beyond.
