The University of Tennessee (UT) is collaborating with the City of Knoxville and a local nonprofit partner to plant trees where they’re needed most and cultivate greater awareness of urban forestry careers.
The USDA Forest Service awarded UT $2.6 million to increase tree canopy coverage, reduce stormwater runoff, mitigate extreme heat, and bring ecosystem services to communities in East Knoxville where the physical landscape combines an abundance of heat-retaining surfaces with a lack of canopied vegetation. To achieve that suite of benefits, the UT team is installing gravel-tree stormwater systems (GTSS). GTSS functions similarly to rain gardens and other bioretention methods—yet costs roughly one-third the price.
Between 2024 and 2029, UT’s team will install and monitor approximately 40 GTSS and provide accompanying public education and workforce development. The project aligns with Knoxville’s urban forest master plan and complements other federally funded urban forestry initiatives within the city.
“GTSS will provide much-needed shade and evaporative cooling, capture water to help mitigate flooding during heavy rain, filter runoff before it’s discharged into surface water, and increase exposure to nature,” said Civil and Environmental Engineering Professor Jon Hathaway. “These benefits can add up to positive impacts on quality of life and community well-being.”
Hathaway is leading UT’s team alongside Professor of Urban Forestry Sharon Jean-Philippe, Professor of Geography and Sustainability Kelsey Ellis, and University of Missouri Assistant Professor of Social Work Jennifer First.
GTSS was originally conceived by Hathaway’s long-standing collaborator Eric Kuehler, arborist for Nashville’s Metro Water Services and former Forest Service staff member. The two demonstrated GTSS in collaboration with additional UT faculty and the City of Knoxville Urban Forestry Division between 2016 and 2019.
“Our preliminary assessment showed GTSS functioned well,” Hathaway said. “The current project enables us to scale up installation and collect data to continue improving GTSS design.”
The team will measure data points including water movement, retention, and quality. They’ll also identify multiple tree species, including native fruit trees, that can thrive in the GTSS setting.
“Ultimately, we aim to demonstrate GTSS is a viable stormwater management practice and develop a formal, publicly posted design specification document that other communities can use to efficiently, effectively install their own,” Hathaway said.
As of October 2025, the first four systems have been installed—sited and designed by UT, constructed by local contractors. UT and nonprofit partner SEEED (Socially Equal Energy Efficient Development) are hosting monthly community workshops about trees and urban stormwater infrastructure. The project’s first paid intern, a graduate of SEEED’s Career Readiness Program, is working alongside Knoxville’s professional urban foresters.
The UT team will soon launch the project’s classroom component: collaborating with local educators to teach K-12 students about watersheds, trees, and urban forestry.
“Bringing engineers, tree experts, teachers, and community organizations together is how we develop better products and outcomes,” Hathaway said. “This interdisciplinary approach aligns with the Institute for a Secure & Sustainable Environment’s mission and UT’s land-grant mission. We’re creating and sharing knowledge for implementation. We’re introducing people to career paths. There’s great potential for lasting impact.”
Author
Meghan McDonald