By LYDIA BERGLAR
When paving a parking lot in Jenkins Park came up on the City of Trenton’s SPLOST project list, Limestone Valley RC&D saw an opportunity to address erosion and pollution caused by water runoff.
“This pavement that we’re putting down is permeable, meaning that as the water hits it, it can soak into the asphalt,” said Stephen Bontekoe, executive director of Limestone Valley Resource Conservation & Development Council. “This is cutting edge.”
Because permeable pavement is more expensive than typical pavement, these additional expenses are covered through the nonpoint water pollution 319(h) program: federal funds, administered by the state, and implemented on the local level by non-profits such as Limestone Valley.
“Point source pollution,” Bontekoe explained, “is like a pipe coming out of a factory that I can point to. Non-point is like runoff from roads. All of our cars drip oil, and there’s plastic and litter that goes to the lowest point, which is often streams and such. One of Limestone Valley’s goals is to reduce nonpoint pollution.”
He continued, “Fast-moving water tends to cause erosion. When you have solid surfaces, like paved lots, water picks up speed where it would otherwise be soaking into the soil. Best management practices to address this issue include green infrastructure, which uses the vegetation and soil to capture and slow down water.”
Bontekoe refers to human-made structures and surfaces as “the built environment.” While the built environment can inadvertently create issues in the natural environment, nature can also be used to counterbalance the built environment. “Often, the solutions are natural solutions, but we have to go in and build them.”
Bontekoe noted one example from a town in the northeastern United States. “They had a flooding problem, so they carved out a large swath of land as a wetland. This land had historically been a wetland, but it had been transitioned into other uses. Wetlands serve as a sponge, so reestablishing the wetland soaked up the water and held it back so it was released slower to their river. The solution to their flooding problem was a natural solution that had some design behind it.”
One local resident also implemented a similar idea in his own backyard. Bontekoe recalled, “A guy asked me about an issue he was having with the gutters at his house. The water was coming out of his downspout and scouring his yard. He knew he could put in a pipe that would hold water, but it’d kill his grass there. We were able to transfer the rain garden concept to his backyard. In 15 minutes, he and I walked through how he could put in a nice little planter bed. He spent about $50 at the hardware store, dug a small garden, filled it with a few bags of pea gravel, put in some topsoil, and added plants that can handle both wet and dry.”
Here at Jenkins Park, the permeable asphalt will look and feel like any other lot. It works by having a greater pore space and a rock chamber underneath that collects water and uses a pipe system to deposit it in the rain garden. The rain garden then uses natural vegetation to slow the flow of the water as it enters the creek.
Bontekoe noted that city planners from Rome, Ga. heard about this project and visited Trenton to see it for themselves. He said, “Rome is interested in moving the needle forward on best management practices.”
He also noted that the City of Lookout Mountain recently installed a permeable pavement parking lot.
Bontekoe believes the extra expense for this paving method is a long-term investment. “If we’re spending less money later on repairing structures because we were able to slow water down, it’s a net gain. If we have healthier fish populations because there’s less sediment in the water caused by erosion, that’s a benefit for the ecosystem. It’s also a benefit for the bridge pylons that won’t be washing out.”
Completion of the project is dependent on the weather, but Bontekoe expects it to be completed soon.
Regarding future permeable paving in Dade County, Bontekoe said, “It depends on the appetite of the community and funding. We’ll continue to pursue funding opportunities.”