Oct. 8, 2026
As The Dawes Arboretum begins construction on a new Welcome Center, it is maximizing multiple natural processes. Although it won’t be visual until much further into the construction process, The Arboretum is using a natural drainage solution called a bioswale to encourage biodiversity amongst urban development.
A bioswale is a natural stormwater management garden that moves water from one point to another. It is a linear natural filtration system for pollutants. The surrounding plants in the bioswale help break pollutant bonds and compounds down by turning them into smaller molecules and ingesting them.
It’s built by laying a V-shaped layer of rock with sand in the middle. It’s very similar to a rock filtration system in an aquarium.
The bioswale is planted with native, local flora because local flora tends to have deeper root systems that can intake more water than a turf can, therefore slowing down the movement of storm water.
Without solutions like a bioswale, water spilling off a roof or overflow from parking lots can overload traditional drainage pipes, causing erosion. The bioswale slows down the water and provides water filtration, which allows time for pollutants to be filtered out before the water reaches its end point.
It’s important to filter pollutants because the end point could be reservoirs used for drinking water. Pollutants could also land in lakes, rivers or oceans, affecting all organisms that live in those spaces.
“Without having a permeable pavement or retention basin, runoff is an environmental issue. With that amount of runoff, the ground is so saturated, and it’s like, ‘I can’t take this anymore.’ That’s why building these [bioswales] are so important. It makes the water accessible to plants and ecosystems as opposed to running off, being a problem and overwhelming our storm water systems,” said Shannon Barnette, Horticulture Manager at Dawes.
Barnette will oversee planting the bioswale adjacent to the new Welcome Center. She said that visitors will be able to see the plants from the deck of the new Welcome Center.
The first step in creating the bioswale is soil testing. Then light conditions like sun and shade need evaluated so the best plants can be selected for the site conditions.
The Arboretum is using processes like these to stay mindful of the surrounding landscape and potential environmental impacts. To keep up to date with the New Welcome Center, read here.