Water Quality Swales

11/11/25

“How can we treat stormwater runoff using vegetated open channels?”

Stormwater runoff can carry pollution into nearby water bodies. Government bodies may require building and construction operators to slow down and treat stormwater pollution loads coming from their properties. So what’s one way people can accomplish this without using a complicated system? Well, we know that vegetation naturally slows down water and absorbs pollutants while providing infiltration potential. We also know that directing water through a channel allows people to manage the direction of flow. So what if we were to create landscaped vegetation channels that can slow down water, allowing for sediments to settle, infiltration to occur, and pollutants/nutrients to get trapped? Well, this is the basis for Water Quality Swales. Water quality swale slopes are typically at a gentle 3 feet horizontal by 1 foot vertical slope to avoid quick channel flow and maximize surface area for filtration. Land-use managers should install water quality swales before impervious surfaces to enable proper infiltration.

Image credit: https://megamanual.geosyntec.com/