Clemson Extension offers planter boxes to soak up urban runoff in Florence, Darlington County
FLORENCE — Simple wooden boxes of plants and flowers are providing more than eye-catching landscape in downtown Florence.
These planter boxes installed at the bases of downspouts are filtering rainwater as it drains off rooftops and preventing stormwater runoff from polluting downstream waterways with bacteria, oils, greases, heavy metals, antifreeze and other toxins.
Clemson University Cooperative Extension Service water resources agent Terasa Lott is working with city and county officials to install the planter boxes at the bases of downspouts on buildings in the downtown district. The project serves as a low-cost example for other communities in South Carolina to emulate, and a new community grants program from Extension’s Carolina Clear program is making the boxes available to businesses, churches or apartment complexes in Florence and Darlington counties.
“Normally we think of rain as a very positive thing, but in urban landscapes, the associated runoff can be a very large contributor to water pollution,” Lott said. “Instead of allowing the water to flow out of the gutter and into our storm drain system, we can channel it into a planter box, which has a special soil media designed to absorb and filter that runoff.”
The city of Florence worked with private property owners to install the planter boxes at locations downtown, said city planner Jerry Dudley. Carolina Clear assisted on the project.
“In our urban environment, there is a lot of impervious surface, so anything we the city can do to capture some of the water with these planter boxes to remove some pollutants is a potential benefit to water quality in the downtown area and our watershed as a whole,” he said.
Carolina Clear is providing these downspout planter boxes to educate and involve the community in stormwater management, demonstrating that stormwater can be mitigated in the most difficult of environments: urban landscapes.
These boxes are roughly three feet tall and two to three feet wide, though they may be designed in various shapes and sizes. They are made of rough-cut cedar boards and installed at the base of a downspout that channels water from the roof. The downspout includes an adjustable metal channel that can divert water away from the box in the event of a major storm that could flood and damage the box.
The interior of the box is lined to prevent the wood from rotting, and a layer of rocks at the box bottom assists with drainage and increases volume storage. The soil is a mix of compost, sand and topsoil to maximize water absorption and infiltration, Lott said. The boxes include plants that can survive in both wet and dry soils, Lott said. In one box, Lott planted an evergreen plant called juncus and purple cone flower, which attracts butterflies and other pollinators.
Carolina Clear and the Florence Darlington Stormwater Consortium have installed three boxes in Florence to demonstrate and improve local water quality. Extension’s Carolina Clear program is making the boxes available to other property owners through a local pilot of a new community grants program. The community grants are open to highly visible businesses, churches or apartment complexes in Florence and Darlington counties that are interested in showcasing a commitment to reducing runoff and protecting water quality. Applications to receive planter boxes should be submitted online by May 1.
“Stormwater management can look good,” said Katie Buckley, Carolina Clear director. “Green infrastructure is being used across the country and right in Florence to create natural places and use vegetation to solve stormwater problems. This planter box is an opportunity to use vegetation at the very small scale to beautify downtown and remove stormwater volume. The results are made greater by greater participation, and we look forward to helping our partner communities beautify and protect through this effort.”
Carolina Clear works alongside more than 38 South Carolina municipalities and counties, as well as several dozen partners, including higher education institutions, state agencies, nonprofits and schools. It offers information and training in rainwater harvesting, rain garden and downspout planter installation, shoreline restoration, stormwater pond management and more.