Wetlands are key to storing and treating stormwater
As part of the permitting process, the Tennessee Department of Environment and Conservation mandates the City of Kingsport offer educational and outreach activities regarding stormwater, the city’s various control measures and why those measures are important to the general public.
The following article discusses stormwater wetlands and how they are used to support aquatic plants.
Stormwater wetlands (or constructed wetlands) are a type of Stormwater Control Measure (SCM) built for the purpose of storing and treating stormwater run-off. Pollutant removal is achieved through settling and uptake by marsh vegetation.
Stormwater wetlands are designed with a shallow permanent pool to support aquatic plants. Most stormwater wetlands have the same basic components to help them function properly, including:
- Inlets – ditches or pipes that convey drainage into the wetland from the surrounding area during a rain.
- Forebay – shallow depression that catches trash, debris and sediment to keep it out of the main basin.
- Main Basin –collects and retains stormwater and has marsh vegetation to filter water pollution.
- Embankments –sides of the pond, usually vegetated to prevent erosion.
- Outlet Structure – allows water to exit the basin in a controlled manner.
- Emergency Spillway – allows water to safely overflow the top of a dam.
Stormwater wetlands may be inspected by the local municipality to ensure they are functioning correctly. However, all maintenance is the responsibility of the property owner.
In order for the stormwater wetland to work efficiently, marsh plants should kept healthy and watered in times of drought; and invasive plants, shrubs and trees should be removed. All trash, debris and sediment should be removed from the forebay at regular intervals. Any areas of erosion on the side slopes should be repaired.
The outlet structure should also be free of mud, debris and trash. Inlet pipes should be checked for clogs and inlet ditches should be checked for erosion. The basin should be observed during and after rain events to ensure it is functioning properly.
If you have a concern about a specific stormwater wetland in Kingsport, you may call Water Services at 423-229-9454. You can also report any possible issues by using the ConnectKingsport app.
