What is a Stormwater Treatment Area?
Stormwater treatment areas (STAs) are constructed living wetlands divided into flow-through treatment cells that remove nutrients from agricultural and urban runoff water prior to discharging to our creeks and river. The nutrients are consumed through plant growth, and captured by accumulation of dead plant material that is slowly converted to a layer of peat soil. The flow-through system of the STA cleanses the water and assists the county in meeting state mandated water quality targets.
How it works: Agricultural and urban runoff water containing excess phosphorus and nitrogen is diverted to STAs that have been planted with a selection of native wetland vegetation with useful characteristics for water purification. These plants species absorb phosphorus and nitrogen, storing it in their roots, stems and leaves. In addition to filtering water, STAs serve as a storage basin to ensure water availability in times of drought, and provide valuable habitat for wildlife species.