Floating Treatment Wetlands (FTWs) combine natural biological processes with engineered stormwater design. The plants that grow in these systems remove pollutants from water bodies such as lakes, ponds, stormwater basins, and canals.
These natural systems facilitate filtration, nutrient reduction, and sedimentation. Effectively treating incoming stormwater flows, Floating Treatment Wetlands provide environments to enhance each of these removal pathways.
Floating treatment wetlands (FTWs) supercharge the performance of traditional constructed wetlands. The floating nature of the wetland structure encourages strong plant growth by providing optimal growing conditions.
In traditional wetlands, roots are buried in the soil on the foreshore. In comparison, FTW systems float on the surface of the water, which allows roots to grow beneath each module and extend into the water column. This network of roots and attached biofilm provides large surface areas for stormwater treatment.
Floating Treatment Wetlands use physical, biochemical, and microbiological processes to remove particulates and dissolved pollutants from stormwater. As incoming flows reach the network of roots and biofilm, dissolved nutrients are used by the plant as a food source and processed by microorganisms. Particulate nutrients and sediment are slowed and fall to the bottom of the water body.
Consequently, Floating Treatment Wetlands reduces the asset footprint required to meet water quality objectives by up to 60% compared to traditional constructed wetlands.
FTWs are often installed in combination with primary treatment assets (Gross Pollutant Traps) to minimise the amount of litter, debris, and sediment entering the waterbody from nearby catchments. This reduces the impacts of high pollutant loads on wetland environments, reduces impacts on plant growth, and lowers maintenance requirements.