This study, however, found that the linear section of the constructed wetland was only effective in reducing total phosphorus concentrations during low flow events. The vegetated drain and wet detention pond were the most effective areas in improving stormwater and reducing phosphorus concentrations. Soil analysis found that deposited wetland sediments are clay enriched, compared to the surrounding catchment soils. In terms of total phosphorus content, the ratio is almost 1 to 1, between wetland and in situ soils, which means that on average wetland sediments are not phosphorus enriched. Although research has examined water quality and determined sediment sources, little has been reported on the cycling of phosphorus within the wetland.
Results provide a basis for further modelling.