Effectiveness of nitrogen removal using urban wetlands – summary report

This report summarises the Monash University research outcomes for Project B2.2/2.3—Protection and restoration of urban freshwater ecosystems: informing management and planning.

As urban development increases, constructed wetlands are becoming more common as tools for reducing nitrogen and other pollutant loads, but their effectiveness is variable and limited. In particular, information about temporal changes and the important processes involved in removal is limited, which makes effectively managing nitrogen loads difficult.

This study highlights the importance of gathering a ‘whole picture’ view of wetland function. From our results, it is unclear whether constructed wetlands effectively remove a significant amount of nitrogen from stormwater over time, without studying nitrogen removal efficiency over a wetland’s lifetime. In addition, more research is needed into how wetlands behave during event conditions when a significant portion of the annual nitrogen load is put into the system.