MONITORING OF BIORETENTION SYSTEMS WITH ENGINEERED SOIL IN A TROPICAL CLIMATE

Abstract

One of Singapore’s water sources is local catchment. Thus, it is important to protect its stormwater runoff from non-point source pollution. However, urbanization and modern lifestyle will inevitably lead to deterioration in stormwater runoff quality. One possible solution is the implementation of bioretention systems. However, one hindrance is the depth of the subsoil pipe under such systems that may cause a problem for the treated water to be discharged into the surface drain by gravity if the drain is not deep enough. Variability in soil mix used as filter media also affects the performance of the system. Moreover, to facilitate ease of construction for bioretention system, modular systems will be helpful for easier design and to shorten the construction time. Thus, this project test-bedded and studied 3 bioretention systems, including a soak away rain garden and 2 modular bioretention systems (swale and tree), with engineered soil as the filter media.