Low impact development (LID) technology has been recently applied for the treatment of nonpoint source pollutants.
Rain garden is one of the widely used LIDs since it utilizes various mechanisms such as biological and physico-chemical
treatment to reduce pollutants. However, problem such as clogging has been one of the issues encountered by the rain
garden that do not undergo constant maintenance. Therefore, this research was conducted to develop and determine the
component arrangement of a rain garden system for a more efficient volume and pollutant reduction. Two hybrid rain
garden systems having different characteristics were developed and evaluated to determine the optimum design and
arrangement of the system. The results showed that the components arranged in a series manner showed a volume reduction
of 93% and a pollutant reduction efficiency of approximately 99%, 93% and 95% was observed for particulates, nutrients
and heavy metals, respectively. While when the system is connected in a combined series-parallel, the volume and average
pollutant reduction efficiency for the TSS, nutrients and heavy metals are 65%, 94%, 80% and 85%, respectively. Moreover,
the component arrangement in the order of sedimentation tank, infiltration tank and plant bed exhibited a high pollutant
reduction efficiency compared when the infiltration tank and plant bed were interchanged. The findings of this research
will help in the further development and optimization of rain garden systems.