Pilot project at Universiti Sains Malaysia shows how calibrating eWater MUSIC™ unlocks stormwater performance predictions in tropical climates.
eWater Group supports a community of practice approach where current and future generations of water experts, students and professionals can come together to explore how our tools and thinking can be challenged to help policymakers, governments and private sector address the challenges facing our communities now and into the future.
We welcomed an innovative study conducted at Universiti Sains Malaysia (USM) in Penang, Malaysia, that explored how eWater’s MUSIC software, widely used across Australia for stormwater modelling, can be a highly effective in tropical urban environments, when locally calibrated.
With urbanisation accelerating across Southeast Asia, cities face mounting challenges from polluted stormwater runoff. The Malaysian research team – Khee Ling Wong, Hui Weng Goh, Chun Kiat Chang, Siti Fairuz Juiani, and Nor Azazi Zakaria – set out to test MUSIC’s effectiveness in simulating the performance of bioretention systems, a key green infrastructure solution that filters runoff using vegetation and engineered soils.
The study focused on a pilot bioretention site on USM’s engineering campus, exposed to real tropical conditions: intense rainfall, high temperatures, and mixed urban pollutants. Using real runoff collected from nearby urban areas, the team measured flow and pollutant removal over multiple weeks (see image below).
Initial simulations using MUSIC’s default settings underestimated pollutant loads and overestimated treatment performance. But after a two-stage calibration process, adjusting impervious area assumptions and first-order decay model parameters, the model aligned closely with real-world results.
P1(no vegetation), P2 (single species) and p3 (multiple species)
This study reinforces eWater MUSIC’s flexibility.
It shows that with the right data; we can use MUSIC to reliably model bioretention systems in Malaysia and other tropical regions.
Among the key findings:
- Calibrated MUSIC simulations matched observed reductions in total suspended solids (TSS), nitrogen (TN), and phosphorus (TP) with high accuracy.
- The model’s performance ratings were ‘very good’ for TSS and TN, and ‘good’ for TP.
- Flow reduction estimates were also reasonable, though evapotranspiration from tropical vegetation remains a modelling limitation.
Plan View & Cross Section of USM Bioretention Pilot Site
The research supports MUSIC’s broader international relevance, particularly in regions where stormwater regulations are evolving. The findings also inform local design standards like Malaysia’s Urban Stormwater Management Manual (MSMA).
The study confirms that when calibrated to reflect local runoff characteristics and treatment conditions, eWater MUSIC can reliably model bioretention performance in tropical climate, demonstrating that it can be used in a wide range of contexts and environmental settings, Australian and international.
The study, funded by Malaysia’s Ministry of Higher Education, highlights the importance of pairing field research with data-driven modelling to design resilient, sustainable urban drainage systems.
We thank the Universiti Sains Malaysia for taking the opportunity to explore the possibilities for eWater MUSIC™ for Australia and internationally.
This study was funded and supported by the Government of Malaysia through the Higher Institution Centre of Excellence Program (HICoE) (Grant no. A305-LR-AKH001-0004403901-0000) for the niche area of sustainable stormwater management.
Learn More:
- Full Study: Bioretention Model for Urban Runoff Treatment in a Tropical Climate
- Explore MUSIC by eWater: www.ewater.org.au
Address
Support and Training
