In the heart of Singapore’s urban landscape, a quiet revolution is taking place, one that could reshape how cities worldwide manage stormwater and bolster biodiversity. At the forefront of this green infrastructure movement are rain gardens, and a recent study led by Lina Altoaimi from the National University of Singapore is shedding light on their long-term impacts and the challenges they face.
Rain gardens, designed to mimic natural processes to manage stormwater, are becoming a staple in urban areas. However, their long-term performance and effects on biodiversity have remained underexplored—until now. Altoaimi and her team compared two rain gardens in Singapore: one in the Central Singapore neighbourhood of Potong Pasir, managed by a local town council, and another in the Jurong Lake Gardens, managed by the National Parks. Their findings, published in the *Journal of Design for Resilience in Architecture and Planning* (which translates to *Journal of Design for Resilience in Architecture and Urban Planning*), offer a roadmap for improving these green spaces.
The study revealed that rain gardens face common challenges, including poor maintenance, aesthetic disengagement, and design flaws. “Improper maintenance and design can lead to functional and aesthetic degradation, ultimately reducing the lifespan and effectiveness of rain gardens,” Altoaimi explained. To tackle these issues, the research provides comprehensive design and maintenance suggestions, focusing on the four key functions of a rain garden: sedimentation, filtration, infiltration, and bioretention.
One of the study’s key insights is the importance of integrating nature-based solutions with existing grey infrastructure maintenance protocols. By doing so, cities can extend the lifespan of rain gardens, ensuring they continue to provide long-term benefits such as effective stormwater management and habitat creation for local biodiversity. The research also highlights the potential of tree planting configurations and the use of groundcover to reduce surface temperatures, enhancing both the ecological and aesthetic functions of these spaces.
For the energy sector, the implications are significant. As cities increasingly prioritize sustainability, green infrastructure like rain gardens can play a crucial role in reducing urban heat islands and improving energy efficiency in buildings. By managing stormwater naturally, these gardens can also reduce the strain on energy-intensive drainage systems, leading to cost savings and environmental benefits.
Altoaimi’s research underscores the need for a holistic approach to urban planning, one that balances functionality with aesthetics. “A well-designed and maintained rain garden can be a beautiful, functional asset to any urban landscape,” she said. As cities around the world grapple with the challenges of urbanization and climate change, the insights from this study could shape the future of green infrastructure, making our urban environments more resilient and sustainable.