Singapore Expands Waterway Capacity 30% with Bioengineering

Integrated Flood Control and Public Space

Singapore's Active, Beautiful, Clean Waters (ABC Waters) Programme, initiated in 2006, transforms urban waterways into both public spaces and efficient drainage infrastructure. A notable example is the redesign of a 2.7-kilometer stretch of the Kallang River at Bishan–Ang Mo Kio Park.

This project converted a former concrete canal into a naturalized river, allowing the surrounding park to manage water flows during heavy rainfall. The design integrates grass, planting, and pathways with the river's edge, enabling the landscape to function as a flood conveyance area beyond the narrower channel's capacity. This approach maintains drainage engineering while expanding the role of adjacent land.

Capacity Expansion at Sungei Tampines

Further demonstrating this strategy, drainage improvements along a 1.4-kilometer section of Sungei Tampines in 2022 increased its stormwater conveyance capacity by 30 percent. This involved widening the waterway by up to 4.5 meters and deepening it by 0.5 meters. Concurrently, approximately one kilometer of one bank was naturalized using soil bioengineering techniques.

The project also introduced a cantilevered park connector, lookout decks, and a bridge, enhancing public access along the waterway while maintaining its primary function in stormwater management.

Runoff Treatment and Ecological Features

At Sungei Ulu Pandan, the program incorporates landscape features designed to treat runoff before it enters the canal. This includes vegetated swales to guide runoff and remove larger sediments, sedimentation basins for particle settlement, and cleansing biotopes that use plants and soil media to filter pollutants and absorb nutrients.

Shallow, planted habitat cells along the canal edges also provide shelter for wildlife. These interventions were implemented in phases, with an initial 600-meter section completed in 2013 and a further 1.9 kilometers finished in 2022.

Research evaluating Singapore's ABC Waters Programme indicates good performance in removing suspended particles, though nutrient removal consistency varies with site conditions and maintenance.

Design Considerations for Asian Urban Developments

This approach by Singapore's PUB offers a clear precedent for urban developers and architects across Asia. For projects integrating green infrastructure, specifying soil bioengineering solutions for bank stabilization and permeable landscaping materials becomes crucial.

Procurement teams should seek suppliers capable of providing specialized filtration media for cleansing biotopes and robust materials for cantilevered structures and public access points like lookout decks and bridges.

When planning similar urban waterway projects, designers should request performance data on suspended particle and nutrient removal for proposed biofiltration systems, considering the varying effectiveness found in research. This framework suggests a growing demand for materials that support both hydraulic engineering and ecological functions within public spaces.