Drainage and Flood Prevention
DRAINAGE AND FLOOD PROTECTION
Enhancing Our Flood Resilience
With climate change, rainfall events could increase in frequency and intensity. PUB, Singapore’s National Water Agency adopts a four-pronged approach towards flood management which comprises (1) Drainage Infrastructure, (2) Legislation, (3) Flood Response Operations and (4) Community Resilience
Drainage Infrastructure
PUB has an extensive drainage system comprising 8,000km of drains, rivers, and canals that channel rainwater to our reservoirs or the sea. Significant investments have been made over the decades to upgrade drainage infrastructure. However, it may not always be feasible or cost-effective to build bigger drains and infrastructure to cater to every extreme rainfall scenario due to Singapore’s land constraints. Hence, PUB also adopts holistic stormwater management through the “Source-Pathway-Receptor” approach. Beyond drainage upgrading (i.e. “Pathway” solutions), stormwater is also managed where it falls (i.e. through “Source” solutions such as on-site detention tanks in buildings) and at the areas where floodwaters may flow (i.e. through “Receptor” measures such as flood barriers, and minimum crest and platform levels to be incorporated by developments).
Source-Pathway-Receptor Approach
Source: PUB, Singapore’s National Water Agency
Through this approach, stormwater management is addressed across all parts of the drainage system, with building owners and developers playing a role in managing flood risks and the potential impact on their developments.
Legislation
Developments must adhere to requirements such as minimum crest and platform levels to minimise flood risks. Amendments to the Sewerage and Drainage Act were also passed in November 2024 to ensure that owners and developers carry out proper maintenance of their stormwater drainage systems and flood protection measures within their premises.
Flood Response Operations
PUB’s comprehensive suite of flood response measures consist of rainfall monitoring and forecasting, early warning and ground deployment of Quick Response Teams to ensure public safety.
Community Resilience
Community resilience will need to be strengthened by creating awareness of flood risks, fostering acceptance that flooding could occur from time to time and motivating communities to take action to plan and protect against flooding. Everyone has a role to play in ensuring Singapore’s flood resilience. Through its timely forecasting and warning service, PUB provides information to the community to help them better prepare and respond to flood incidents. PUB engages residents and businesses in flood-prone areas on flood risks, distributes flood protection devices and organises community exercises to enhance flood preparedness in these premises.