PUB launches guidebook for building owners, developers to help flood-proof their premises

SINGAPORE – Install mobile flood barriers to keep flood waters out. Apply waterproof coatings to protect exteriors from water damage. Build raised entrances to increase thresholds above flood levels.

These are some measures landowners and industry professionals such as architects and engineers can find in a guidebook launched on June 18, which provides ideas on how to better protect their premises from floods.

The 99-page guidebook also provides a risk assessment tool to determine the likelihood and impact of floods, as well as appropriate actions to manage flood risk and prepare for flood scenarios.

Also in the guidebook are local case studies of how flood-proofing measures have been applied, as well as how to develop a flood response plan.

Launched by national water agency PUB, the Flood-Resilient Developments Guidebook is the first of its kind to enhance resilience against inland and coastal flooding in Singapore.

Rainfall is becoming more intense and unpredictable as the climate warms. By 2100, Singapore’s mean sea level is projected to rise by up to 1.15m. In the event of high tides and extreme events like storm surges, sea levels could rise by 5m, leading to coastal flooding.

Speaking at the Singapore Water Association (SWA) Southeast Asia Symposium on Coastal Protection on June 18, Senior Minister of State for Sustainability and the Environment Zaqy Mohamad said that achieving flood resilience is a shared responsibility.

Noting that 30 per cent of Singapore’s land could be chronically flooded or submerged if the nation does not act on sea-level rise, he said efforts like the Code of Practice on Coastal Protection, launched on June 17, put Singapore in a good position to adapt to sea-level rise.

“Achieving flood resilience more broadly requires everyone’s involvement,” he said. “Because flood resilience cannot be the responsibility of the Government alone. It has to reach every building, every estate, every household.”

The code of practice guides waterfront landowners and leaseholders on their obligations under a new law where occupants have to eventually build their own coastal protection measures.

The flood resilience guidebook was created by an 11-member Alliance for Action committee, which drew on members’ industry experience and expertise.

The committee also referred to similar guidebooks published in countries like the United States, the Netherlands and Japan.

While the measures in the guidebook are not mandatory, they help property owners and property management professionals to make more informed decisions on flood-proofing, based on their specific site characteristics and operational needs, said PUB.

Users can also find a list of flood protection measures along with factors for comparison, such as the costs, advantages and disadvantages, and operations and maintenance requirements, among others.

For example, flood bags – compact, super-absorbent “sandless” bags that help to prevent flood waters by blocking openings – are low-cost and easy to mobilise, but are ideal only for managing short-duration flooding and can leak under prolonged flooding.

The guidebook also highlights how some premises have integrated flood-resilient designs.

For example, Tanglin Mall has adopted both permanent and deployable solutions that could work in tandem. Located at the junction of Tanglin Road and Grange Road, it is surrounded by areas on higher ground such as Napier Road and Nassim Hill, and stormwater tends to converge during heavy rain.

Besides flood walls with integrated seating along the development’s perimeter, flip-up and slot-in flood barriers were also implemented in areas where permanent solutions were not feasible, to maintain barrier-free pedestrian and wheelchair-friendly access.

Sensors that monitor water levels and automatically trigger alerts have also been installed outside the mall’s entrance.

Another example is Funan, which is linked to the City Hall MRT station via an underpass. The shopping centre incorporates features like flood barriers in its basement, so it is isolated from the underpass if water enters its premises.

Ratna Delia Octaviana, associate director (urban planning) for water infrastructure and climate adaptation at consultancy firm Ramboll, which was not involved in the guidebook, said it makes flood resilience more accessible to building owners and developers.

“Flooding is often seen as something to be managed only by public infrastructure, but in a dense and highly urbanised city like Singapore, development-level resilience is also very important,” she said.

She said the type and age of a development will also affect how feasible the measures can be.

For new developments, many measures can be incorporated at the planning and design stage, she said. For existing buildings, retrofitting the measures may be more challenging due to space constraints, operational disruption, costs or heritage and accessibility considerations.

Noting that the guidebook does not suggest a one-size-fits-all solution, she said flood resilience does not always require major infrastructure works.

“Sometimes, targeted interventions at the most vulnerable points, such as basement entrances… or low-lying access points, can already make a meaningful difference,” she said.

“The key is to understand the site-specific risk first, then choose measures that are proportionate and practical.”

Besides the launch of the guidebook, it was also announced that PUB and the SWA Coastal Protection Chapter will develop a Skills and Competency Framework for the industry to build talent.

“A future-ready workforce is needed to plan, design and deliver effective coastal protection solutions,” said Zaqy.

He noted the need for specialised skillsets like flood modelling and coastal engineering, as well as operation and maintenance of flood protection systems.

The framework, to be completed in the first half of 2027, will guide the industry on essential skills, provide a structured pathway to relevant training and signal the need for workforce readiness as coastal protection works scale up.

Flood safety guide for landed homes and shophouses

How to prepare for a flood:

What to do when a flood is approaching: