Measures to Mitigate against Flooding Given Inclement Weather Due To Indian Ocean Dipole

Ms Hazel Poa asked the Minister for Sustainability and the Environment whether she can provide an update on the flood management measures and early warning system in view of the recent flooding.

Mr Seah Kian Peng asked the Minister for Sustainability and the Environment (a) whether the Ministry has conducted a comprehensive review of areas that are susceptible to flash flood situations like what was experienced on the morning of Friday, 20 August 2021; and (b) what plans are being made to mitigate such possibilities from recurring going forward.

Thank you. PUB has invested almost $2 billion on drainage works in the last decade and reduced Singapore’s flood-prone areas from 3,200 hectares in the 1970s to 28 hectares today. PUB will continue to monitor these flood-prone areas closely. Another $1.4 billion will be invested over the next five years on drainage improvement works. It is, however, not practical to expand all 8,000-plus kilometres of our drains and flood protection infrastructure to accommodate every extreme rainfall event, as this would require massive land take and much higher costs.

Flash floods arising from intense rainfall occur in limited areas and are transient – most will subside within 30 minutes, given our extensive drainage system. Moreover, PUB deploys more immediate and practical measures to protect our properties against flash floods, including portable flood barriers that can be installed at doorways or erected on roads and pavements. These flood barriers protect residents and businesses against flash floods and minimise potential damage to their premises.

PUB is using technology to better predict and respond to floods. PUB will complete enhancements to its rainfall forecasting capability by first quarter of 2022. This will help forecast locations which will face heavy rainfall, issue earlier public alerts and enable early deployment of portable flood barriers in areas at risk of flash floods. Coupled with an extensive network of water level sensors and CCTVs installed at flood-prone areas, PUB’s Quick Response Team can also be deployed on site faster and assist premises owners to set up flood barriers, if needed. Information on floods and road closures is communicated to the public promptly through radio broadcasts, news media, myENV Mobile App, PUB Facebook and Twitter, as well as LTA’s Expressway Monitoring Advisory System. SMS alerts are also sent to those who have registered to receive flood warnings.

These measures will also help build preparedness to extreme weather events and strengthen community resilience, as we check weather advisories and warnings and adjust our daily schedules accordingly. I encourage members of the public to subscribe to NEA’s and PUB’s SMS alerts.

PUB will continue to strengthen our forecasting and sensing capabilities and implement cost-effective measures to minimise flood risks. However, PUB cannot minimise flood risks on its own. Building owners must ensure that flood prevention measures in their developments remain effective. Contractors must also implement proper flood prevention measures at their worksites. We have seen cases of contractors failing to do so, resulting in floods in their locations.

This brings me to the flash flood incident that occurred on 20 August 2021. This flash flood was reported at the junction of Tampines Avenue 10 and Pasir Ris Drive 12 towards TPE entrance at around 8.00 am. PUB’s Quick Response Team was immediately deployed to assist drivers and pedestrians, together with SCDF and Police. PUB also issued advisories to motorists and members of the public to avoid the area.

This location is not a flood-prone area and the drainage system is more than adequate to cope with the rainfall intensity experienced on 20 August 2021. PUB’s investigations found that the contractor carrying out road widening works along Tampines Avenue 10 had altered the public drainage system there without PUB’s approval. As a result, storm water could not discharge effectively into downstream Sungei Api Api.

PUB does not condone such illegal works and will be pressing charges against the contractor under the Sewerage and Drainage Act.

Under the Sewerage and Drainage Act, no one can carry out any works to alter our storm water drainage system without PUB’s approval. PUB also requires contractors working in the vicinity of any watercourse to put in place measures to prevent construction materials from falling and choking up the drainage system. PUB takes a serious view of all works that affect our public drainage system. We have reminded all contractors to comply with the requirements and will take enforcement action against errant contractors.

Thank you, Mdm Deputy Speaker. Just a few quick questions. We know that we have an increasing number of roadworks, infrastructure works for the next few years. Do we need to toughen up our laws so that contractors know that they will be in serious trouble if they do not comply with the regulations?

The second one is: how are we coordinating from an inter-agency perspective so that all agencies, if they are part of the roadworks, can coordinate so that we have less of such occurrences like the one in Tampines in future?

Mdm Deputy Speaker, there is already coordination between PUB and LTA. In most cases, for major roadworks, such as for MRT stations, there has been close coordination of the work that is progressing and also the preventive measures that are being taken. But, from time to time, we do have such unauthorised alterations and also blockage in the drainage; sometimes, it is intentional or, sometimes, it is actually because of poor housekeeping. It happens from time to time.

So, we do have to step up and look at how we can improve the enforcement and monitoring measures. We will review our measures from time to time to see if they are adequately preventive.