More accurate rainfall forecasts by early next year with system upgrade

PUB will then be better able to help owners of premises set up flood barriers: Grace Fu

An enhanced smart system to forecast rainfall here with greater accuracy will be completed by the first quarter of next year, boosting the Republic's suite of tools to respond more quickly to flash floods.

Minister for Sustainability and the Environment Grace Fu said in Parliament yesterday that enhancements to the rainfall monitoring and prediction system will help national water agency PUB better aid owners of premises in setting up flood barriers, among other things.

When the system was announced in January last year, it had three rainfall monitoring radars installed in the eastern, northern and western parts of Singapore.

Typically used in localised weather monitoring and air-traffic control, the radars collect data which is then fed into a system every two minutes to forecast the movement, growth and decay of rain clouds.

The current system is able to predict rainfall intensity 30 minutes in advance with an accuracy of 65 per cent. The enhancements will help to further improve its accuracy and increase radar coverage islandwide.

Other monitoring tools include PUB's network of water-level sensors and closed-circuit television cameras in flood-prone areas.

Ms Fu said information on floods and road closures is conveyed to motorists and the public through social media platforms and via the Land Transport Authority's Expressway Monitoring Advisory System.

"These measures will also help build preparedness for extreme weather events and strengthen community resilience, as we check weather advisories and warnings and adjust our daily schedules accordingly," she said.

Her comments come in the wake of a number of floods in Singapore over the past month due to heavier-than-usual rainfall brought about by multiple weather systems.

On Aug 24, for instance, western Singapore saw more than an entire month's worth of rainfall within three to four hours, Ms Fu said.

"Given climate change, we must prepare for more extreme weather scenarios as we are likely to see more flash floods from intense rain," she said.

She added that PUB has invested almost $2 billion in drainage works in the past decade, and reduced Singapore's flood-prone areas from 3,200ha in the 1970s to 28ha today. Another $1.4 billion will be invested over the next five years in drainage improvement works.

But Ms Fu said it would not be practical to expand all 8,000-plus km of drains and flood protection infrastructure here to accommodate every extreme rainfall event, as this would require massive land take and much higher costs.

  • $2b

    How much PUB has invested in drainage works in the past decade. Singapore's flood-prone areas have been reduced from 3,200ha in the 1970s to 28ha today.

    $1.4b

    How much will be invested over the next five years in drainage improvement works.

She said building owners must take action and ensure that flood prevention measures in their developments remain effective.

Contractors must also implement proper flood prevention measures at their work sites. Citing the flood at the junction of Tampines Avenue 10 and Pasir Ris Drive 12 on Aug 20, Ms Fu said PUB's investigations showed that the contractor carrying out road-widening works in Tampines Avenue 10 had altered the public drainage system.

This was done without approval.

PUB said over the weekend that it will be taking action against construction company Samwoh under the Sewerage and Drainage Act for unauthorised drainage works.

Ms Fu told MPs: "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."

A version of this article appeared in the print edition of The Straits Times on September 15, 2021, with the headline 'More accurate rainfall forecasts by early next year with system upgrade'. Subscribe