Highest Daily Rainfall in 2020 and 2021, and Cost of Heavy Downpours to Properties

Mr Melvin Yong Yik Chye asked the Minister for Sustainability and the Environment (a) what was the highest daily rainfall experienced in 2020 and 2021 respectively; and (b) what were the damage to public and private properties that resulted from the heavy downpours.

Based on records from the Meteorological Service Singapore, the highest daily rainfall recorded in 2020 and 2021 was 185.2 millimetres (mm) on 29 January 2020 and 247.2 mm on 24 August 2021 respectively.

The 29 January 2020 rainfall did not result in any known flash floods.

The 24 August 2021 rainfall was also the highest daily total rainfall ever recorded for the month of August. This was almost 40% higher than the previous record set in August 1983. More than the average monthly August rainfall fell in western Singapore within three hours. The intense rain resulted in localised flash floods at two locations, namely, along Dunearn Road between Sime Darby Centre and Binjai Park with a flood depth of about 400 mm, and along Cashew Road leading to Upper Bukit Timah Road with a flood depth of about 150 mm. These localised flash floods lasted around 40 minutes at Dunearn Road and 30 minutes at Cashew Road.

Mr Melvin Yong asked about the damage to properties that resulted from the heavy downpours. PUB does not have such data.

As climate change brings about more extreme weather scenarios, we are likely to see more flash floods from intense rain. PUB will continue to strengthen our forecasting and sensing capabilities and implement cost-effective measures to minimise flood risks.

Notwithstanding, managing flood risks requires our collective efforts. I strongly encourage members of the public to make use of the communication channels that PUB offers to obtain up-to-date and accurate information on heavy rain alerts and flood warnings. These channels include PUB’s newly-launched Telegram channel, as well as the myENV Mobile App and LTA’s Expressway Monitoring Advisory System. Property owners in flood-prone areas can also take measures to protect their properties. These include adding structural measures, such as humps and flood barriers. PUB will continue to offer advice and loan equipment, such as portable flood barriers and sandbags, to property owners as needed.