WATER. DIGITAL. RESILIENCE

What should you do before and during Flash Floods in Singapore?

Written by The Waterbender (yours truly) and Hui Lim Tan, a civil engineer with seven years experience in stormwater management

24 NOV 2021

3 MINS READ

ISMAIL WEILIANG

The Climatebender

HUI LIM TAN

Co-author

Civil Engineer

Views are entirely ours

and not connected to any company

More intense and frequent rainfall with climate change

Singapore is expected to experience increasing intensity and frequency of heavy downpours with climate change. With a tropical climate, Singapore experiences intense localised rainfall that has high spatial and temporal variability. Singapore’s annual average rainfall is about 2,340 mm and receives about 100 - 300 mm of rain on average each month, with November and December receiving the heaviest rainfall. The northeast monsoon season (December to early March), which affects Singapore, coincides with the country’s wettest months. The monsoon surges, which generally occur in December, often bring about heavy torrential downpours that may lead to flashy floods.

Flash floods

Most of the floods have been minor and traffic disruption is often the consequence of such floods. Flood waters have been known to rise to chest level especially during heavy downpours. At times, floods may be exacerbated by incoming high tides as in the cases of the floods in March 1935, January 1955, September 1998, December 2000 and November 2004. Singapore has also experienced several major floods that have resulted in widespread devastation, as well as destruction to life and property.

What should I do before flash floods?

To prepare better for flash floods, you can do the following:

1 For flood alerts:

2 Know your flood-prone areas: PUB Flood Management

3 Check whether insurance coverage (personal / vehicles / buildings) includes flood damage

What should I do during flash floods?

  1. Do not walk into flooded areas or moving waters. 15cm of moving water can make you fall. If you see a flooded area ahead, turn back and move immediately to higher ground as floodwater may rise suddenly. Stay there until the flood subsides.
  2. If you have to walk in water, walk where the water is not moving. Use a stick to check the firmness of the ground in front of you.
  3. Do not remove footwear as debris might cut oneself. Flood waters may also be polluted leading to health issues.  
  1. Generally, do not drive through a flash flood. If necessary, it is relatively safe to proceed if the water depth is lower than road curbs. However, if the curbs are not visible, you may end up driving into a drain, canal or over a ledge. Just 30 cm of water may stall your car and 60cm of water can carry away your car, including SUVs.
  2. If you find yourself in the flood, drive very slowly and steadily in a low gear until your car is out of the water. Do not lift your foot or apply brakes midway. This will reduce the risk of losing steering control and prevent water from entering the exhaust pipe and damaging electronics. After clearing the flooded area, apply brakes gently for a few minutes to rid them of moisture, which may impact their performance.
  3. If your car stalls while driving through a flash flood, do not attempt to restart it as that may damage the engine. Switch on the hazard lights to alert other drivers around you and call for help. Avoid waiting for the car to get submerged as the doors may not open and you will be trapped inside. Leave the car and get to higher ground if the water level reaches the bottom edge of the car door.

Should you find yourselves trapped or in danger during flood event, please contact

  • PUB 24-hour Call Centre for Floods - 1800 284 6600 or
  • Police – 999 for assistance.


Now that you’ve braced yourselves for December, Singapore’s wettest month - Share this with your loved ones!

Authors:

Hui Lim Tan is a senior hydraulic engineer at Mott MacDonald Singapore. He has seven years of working experience in stormwater management, experienced with river modelling, dam break study, roadside drain diversion, and sediment transport. 

Ismail Weiliang is a climate resilience consultant with over half a decade of experience and specialises in flood risk advisory for Asia. His work involves advising governments and development banks on strategies to transform climate risks into resilience. He also founded “The Climatebender” a non-profit organisation that provides humanitarian relief to communities vulnerable to the climate crisis.

References:

https://www.pub.gov.sg/drainage/floodmanagement/publicadvisory

https://eresources.nlb.gov.sg/infopedia/articles/SIP_780_2004-12-30.html

https://www.straitstimes.com/singapore/ask-st-what-do-i-do-if-my-car-is-caught-in-a-flash-flood

https://www.gov.sg/article/reporting-litter-and-pollution

https://hmconsultancy.com.sg/singapore-emergency-phone-contact-number-police-ambulance-scdf-fire/

©2021 The Climatebender