How real time data is keeping Singapore’s floods at bay

By Jaz Low

Interview with Lee Cai Jie, Chief Engineer of Drainage Operations, Catchment and Waterways Department, PUB.

The Epic of Gilgamesh tells the story of a Sumerian king who built a giant vessel to save his family and all animal species from a world-engulfing flood. But constructing a ship of tremendous scale is far from the be-all and end-all of flood mitigation today.

Singapore’s national water agency, PUB, shares how it is putting safeguards in place for flood prevention. It has developed an intelligent monitoring system, dispatched response vehicles, and erected automatic barriers to deal with flash floods.

Lee Cai Jie, Chief Engineer of Drainage Operations under PUB’s Catchment and Waterways Department, highlights how the agency is boosting its flood response capabilities.

Caught in 4K 

As a tropical city, Singapore is prone to intense storms and heavy rainfall. Climate change has only exacerbated extreme weather and given rise to more frequent flash floods around the island-state.

PUB is using real-time monitoring of reservoirs and drains to capture flood-related data across the island. It integrates data from various sources such as rain gauges, water level sensors, CCTV cameras, and rainfall forecasts.

This dashboard allows command centre officers to easily keep track of flood-prone areas under live conditions. Officers can also refer to the data to quickly allocate manpower and station response vehicles during flooding incidents.

Officers at the command centre monitoring reservoirs and drains.

Flash floods may cause inconvenience to road users, disrupt businesses, and cause damage to properties. It’s crucial that response teams reach flooding sites as quickly as possible so they can set up portable flood barriers, close roads, direct traffic, and assist stranded pedestrians.

PUB employee setting up a portable flood barrier.

PUB is investing in radar technology to make rainfall predictions more accurate. It has six radars that can monitor rainfall within a 30 km radius in the Northern, Eastern, and Western parts of Singapore. These feed data to a model that can produce 30-minute forecasts ahead of rainfall by predicting the formation of rain clouds.

Innovations for flood response 

PUB has also rolled out a fleet of 13 new flood response vehicles to respond to flash floods quickly.
The vehicles come equipped with a GPS tracker to monitor real-time location and a surveillance camera to stream flood conditions on the road.

This allows PUB to remotely coordinate vehicle deployment from the command centre and readily direct response teams to locations where heavy rain is expected.

Flood response vehicle.

Surveillance camera on a flood response vehicle.

Building owners can also consider installing automatic flood barriers which buoy themselves up to block approaching floodwaters. When water levels subside, the flood barriers lower back underground without the need for any human or mechanical input.

PUB trialed the automatic flood barriers at the entrance of one condominium in July 2021 and found it to be a “viable and cost-efficient solution” for flood protection, Lee says. “We would definitely encourage building owners to consider them as a defense measure,” he adds.

A raised automatic flood barrier.

PUB has developed an extensive network of drains and canals over the years to quickly capture stormwater during heavy rain. “However, it is not always practical or feasible to widen and deepen our drains and canals to accommodate every extreme rainfall event,” Lee shares.

This would require a lot of land and much higher costs, which is why PUB invests in the automatic flood barriers “to keep the public out of harm’s way during flash floods,” he adds.

Their efforts have bore fruit. The size of flood-prone areas in Singapore has substantially reduced from 3,200 hectares in the 1970s to 28 hectares today.

Fail to prepare, prepare to fail 

PUB is also working on an early warning system to prepare citizens for flooding incidents. “By providing early warning to members of the public, they can avoid potential flood locations and set up flood barriers if necessary,” Lee highlights.

There are multiple channels – SMS, PUB’s Facebook Page, and an app for environment-related information –  that members of the public can subscribe to receive weather updates and flood alerts.

The newly launched Telegram channel is an additional avenue for the public to receive timely push notifications on heavy rain, potential flood risk locations and flash floods areas on the go.

“Within the first five days of its launch, the channel garnered more than 10,000 subscribers,” Lee says.

Screenshot of PUB’s Telegram channel.

PUB will continue to explore and invest in new flood management capabilities and strengthen public preparedness for floods. Ancient kings built arks to protect themselves during floods, but today data and technology are keeping citizens safe.

Pictures courtesy of Singapore’s national water agency, PUB.