SMRT carries out exercise at one-north MRT station to counter flooding in stations

SINGAPORE – It took an SMRT team of six a matter of minutes to install three columns of stackable flood barriers at one-north MRT station on the evening of Dec 12.

This was done not because the station on the Circle Line was at risk of being engulfed by flood waters. It was part of the rail operator’s yearly flood preparedness exercise to get its staff ready in the event of a station flooding.

The hour-long exercise simulated a flooding event at the station near Buona Vista, based on a scenario of heavy, thundery rain with strong winds approaching from the north-east of Singapore.

As part of the exercise and SMRT’s regular flood monitoring efforts, the rail operator tapped national water agency PUB’s high-water-level alert system to monitor the threat of flooding.

When data simulated for the exercise showed that the waters in the Sungei Pandan Kechil waterway – the canal closest to the station – had risen above 75 per cent of the waterway’s capacity, SMRT’s operations control centre placed its flood response team on alert.

When the simulated data showed the waters had risen above 90 per cent of the waterway’s capacity, the flood response team was dispatched to one-north station. In a real-life situation, 20 people will be activated from across the island, and they must arrive within 45 minutes.

In the exercise, once the water level in the surrounding canal reached full capacity, the flood response team started moving stackable flood barriers to the entrances of the station that were at risk of water seeping through. These flood barriers, installed 1.3m above ground level, help block flood waters from entering the station.

In an actual flooding situation, station staff on duty will continuously monitor the station entrances for signs of flooding.

When the exercise scenario simulated waters rising above ground-level drains and submerging footpaths around the station, the flood response team installed the flood barriers, while still leaving a gap for passengers to enter and exit.

The Singapore Civil Defence Force would be notified at this point, in the event of a real flood. Passengers would also be alerted through announcements in the stations and on SMRT’s social media accounts, said the rail operator.

The flood response team would close the gap and seal the entrance once the water level rises past the midpoint of the staircases leading to the station. The team would direct passengers to other station entrances.

The flood barriers, which are in four pieces stacked one on top of the other, comprise individual metal panels and connecting columns. They are secured with locks, and airtightness tests are done to ensure no water seeps through. 

Stackable barriers are among three kinds of flood barriers SMRT has placed in 16 out of the 30 Circle Line stations.

The other types of flood barriers are full-height sliding door barriers and swing door barriers. These barriers require less labour to set up, but are available only in certain stations.

The types of barriers installed in a station depend on the station’s infrastructure and the Land Transport Authority’s assessment of flooding risk, said SMRT.

The barriers would be dismantled once the water level subsides and weather conditions improve. 

The Dec 12 exercise took place soon after Singapore experienced

its wettest November on record,

owing to frequent downpours that were mainly due to the north-east monsoon season.

Mr Lee Cai Jie, chief engineer of drainage operations at PUB’s catchment and waterways department, said managing the risk of flooding and increasing Singapore’s flood resilience are collaborative efforts.

“PUB works closely with SMRT and other critical-infrastructure stakeholders to ensure their flood preparedness, and to ensure that public and critical infrastructure such as MRT stations will be safe from flood waters,” he added.

SMRT said its station staff undergo regular refresher training in responding to flooding. The rail operator also works with agencies to assess and review its flood protection measures. 

SMRT Trains president Lam Sheau Kai said the regular flood preparedness exercises it conducts across all its train lines will ensure a fast and effective response, when needed, minimising any impact on rail services.

The rail operator was in 2018 fined $1.5 million over an October 2017 tunnel flooding incident between Bishan and Braddell stations that

disrupted train services

for about 231,000 passengers for more than 14 hours.