Mechanics: How it flooded in Orchard Road

Causes of flooding in Orchard Road

1) Heavy storms and high rainfall

 About 100mm of rain fell in the central parts of Singapore between 8am and 11am on Wednesday. This was more than 60 per cent of the average monthly rainfall for June.This time, flooding occurred because of the pattern of rainfall: An intense amount of rain in short bursts at about 9.30am and at 10.30am.

2) A blocked culvert

A culvert is a drain that diverts water. The culvert, which is 2.7m in width and depth, diverts water from drains in Nassim Road and Cuscaden Road into two sections of Stamford Canal, which runs along Orchard Road. However, there was a blockage which caused the flood that submerged Orchard Road in knee-high water.

This was because there was a heavy storm on Wednesday, thus a lot of debris - such as leaves, branches and litter – was being swept into the culvert, causing part of it to be clogged. As a result, water could not flow into Stamford Canal's smaller section, which stretches from Delfi Orchard to Lucky Plaza and it flowed into the canal's other section stretching from Orchard Parade Hotel to Liat Towers and Wisma Atria. It was unable to handle the full load despite being larger.

The first burst of rain washed the debris into the culvert, but there was insufficient rain in the ensuing hour. Flooding occurred because of the pattern of rainfall: An intense    
amount of rain in short bursts at about 9.30am and at 10.30am.

The next burst of rain then washed more debris into the culvert, aggravating the initial blockage and clogged a third of the culvert.

Consequences of June 16th Orchard Flood

Shopping Malls along Orchard Road like Lucky Plaza and Liat Towers were affected by the flood.

It made some shopping malls and their car park basements to be submerged in water.

Rescuers had to pull out about 70 passengers from cars and buses, as flooding shut down Orchard Road, which is filled with high-end shopping malls and tourist attractions.

 But luckily there were no injuries.

Retailers affected by Flood: Starbucks (One of the worst-hit retailers in the area)

Turned the intersection outside Liat Towers into tea-coloured canals within three hours of the day’s morning downpour.

The supervisor (Ms Jessie Chan) of the popular coffee chain said that the clean-up would take at least two days. But the floodwaters knocked out power, which forced contractors to work with torches in darkness throughout the night, and staff members clearing the mess made by the mugs and flasks which fell everywhere during the flood.

But the supervisor said their priority was to take care of their staff, ensuring that no one’s job is affected.

-Wendy’s

Despite being a new fast-food outlet, its store was stripped bare after the flood to clear up the mess.

At about 10.20am, water streamed into Wendy's Liat Towers Outlet and soon rose above knee-level - within mere minutes, recalled shift supervisor Sarbiah Abu Hassan, 47. It was a unhappy ending to that day’s business, sending food, fittings and takings down the tubes.

The flood made them lose around $500,000.

But six months later, the whole scenario changed totally.

Business has been good, said Ms Goh Wee Ling, corporate communications manager for Wendy's Singapore. She would not say how many customers drop by daily but added that the extensive media coverage of the Orchard floods has given Wendy's a lifeline.

 'People got to know that Wendy's is at Liat Towers,' she said.

Ways to Prevent Floods or Minimize Damage At Least

1)Have More Green Buildings

The spaces in between buildings and their roofs are good spots to hold rain water. This means that it can prevent excess water from flowing onto the streets and flooding them but instead stay on the roof of the buildings. Shoppings centres can collect the rain water on the roof and use it for flushing toilets or to water rooftop gardens. However, green buildings are expensive to build, hence experts suggest incorporating green strategies in future building plans.

A rooftop garden which can hold excess rain water

 2)Build a more pipes or drains

As it would be too expensive to build everything to prevent a flood, we cannot deny simple and less costly solutions like building another pipe or drain, at the cost of some land space. These extra pipes and drains can channel out a lot more excess rain water away to prevent floods in areas.

3) Have pavements made out of porous concrete or detention basins.

Porous concrete can store some rain water in their pores, while detention basins can stem the flow of water in the event of sudden heavy downpours, helping to reduce the possibility or severity of a flood.

Porous concrete can help to absord some rain water

4) Stop complaining, start acting

Instead of complaining about floods, we ourselves should do our part to prevent them. We should stop littering as litter can clog up drains and hence cause floods. The PUB will install more debris traps in drains too to prevent debris and litter from being washed into drains and clogging them.

Multiple clogged drains can lead to a flood