Hoe Pei Shan and Audrey Tan The Straits Times AsiaOne 20 Nov 14;
A heavy midday downpour led to damage and disruption yesterday in Tampines Road, one of a handful of areas which saw flash floods in the afternoon.
The intense rain caused water to overflow from the Tampines Canal into residential areas, trapping parked cars, causing power outages and flooding homes.
Tampines Road was identified by PUB as a "hot spot" for flash floods, but the authority is hoping to address the problem with drainage improvements.
Physical works to widen and deepen the Tampines Canal are expected to start in the first quarter of next year. PUB is also currently upgrading the roadside drains in Jalan Teliti, and this is slated for completion in the third quarter of next year.
"When completed, these works will increase flood protection for the Tampines Road, Jalan Teliti and Hougang Avenue 1 areas," said a PUB spokesman.
Yesterday, water levels reached the windows of cars parked in the basement of Fortune Park Condominium in Tampines Road.
Residents of some houses along the road waded in ankle-deep water, with several expressing worries about coping with floods.
"Before the canal gets widened, PUB should make sure it responds more quickly when called to get pumps in, to minimise damage to property and disruption to residents," said Madam Ho Gek Leng, who chairs Fortune Park's management committee and has lived there for 18 years.
Residents could not get to work as they had to settle insurance claims or clean up homes, she said. "There have been cases of flooding in the past here, but this is the first time that it is this bad."
Other areas hit by flash floods yesterday included Lorong Gambir, MacPherson Road and Lorong Ong Lye - all of which are also set for drainage improvement works next year.
The highest rainfall recorded as at 5pm yesterday was 62.6mm in the Paya Lebar area - about a third of the record 160.8mm so far this month.
More thundery showers are expected over many areas this afternoon.
Additional reporting by Audrey Tan
Heavier year-end rainfall still within expected range: Experts
Monica Kotwani, Channel NewsAsia 19 Nov 14;
SINGAPORE: The Meteorological Service Singapore expects a "slightly more active" Northeast Monsoon this year. The rainfall for Nov and Dec is forecast to be about 20 per cent above the normal average - but experts say this is still within the expected range.
As of mid-Nov, Singapore has already experienced more than two-thirds of the month's average rainfall. The wet phase of the coming monsoon will bring short periods of moderate to heavy showers in the afternoons and evenings.
However, Assistant Professor Winston Chow of the geography department at the National University of Singapore told Channel NewsAsia on Wednesday (Nov 19) that it would be unusual if the upcoming monsoon showed extreme weather patterns.
"When we look at the long-term records - more than 30 years of data - there will be periods where there is less rainfall, periods where there is more rainfall. A 20 per cent increase still falls within what we would expect for the natural variation of rainfall for this particular month," he said.
"We would be interested in extreme weather - for instance, earlier this year in February, we only received 0.2mm of rain for the entire month. That has not been recorded before in Singapore, so that is an extreme event."
In this case, Asst Prof Chow said extreme weather translates to more intense and frequent rainfall. While it is too early to tell, he said climate change could be one of the reasons if indeed there are more frequent and intense rainstorms during this monsoon season. Another reason could be an El Nino weather pattern setting in.
But what eventually results in flash floods could also be due to a multitude of factors. National water agency PUB said flash floods occur due to intense rains especially in low lying areas, constricted drains and road depressions.
PUB said its measures to address flash floods go beyond the expansion of drains, and include the monitoring of CCTV cameras and water level sensors. In light of the monsoon season, it is also providing flash flood updates on its website - such as providing information on where the flood occurred and at what intensity. It also sends alerts through SMS and its MyWaters app, which has about 10,000 subscribers so far.
- CNA/ac
PUB ready to tackle looming threat of flash floods
AUDREY TAN Straits Times 20 Nov 14;
Singapore has the infrastructure in place to minimise disruption from flash floods during the oncoming north-east monsoon season, said PUB, the national water agency, yesterday.
However, it warned that these may not be able to "cater to the most extreme of storms".
The authority said that, as of Monday, there have been 14 flash flood days this year.
More could occur in the final two months of the year - traditionally the wettest for the Republic.
There were 36 flash flood days last year, up from 23 in 2011, and experts said causes could include increased urbanisation and climate change.
Assistant Professor Winston Chow of the National University of Singapore's geography department said: "The increasing frequency of extreme weather events, such as intense rain or droughts, is consistent with other scientists' observations on climate change."
Mr Ridzuan Ismail, PUB's director of catchment and waterways, said the growth of urban areas in Singapore has led to more rainwater in developed areas flowing into drainage canals.
However, the agency said yesterday that it has adopted a suite of measures to address flood risks.
It has completed 163 drainage projects over the past three years at locations such as Toh Tuck Road and Rochor Canal.
About 133 drainage projects are currently under way, and 23 more will be undertaken by next year.
PUB told The Straits Times that it requires drains to be open in low-lying areas at risk of flooding. In areas where there are space constraints, drains could be closed and water is let in through inlets instead.
The latter "have the advantage of doubling up as a footpath", and PUB said it ensures both types of drains are "adequately sized".
Mr Chong Kee Sen, president of The Institution of Engineers, Singapore, said: "As long as adequate drainage paths are designed to lead rainwater into the drain quickly and effectively, there is no significant difference between covered drains and drains with grille tops."
PUB encourages building owners to play a role in protecting their properties against floods.
Its Code of Practice on Surface Water Drainage, for instance, requires developers to include features that retain or slow down rainwater.
The agency lists 48 flood- prone areas and 55 flooding hot spots on its website.
Flood-prone areas are low- lying places with a history of flooding, while hot spots are areas that are not low-lying but have experienced flash floods.
The Meteorological Service Singapore (MSS) warned on Tuesday that rainfall this month and next will be about 20 per cent above the long-term average of 257mm and 288mm respectively. The first half of this month has already been wetter than usual, with 188mm of rainfall recorded so far.
The MSS also expects short, moderate to heavy thundery showers during afternoons and evenings over the next two months, as the annual north-east monsoon season takes hold. It added: "Heavy rain coinciding with high tides could lead to localised flash floods in low-lying areas."
