SINGAPORE \u2013 With climate change expected to cause more erratic rainfall patterns, Singapore\u2019s approach to dealing with flash floods has been expanded, said national water agency PUB chief executive Ong Tze-Ch\u2019in. <\/p>\n
The Government will continue to invest in drainage infrastructure, but on top of that, PUB recognises the need to build up societal resilience against flash flooding, he added. <\/p>\n
\u201cWe have come to the realisation that we cannot possibly prevent every flooding event,\u201d said Mr Ong, 50, in an interview with The Straits Times on Nov 28, as the country enters the rainy north-east monsoon season \u2013 the wettest period of the year. <\/p>\n
According to Singapore\u2019s third national climate change study, the growing amount of planet-warming gases in the atmosphere is expected to bring\u00a0heavier, more intense and frequent storms. <\/p>\n
In January, monsoon surges \u2013 weather events that happen during the wet phase of the north-east monsoon \u2013 dumped large amounts of rain over the country in a short period of time.<\/p>\n
The first surge episode in early January led to a\u00a0nearly three-hour flood in Jalan Seaview in Mountbatten, caused by the confluence of high tides and prolonged rain. Most flash floods here do not last for more\u00a0than an hour. <\/p>\n
\u201cI think there is still a sense maybe that flash floods should not even happen in Singapore. But with climate change, from time to time, we can expect flash floods to happen,\u201d he said, in his first media interview since he took over the reins of the agency in late 2023. <\/p>\n
\u201cWe want to get to the stage where (a flash flood) is not such a shock as and when it happens,\u201d he added. But a lot more work is needed to build the resilience of the populace, and the first thing is to adjust the public\u2019s mindsets about flash floods here, Mr Ong noted. <\/p>\n
Mr Ong was formerly the deputy secretary of resilience at the Ministry of Sustainability and the Environment, overseeing water and food policies between 2021 and 2023. In that role, he also covered communications, partnerships and engagement at the ministry. <\/p>\n PUB recognises the need to build up residents’ resilience against flash flooding. <\/p>\n PHOTO: LIANHE ZAOBAO READER<\/p>\n<\/figcaption><\/figure>\n That experience, he said, taught him that climate action requires inputs from all of society. <\/p>\n Mr Ong noted that investment in improving Singapore\u2019s drainage system remains a key pillar of flood prevention. It was announced in February that <\/p>\n $150 million will be spent on\u00a0drainage upgrading works<\/p>\n <\/a>\u00a0in the 2025 financial year. <\/p>\n But with land constraints, there is a limit to how much more drainage can be built or expanded here, he added. <\/p>\n PUB has also undertaken the construction of more specialised flood-proofing infrastructure, Mr Ong said, citing the <\/p>\n recently completed Syed Alwi Pumping Station,<\/p>\n <\/a> which features an underground tank in the low-lying Jalan Besar area. <\/p>\n It diverts storm water from Rochor Canal into an underground tank to prevent the area\u2019s drains and canals from overflowing during a deluge. <\/p>\n Upgrading works on a 900m stretch of the Bukit Timah Canal, between Rifle Range Road and Jalan Kampong Chantek, are scheduled to be completed in 2026. <\/p>\n ST PHOTO: LIM YAOHUI<\/p>\n<\/figcaption><\/figure>\n Still, despite governmental efforts, residents, businesses and commuters in flood-prone areas also increasingly have to keep an eye on weather forecasts and flood alerts, and take steps to be out of the water\u2019s reach, Mr Ong said.<\/p>\n Currently, PUB uses a few channels to update the public on potential flash flooding, including social media platform Telegram and vehicle on-board units. <\/p>\n But Mr Ong said the national water agency will continue to invest in new ideas to provide more accurate and far-reaching early warnings to the public. <\/p>\n For example, PUB announced in mid-November as part of its annual flood awareness campaign that it is working on tapping mobile phone signals\u00a0to better predict places that may get intense rainfall. <\/p>\n This project, done with StarHub and water management solutions provider Hydroinformatics\u00a0Institute, is targeted for completion by the end of 2025, with potential for islandwide implementation.<\/p>\n When it rains, rainfall\u00a0can <\/p>\n interfere with cellular signals sent between telecommunication towers<\/p>\n <\/a>. These interferences can be tapped to estimate rainfall intensity. With how ubiquitous mobile phones are, this data can augment the information from rain gauges located islandwide, said Mr Ong. <\/p>\n PUB also said in November that it will work to integrate <\/p>\n flood alerts <\/p>\n <\/a><\/p>\n into<\/p>\n <\/a><\/p>\n Google Maps and gradually<\/p>\n <\/a><\/p>\n install 650 more water level sensors<\/p>\n <\/a> islandwide by 2028. <\/p>\n A contractor, accompanied by a PUB officer, measuring the length of a water level sensor cable after testing its accuracy next to a drain in Bukit Timah Road on Nov 25.<\/p>\n ST PHOTO: LIM YAOHUI<\/p>\n<\/figcaption><\/figure>\n PUB also started an annual flood awareness campaign in November 2024, as the country entered the rainy season. In its second run now, the focus is on educating the public about precautions they can take to avoid being caught in flood waters. <\/p>\n Asked what such action could look like, Mr Ong said: \u201cIf you\u2019re a landed (property) owner, you put out barriers. If I\u2019m a commuter, I adjust my plans. I don\u2019t walk out into the heavy rain and risk being caught in a flood. If I\u2019m a driver, I avoid the flooded area that I\u2019m notified about, or I choose not to drive right now. To me, that\u2019s resilience.\u201d<\/p>\n Protecting Singapore\u2019s coastlines from rising sea levels caused by climate change is also a relatively new area for PUB, with the agency designated in 2020 as the nation\u2019s coastal protection agency.<\/p>\n Under Mr Ong\u2019s tenure, PUB has done more public outreach on sea level rise and floods \u2013 from a series of community dialogues where participants could suggest coastal protection measures, to meetings where residents brainstormed ideas to better prepare for floods. <\/p>\n \u201cThe coast belongs to so many people. There are residents, there are companies, there are fishing enthusiasts, there are nature groups. And everybody would want some say into how they reimagine our coasts,\u201d he acknowledged. <\/p>\n For example, taking in the feedback of Changi residents and nature groups, PUB <\/p>\n proposed to construct a raised platform<\/p>\n <\/a> \u2013 such as a bund \u2013 farther inland of Changi Beach Park to ensure continued access to the beach and preserve the seagrass-rich shores. <\/p>\n Climate change could also put pressure on PUB\u2019s primary role in the country \u2013 safeguarding Singapore\u2019s water supply, Mr Ong said. <\/p>\n Of Singapore\u2019s four main sources of water, two are exposed to the elements, making them vulnerable to fluctuations in rainfall. They include imported water from Malaysia \u2013 up to 250 million gallons a day from the Johor River \u2013 and Singapore\u2019s 17 reservoirs. <\/p>\n The agreement for Singapore to import raw water from Malaysia expires in 2061. There is also limited space in the country to build new reservoirs. <\/p>\n Two other sources of water, NEWater and desalination, are more climate-resilient and are expected to provide a larger share of the local water supply in the coming decades, said Mr Ong. NEWater is produced by recycling and purifying used water and is currently mainly used for industrial processes and air-conditioning cooling purposes.<\/p>\n The country\u2019s water demand is now about 440 million gallons a day. By 2065, this could nearly double, with the non-domestic and industrial sector accounting for about 60 per cent of water consumption.<\/p>\n \u201cNEWater is essentially dependent on its input, the amount of used water that is generated by households and companies. As water demand goes up, the potential for more NEWater also goes up,\u201d explained Mr Ong. \u201cWhere we can, we will maximise this source as much as we can,\u201d he added. <\/p>\n Desalination \u2013 the process of producing drinking water from the ocean \u2013 is more expensive and energy-consuming, and its use will not be ramped up unless necessary, said Mr Ong.<\/p>\n Homes still have some way to go to reduce water use to meet the national target of 130 litres per person a day by 2030, as charted out in the Singapore Green Plan. In 2024, household water consumption crept up slightly, with each resident <\/p>\n using 142 litres of water a day<\/p>\n <\/a>, up from 141 litres in 2023.<\/p>\n PUB\u2019s chief highlighted three trends that are making it trickier to shave off the 10 to 12 litres \u2013 hotter weather, working from home and smaller household sizes. <\/p>\n \u201cThe same population split into smaller households would see greater water use. Once you have a household, there is a certain fixed water usage,\u201d he explained.<\/p>\n The trend of flexible work arrangements post-pandemic diverts water use to homes, and with rising temperatures, residents would drink more and take more showers to beat the heat. <\/p>\n Mr Ong added: \u201cThese three trends are pushing up against our target… We continue to push towards the 130-litre target as best as we can.\u201d <\/p>\n Singapore had a water price hike recently, when the price per cubic metre rose by 50 cents in total across 2024 and 2025. <\/p>\n When asked if water price is set to increase further amid climate change pressures on the resource, Mr Ong said: \u201cHave you ever seen water price come down?\u201d<\/p>\n \u201cFrom PUB\u2019s perspective, it\u2019s important for us to recover the cost of producing water. We do need to (also) collect enough revenue so that we can continue to invest in future water infrastructure that we need,\u201d he added.<\/p>\n With rising water demand, more infrastructure is needed, and that will come at additional costs. Mr Ong said: \u201cWe do take a long-term perspective to this… and that will mean water price increases from time to time.\u201d <\/p>\n<\/div>\n<\/picture><\/div>
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