Major floods in Singapore

Floods are a common occurrence in Singapore usually caused by a combination of heavy rainfall, high tides and drainage problems, especially in low-lying areas. Most floods in Singapore are flash floods that subside within a few hours. Although most floods cause only minor inconveniences, Singapore has also experienced several major floods that have resulted in widespread devastation, as well as destruction to life and property. 

Causes
Singapore receives abundant rainfall due to its tropical climate. On average, Singapore receives about 100 to 300 mm of rain each month, with November and December receiving the heaviest rainfall.The annual average rainfall is about 2,340 mm.The northeast monsoon season (December to early March), which affects Singapore, coincides with the country’s wettest months.The monsoon surges, which generally occur in December, often bring about heavy torrential downpours, which in turn cause floods.4 While the floods have not been serious in most instances, flood waters have been known to rise to chest level especially during heavy downpours.5 At times, floods may be exacerbated by incoming high tides6 as in the cases of the floods in March 1935, January 1955, September 1998, December 2000 and November 2004.7 


Storms can also occur during the non-monsoon season. These storms sometimes cause flash floods – localised floods that happen and subside very quickly.8 Traffic disruption is often the consequence of such floods as the roads are rendered impassable by flood waters.9

Major floods 
While flash floods are frequent occurrences that cause minor inconveniences, Singapore has also experienced its share of major floods that have resulted in the loss of lives and damage to properties. 


1950s 
1954 was a year of several serious floods. On 27 February, an estimated 3 inches (76 mm) of rain fell in Singapore, flooding many areas such as Rochore, Thomson Road, Balestier Road, Orchard Road and Farrer Park. Flood waters, which were between 2 and 4 feet deep (0.6 and 1.2 m) in some areas, affected hundreds of homes and caused many cars to be stranded on the roads.10 


Four months later on 17 June, flooding occurred again after a violent five-hour storm. Planes were diverted to Changi after the runway at Kallang Airport was flooded. Orchard Road was flooded once again, this time with 18 inches (458 mm) of water.11 

Between October and December that year, exceptionally heavy rainfall led to serious flooding in several areas, including Bedok, Potong Pasir, Braddell Road, Lorong Tai Seng and Geylang Serai.12 Parts of River Valley Road and the town area were also flooded, including Robinson Road, Cecil Street and Anson Road.13 More than 10,000 people were affected and nearly 5,000 rendered homeless.14 The October rain and floods affected businesses and delayed flights leaving Kallang Airport.15 During the December storm and floods, railway services to and from Malaya were suspended and flights to Singapore diverted.16 Following the December floods, a flood relief fund was set up to collect aid – cash, food, clothes and books – for the flood victims.17

1960s 
The 1969 floods on 10 December, Hari Raya Puasa, wreaked havoc throughout the island and were considered Singapore’s worst floods in 35 years. That day, heavy rain caused flooding in many parts of Singapore, with flood waters reaching waist high in some areas. Helicopters were used to evacuate people trapped in trees and on the roofs of their homes. Road and rail links with Malaysia were also cut off. Flights were delayed and telephone and electricity networks were disrupted.18


The floods claimed the lives of five people.  A woman and her son were killed when their house was crushed by landslides caused by the floods, while another son succumbed to his injuries two days later. The other two casualties were a man who was crushed by a falling tree and an elderly woman who drowned.19 Many farmers’ livestock were also swept away by the swirling waters.  About 11 relief centres were set up around Singapore to provide victims with food, drinks and temporary respite from the floods.20

1970s 
Two major floods were recorded in 1978. The first flood occurred on 10 and 11 November after thunderstorms with wind speeds of up to 23 knots were recorded. As a result, trees fell, houses flooded and two people were killed. About 75 mm of rainwater was recorded at the Paya Lebar meteorological station. The resulting floods also caused traffic jams and disrupted bus services.21 

A few weeks later, on 2 and 3 December, premature torrential monsoon rains caused severe floods. About 512 mm of rain fell over a 24 hour period, wreaking “utter chaos throughout Singapore”.22 The amount of rainfall during that period was described as “exceptional” as it accounted for almost a quarter of Singapore’s annual average rainfall.23 

More than 1,000 people had to be evacuated from their flooded homes.24 Farmers reported damage to property and losses of livestock and poultry.25 The electricity supply and telephone service in many areas were disrupted as a result of the rain and floods.26 There were also reported incidents of landslides, with some occurring in housing estates.27 The Straits Times reported seven deaths from the floods; the youngest was a 10-year-old primary school boy who had fallen into a flooded drain.28 The Chinese newspaper, Nanyang Siang Pau, reported at least eight people dead or missing.29 

1980s 
Several major floods occurred in 1980, 1984 and 1985. In January 1980, parts of Singapore were submerged under 1.3 m of water after two days of continuous rain. On 6 May the same year, thousands of workers and schoolchildren were affected when flood waters began to rise in many areas in the morning. Orchard Road was the most badly hit when the water level rose to 60 cm.30


In 1984, torrential rains in March, May and September caused flooding in many parts of Singapore, resulting in massive traffic jams and affecting many people as they left for work and school. The National University of Singapore (NUS) examination on 3 March was delayed by an hour to give students sufficient time to get to campus.31 There were reportedly 10 floods between 2 February and 27 May 1984.32 

Heavy downpours in the first half of 1985 caused flooding and traffic jams in many areas. Heavy rain and strong winds resulted in 13 trees being uprooted in several parts of Singapore on 13 April.33

Floods were generally under control in the late 1980s and 1990s when various flood control measures were put in place. These include the construction of diversion canals in flood prone areas and increasing drainage in new housing estates.34

2000s 
However, floods made the news again when the Bukit Timah Canal overflowed on 19 November 2009 following a heavy downpour that dumped about 110 mm of rain onto the area.35 Floodwaters reached knee level and caused major traffic congestion.36 


In 2010 and 2011, flash floods in Orchard Road caused much damage to property. On 16 June 2010, morning rainstorms resulted in flash floods in Orchard Road. Rainwater flowed into the basements of several buildings, including Lucky Plaza, Liat Towers, Tong Building and Delfi Orchard. The affected shops such as fast food restaurants, food courts and cafes reported heavy losses of infrastructure and equipment.37 The National Environment Agency (NEA) reported that more than 100 mm of rain fell within a two-hour period of “intense heavy rain”. The Public Utilities Board (PUB), however, attributed the cause of the floods to a blocked culvert – a drain that diverts water.38 

On 23 December 2011, torrential rain again led to severe flooding in Orchard Road. 152.8 mm of rain fell over Orchard Road between 2.20 pm and 5.20 pm that day.39 Cars were submerged in wheel-high waters and floodwaters accumulated in some shops, such as a Starbucks outlet in Liat Towers. 40 

On 5 September 2013, widespread floods occurred in the western parts of Singapore following a morning thunderstorm. The resulting floods left many motorists stranded and caused massive traffic jams on the Ayer Rajah Expressway. Parts of the Expressway had to be closed to traffic.41 

Alleviation of flooding
In 1951, a joint committee was formed under the Public Works Department (PWD) to improve the drainage system and alleviate flooding in Singapore. This marked the first coordinated effort to combat the problem under a single department, ensuring a more focused and effective approach to reducing Singapore’s flood risk. Flood alleviation projects were implemented in several residential areas, including Queenstown, Geylang, Bedok, Potong Pasir, Whampoa, Jurong, Tampines and Seletar.42 These projects usually involved the widening and deepening of the drainage network, the raising of roads in low-lying areas, as well as the construction of drains and tidal gates at rivers and reservoirs.43 


However, flooding incidents intensified as the rapid development of new housing and industrial estates led to increased surface flows to the drainage waterways. To guide the enhancement of the drainage network for better flood prevention and alleviation, the Ministry of the Environment (ENV) drew up a drainage master plan in the mid-1970s, in consultation with the Urban Redevelopment Authority (URA), Jurong Town Corporation (JTC), Housing and Development Board (HDB) and other development agencies.44

Since 1973, Singapore has invested more than $2 billion in its drainage infrastructure.45 This has helped to reduce the size of flood-prone areas in the country from 3,200 ha in the 1970s to 30.5 ha in 2016.46 One of the latest additions to the flood alleviation programme is Marina Barrage, which dams Marina Reservoir. The barrage, which was opened on 31 October 2008, features seven pumps with the capacity to pump up to 40 cu m per second. During storms, these pumps flush out excess water to the sea.47

In addition to enhancing the capacity of the drainage infrastructure, the PUB has sought to slow down surface runoff flowing into the drainage system, such as by installing detention tanks, retention ponds, green roofs or rain gardens. Since 2014, PUB has also required developers to implement such features in new developments and redevelopments that have a land size of 0.2 ha or more. These measures reduce the volume of water flowing into the drains and canals during heavy rainfall, thus lowering the risk of floods.48



Author
 

Jaime Koh 



References 
1. Micheline Fong, The Weather and Climate of Singapore (Singapore: Meteorological Service Singapore, 2012), 22, 24. (Call no. RSING 551.695957 FON)
2. “Code of Practice on Surface Water Drainage,” Public Utilities Board, Singapore, 1, 2018.
3. Fong, Weather and Climate of Singapore, 24, 70–72.
4. Fong, Weather and Climate of Singapore, 24, 74–76.
5. “Floods in Singapore,” Malayan Saturday Post, 3 December 1932, 3; “Cars Drive Through S’pore Flood,” Singapore Free Press, 3 September 1946, 1; “Floods in S’pore,” Straits Times, 12 November 1949, 7; “Floods Again, But No Chaos,” Straits Times, 2 December 1976, 9; “Flood Chaos: Thousands Marooned,” Straits Times, 3 December 1978, 1. (From NewspaperSG)
6. “Floods in Singapore,” Straits Times, 10 March 1935, 1; “Untitled,” Straits Times, 25 November 1949, 1; “Floods in Colony,” Straits Times, 20 January 1957, 4. (From NewspaperSG)
7. “High Tide Strikes,” Singapore Free Press, 12 January 1955, 1; “Floods in City Again Today,” Singapore Free Press, 12 January 1955, 1 (From NewspaperSG); “Floods in Singapore”; Dominic Nathan, “High Tide Causes Flood,” Straits Times, 10 September 1998, 25; Lee Seng Kong and Wong Teo Suan, “Freak Floods Aggravated By High Winds,” Straits Times, 5 January 2000, 43; “Rainy Days to Come,” New Paper, 5 November 2004, 5. (From NewspaperSG)
8. “Flash Floods,” Ministry of the Environment and Water Resources, 3 May 2018.
9. “Flash Floods Cause Big Traffic Jams,” Straits Times, 4 May 1973, 8; “Traffic Jams All over after Rain,” Straits Times, 5 August 1973, 15. (From NewspaperSG)
10. “Floods Ruin Homes,” Straits Times, 28 February 1954, 1. (From NewspaperSG)
11. “Planes Flew Detours in Floods,” Straits Times, 18 June 1954, 7. (From NewspaperSG)
12. Hsu Yun-ts'iao, The Sesquicentennial Chronology of Singapore, 1819–1969 (n.p., 1969), 66. (Call no. RDLKL 959.57 HSU)
13. “Downpours Flood 100-Yard Stretch of Road,” Straits Times, 1 October 1954, 5; “S’pore Flooded Again,” Singapore Free Press, 9 December 1954, 1. (From NewspaperSG)
14. Hsu, Sesquicentennial Chronology of Singapore, 66; “5,000 Homeless in Floods,” Straits Times, 10 December 1954, 1. (From NewspaperSG)
15. “Heavy Rain Hits S’pore – Then Floods,” Singapore Free Press, 23 October 1954, 1; “Flood Chaos in Singapore,” Straits Times, 24 October 1954, 1. (From NewspaperSG)
16. “Monsoon Storm Sweeps Direct into Singapore,” Straits Times, 10 December 1954, 6; “S’pore-KL Train Services Suspended,” Straits Times, 11 December 1954, 1. (From NewspaperSG)
17. “Floods: S’pore SOS for Aid,” Singapore Free Press, 13 December 1954, 1; “Floods: The Big Need,” Straits Times, 13 December 1954, 1; “Fund Opened to aid Victims of the Floods,” Straits Times, 12 December 1954,  1. (From NewspaperSG)
18. “Worst Floods in 35 Years Caused Three Deaths and Devastation Throughout S’pore,” Straits Times, 12 December 1969, 5. (From NewspaperSG)
19. Yeo Kim Seng, “13 Died during Three Major Floods in the Last 18 Years,” Straits Times, 19 January 1987, 17. (From NewspaperSG)
20. “Worst Floods in 35 Years.” 
21. “Two Killed as Storms Leave a Trail of Havoc,” Straits Times, 12 November 1978, 7. (From NewspaperSG)
22. “Early Warning,” Straits Times, 5 December 1978, 16; “Flood Chaos: Thousands Marooned,” Straits Times, 3 December 1978, 1. (From NewspaperSG)
23. Parliament of Singapore, Flooding (Prevention of), vol. 38 of Parliamentary Debates: Official Report, 10 January 1979, col. 68. (Call no. RCLOS 328.5957 SIN)
24. Yeo, “13 Died during Three Major Floods”; “Flood Chaos.”
25. N. G. Knutty, et al., “Totting Up Flood Losses,” Straits Times, 5 December 1978, 1. (From NewspaperSG0
26. “Work on to Bring Life Back to Normal,” Straits Times, 4 December 1978, 6. (From NewspaperSG)
27. “Sǐwáng shīzōng zhě bùxià bā rén, tǔ bēng dì xiàn zuìshǎo yǒu shí chù,” 死亡失踪者不下八人,土崩地陷最少有十处 [At least 8 dead or missing, landslides in at least 10 places], Nanyang Siang Pau 南洋商报, 4 December 1978, 1; “Landslide Shock for Residents of Blk 111,” Straits Times, 4 December 1978, 7. (From NewspaperSG)
28. “Flood Death Toll Raises to Seven,” Straits Times, 6 December 1978, 1. (From NewspaperSG)
29. “Sǐwáng shīzōng zhě bùxià bā rén.”
30. Yeo, “13 Died during Three Major Floods”; K. S. Sidhu and Gerald Pereira, “…But Waters Subside as the Tide Recedes,” Straits Times, 21 January 1980, 19; “All Awash after Sweeping Storm,” Straits Times, 7 May 1980, 10; “Two Huts Crashed as Storm Hits S’pore,” Straits Times, 11 August 1980, 32. (From NewspaperSG)
31. K. K. Fong, et al., “Water, Water Everywhere,” Singapore Monitor, 4 March 1984, 2; “Oh! What a Day of Chaos and Distress It Was,” Singapore Monitor, 4 March 1984, 3; “Rain Causes Floods and Jams Again,” Singapore Monitor, 25 May 1984, 1; K. K. Fong, “Flash Floods in Several Areas after Pre-Dawn Rain,” Singapore Monitor, 27 September 1984, 2. (From NewspaperSG)
32. Yeo, “13 Died during Three Major Floods.”
33. “Floods cause Big Road Jams,” Singapore Monitor, 13 February 1985, 7; “Rain Brings Floods and Uproot Trees,” Straits Times, 14 April 1985, 11; “It was Brollies, Brollies Everywhere...,” Singapore Monitor, 21 May 1985, 3. (From NewspaperSG)
34. Mint Kang, “A Three-Decade Transformation,” Business Times, 29 July 2014, 7. (From NewspaperSG)
35. Leong Wee Keat, “Bukit Timah Hit By Floods,” Today, 20 November 2009, 3. (From NewspaperSG)
36. Leong, “Bukit Timah Hit By Floods”; Lim Wei Chean, “There was Just Too Much Rain,” Straits Times, 20 November 2009, 8. (From NewspaperSG)
37. Annabelle Liang, “Blocked Drain Caused Orchard Road Flood,” MyPaper, 18 June 2010.
38. “Annual Weather Review 2010,” National Environment Agency, 25 April 2014, 4; Liang, “Blocked Drain Caused Orchard Road Flood.” 
39. National Environment Agency, Singapore, Annual Weather Review 2011 (Singapore: National Environment Agency, 2011)
40. “Flash Floods Hit Liat Towers and Other Parts of Orchard Road,” AsiaOne, 23 December 2011; Grace Chua and Feng Zengkun, “‘Pool’ at Liat Towers again after Heavy Rain,” Straits Times, 24 December 2011, 1. (From NewspaperSG)
41. Xue Jianyue, “Floods Hit Western Singapore,” Today, 6 September 2013, 1. (From NewspaperSG)
42. Tan Yong Soon, Lee Tung Jean and Karen Tan, Clean, Green and Blue: Singapore’s Journey Towards Environmental and Water Sustainability (Singapore: ISEAS Publishing, 2009. (Call no. RSING 363.70095957 TAN)
43. “$12 Mil Flood Scheme,” Straits Times, 26 October 1954, 5; “Bedok and After,” Straits Times, 27 October 1954, 6; “Plans for Reservoir No. 4 under Study,” Straits Times, 30 December 1969, 5; Amresh Gunasingham, “Wet Spell Could Trigger Flash Floods,” Straits Times, 17 November 2009, 23; Judith Tan, “PUB working to Alleviate Upper Paya Lebar Floods,” Straits Times, 7 April 2009, 23; “The Next Step – Tidal Gates for Geylang,” Singapore Free Press, 23 January 1957, 3. (From NewspaperSG)
44. Tan, Lee and Tan, Clean, Green and Blue, 209; N. S. Tan, “Interview with Centre for Liveable Cities,” (Unpublished transcript) (Singapore: Centre for Liveable Cities, Ministry of National Development, 2016)
45. Jessica Cheam, Forging a Greener Tomorrow: Singapore's Environmental Journey from Slum to Eco-City (Singapore: Straits Times Press, 2012), 35. (Call no. RSING 363.70095957 CHE)
46. PUB, “Drainage: History,” 7 September 2016. (From NLB’s Web Archive)
47. “Water Control,” Business Times, 30 August 2007, 13; Liaw Wy-Cin, “First City Reservoir Opens,” Straits Times, 1 November 2008, 3; Lee Poh Onn, “Marina Reservoir: Not Just an Engineering Feat,” Straits Times, 11 June 2009, 26. (From NewspaperSG)
48. Public Utilities Board, Annual Report 2012/2013 (Singapore: Public Utilities Board, 2013), 23.



Further resource
Khoo Teng Chye and Valerie Chew, The Active, Beautiful, Clean Waters Programme: Water as an Environmental Asset (Singapore: Centre for Liveable Cities, 2017). (Call no. RSING 333.7845095957 ACT)



The information in this article is valid as at January 2019 and correct as far as we are able to ascertain from our sources. It is not intended to be an exhaustive or complete history of the subject. Please contact the Library for further reading materials on the topic. 

Subject
Floods--Singapore
Events
Natural disasters--Singapore
Accidents
Singapore Flood of 1978