Heavy rains caused flash floods in several areas in Singapore on Friday, Dec. 11 afternoon.

The Public Utilities Board sent out an alert at about 1.25pm on its Twitter account that there were flash floods at Thomson Road but traffic was passable.

As the heavy rain subsided, PUB issued a warning cancel at 2.27pm.

Almost all the flash floods were cleared by 2.50pm.

Instead of following the news all the time and wondering why is Singapore flooded, the public can get more information on PUB's website about where flood prone areas lie in Singapore because these will most likely be the places that will end up in flood-related news.

According to PUB's definition, flood prone areas are those areas which are low-lying, with a history of flooding.

Hotspots, on the other hand, are areas which are not low-lying but had experienced flash flood.

PUB's achievement over the years has been the reduction of flood prone areas in Singapore from about 3,200 hectares in the 1970s to 34 hectares today, as there are and have been numerous ongoing drainage improvement works.

Here is a list of flood prone areas:

1. Hong Kah area

2. Second Chin Bee Road

3. Commonwealth Ave / Commonwealth Drive / Queensway

4. Jalan Mat Jambol

5. Neo Pee Teck Lane/ Pasir Panjang

6. Admiralty Road West near Sembawang shipyard

7. Clover Park Estate

8. Marymount Lane / Marymount Road

9. Jalan Taman

10. Stevens Rd/Balmoral Rd

11. Farrer Park Area (including Thomson Road / Derbyshire Road) / Farrer Park Field

12. Waterloo St / Albert St / Bencoolen St / Prinsep Street

13. Jalan Besar Area

14. King George's Avenue (People's Association HQ)

15. CTE near Slip Road to Moulmein Road

16. Arab St/Rochor Canal

17. Jalan Mashor

18. Delta Road/ River Valley Road/Delta Avenue

19. Alexandra Road / Jervois Road/ Bishopsgate Road

20. Lower Delta Road / Alexandra Road

21. Leng Kee Road

22. Beach Road

23. Margaret Drive/Tanglin Road

24. Viking Road

25. South Bridge Rd/North Canal Rd/Upp Hokien St/Upp Pickering St

26. Indus Road

27. Kim Tian Road/Tiong Bahru Road

28. Zion Rd (Boys' Brigade HQ)

29. Delta Ave (APSN Delta Senior School)

30. Langsat Road Area

31. Rose Lane

32. Sennett Estate (Puay Hee Ave, Siang Kuang Ave, Wan Tho Ave, Jln Kemboja, Mulberry Ave and Jln Wangi)

33. Meyer Road / Fort Road / Arthur Road / Margate Road / Ramsgate Road

34. Jalan Seaview/Tanjong Katong Rd South

35. Jalan Gembira

36. Jalan Benaan Kapal

37. Service road off Tampines Road (near Jalan Teliti)

38. Lorong Buangkok

39. Mimosa Walk

40. Mindef’s Changi Camp off Farnborough Road

41. Bedok South Rd/Bedok South Ave 1

42. Chin Cheng Ave

43. Lorong H Telok Kurau near Siglap Canal

44. Upp East Coast Rd (junction with Parbury Avenue)

45. New Upper Changi Rd (Chye Heng Garden)

However, even though this might sound like a lot of areas, when checked out on the map, they represent a small fraction of areas (those marked out in blue):

Here is a list of hotspots in Singapore:

1. Tengah Flyover exit 35 toward KJE

2. Wan Lee Road

3. Alexandra Rd/ Pasir Panjang Rd/ Telok Blangah Rd junction

4. PIE, Anak Bukit Flyover (near exit 26A)

5. PIE, Anak Bukit Flyover (near exit 26B)

6. Dunearn Road from Wilby Road to Blackmore Drive

7. Cuscaden Rd / Tomlinson Rd junction

8. Orchard Road/ Claymore Drive Junction

9. Orchard Road/ Scotts Road Junction

10. Napier Rd/ Tanglin Rd Junction

11. Orchard/ Cuscaden Road Junction

12. Cuscaden Rd

13. Shenton Way/ Boon Tat Street/ Boon Tat Link

14. Craig Rd / Tg Pagar Rd Junction

15. Maxwell Road / Tg Pagar Road Junction

16. Tiong Bahru Rd

17. Merryn Road's slip road towards PIE

18. PIE towards Jurong before Whitley Road near 18.5km

19. Balestier Road near Prome Road

20. Mandalay Road/ Minbu Road Junction

21. Mayflower Ave /Ang Mo Kio Ave 3 Junction

22. Upper Thomson Road/ Jalan Keli

23. Kampong Ampat

24. Upper Paya Lebar Road

25. Harding Rd

26. Camp Rd / Tanglin Rd Junction

27. Sixth Ave / Bt Timah Rd junction

28. Stevens Close

29. Dunearn Road( near College Green)

30. Tampines Ave 12 near exit to TPE

31. PIE towards Airport after Bedok exit (7.5km)

32. Bedok North Ave 4

33. TPE below Punggol West Flyover

34. Jalan Tari Zapin (near Jalan Kayu)

35. Lorong Marican

36. Lorong Melayu

37. Mandai Road/ Woodlands Road Junction

38. Tanah Merah Besar Rd

39. Aviation Drive

40. Sunset Terrace/ Drive/ Way

41. Hillview Avenue/ Hillview Road

42. Lorong Ah Soo

43. Tampines Road (opp. Jalan Teliti)

44. Mount Elizabeth

45. Chai Chee Road/ Upper Changi Road junction

46. Lorong 1/ Lorong 2 Toa Payoh junction

47. Arumugam Road

48. Macpherson Road / Harvey Road Junction

49. Boon Keng Rd / Bendemeer Road

50. Yishun Ave 2/Yishun Ave 5 (Slip Road)

51. KJE (2km, towards PIE) to Woodlands Road (Slip Road)

52. Woodlands Road /Mandai Estate Junction

53. Jalan Boon Lay (near International Road)

54. Boon Lay Way/Corporation Road (Slip Road)

55. Lorong Kismis

Here are some photographs from Twitter of floods that happened today:

Heavy downpour causes flash floods around Singapore https://t.co/Y6zN5NyAU1 #sgflood pic.twitter.com/q3CLq8MwAX

— TODAY (@TODAYonline) December 11, 2015

Top photo by Wilson Tiow