Unauthorised drainage works caused flooding at Pasir Ris-Tampines junction, PUB to take action against company

SINGAPORE: Unauthorised drainage works by building company Samwoh Corporation caused extreme flooding at the junction of Tampines Avenue 10 and Pasir Ris Drive on Aug 20, mentioned nationwide water company PUB, including that it is going to be taking enforcement action against the agency.

In a press launch on Saturday (Sep 11), PUB mentioned that it carried out a “thorough investigation” to decide the reason for flooding, which lasted almost two hours and affected a 200m part of the visitors junction.

PUB’s findings confirmed that Samwoh, which is finishing up highway widening works alongside Tampines Ave 10, had blocked off the prevailing roadside drain and diverted the stormwater movement to a brand new drain part that was nonetheless underneath building. 

The new drain part was not correctly linked again to the prevailing drain and was partially obstructed by scaffoldings. 

Samwoh had additionally failed to search PUB’s approval to proceed with the proposed drainage diversion works, mentioned the company.

“Samwoh’s unauthorised drainage works significantly impeded the discharge of stormwater into the downstream Sungei Api Api, resulting in floodwater accumulating at the traffic junction as it is the lowest point in the vicinity,” it added.

After the flood, PUB carried out web site investigations on the identical day and located unauthorised alternations to the prevailing roadside drain inside Samwoh’s worksite, famous Mr Lee Cai Jie, who's chief engineer for drainage operations at PUB’s catchment and waterways division.

"PUB then instructed Samwoh to stop work and direct all their resources to carry out urgent work to remove the obstruction in the new drain and improve the uncompleted drain section. Samwoh completed the rectification work by midnight on 20 Aug," he added.

PUB’s water stage sensors confirmed that Sungei Api Api, which discharges to the ocean, was about half full at the time of the flooding incident.

During the flood, 13 autos have been discovered partially submerged in water and several other motorists required assist to evacuate their autos, mentioned PUB.

PUB’s fast response staff officers, along with officers from the Land Transport Authority, Singapore Police Force and Singapore Civil Defence Force, diverted visitors and assisted stranded motorists and pedestrians.