At a press conference yesterday, the PUB said the heavy rains were responsible for sweeping the debris into the drain. -- ST PHOTO: AZIZ HUSSIN
IT WAS just a single drain, about the width of an SBS bus. But it was so badly blocked by debris that it triggered the flooding of Orchard Road on Wednesday.
The critical culvert, at the junction of Tanglin and Orchard roads, drains into two parallel channels flowing under Orchard Road - a drainage system called the Stamford Canal.
The first heavy downpour of the morning had carried debris and vegetation into the 2.7m by 2.7m culvert, starting a chain of events that led eventually to the flash flood.
It was choked where it drained into the side of Delfi Orchard, so water was directed only into the side along Forum the Shopping Mall.
When a second intense rainstorm the same morning added more water to the drains within a short period of time, the canal overflowed and water gushed up to the surface of Orchard Road, causing the worst floods there in 26 years.
Worst-hit was the junction of Scotts Road and Orchard Road, the lowest-lying part of the area. Near the intersection, shops at Liat Towers and the Lucky Plaza basement were flooded.