Stamford Detention Tank

The Stamford Detention Tank and Stamford Diversion Canal, or SDT and SDC in short, are key components of PUB’s prudent planning, design to lower the risks and better protect Orchard Road against floods.

1. Stamford Detention Tank (SDT), has a total size of 0.5ha, and extends 28 m below the ground. Sited underneath the coach park of Botanic Garden’s Tyersall Learning Forest and National Orchid Nursery. When there is a heavy downpour, excess storm water from the drains along Holland Road will flow into the SDT, which is big enough to hold 38,000 cubic metres of storm water temporarily – the equivalent of 15 Olympic-size swimming pools. After the storm subsides, the stored water will then be pumped back into the drains that flow to the Stamford Diversion Canal (SDC).

2. The 2-kilometre-long SDC complements the SDT by diverting part of the storm water from the Stamford Catchment towards the Singapore River when it has spare capacity to cope with a surge in the storm water. With this alternative pathway to Marina Reservoir, the existing Stamford Canal is left to serve a smaller catchment, thus protecting the area against flooding during intense storms.

3. Both SDT and SDC are complex drainage infrastructural projects and engineers faced several challenges during the construction phase. For instance, the area is densely built-up with difficult soil geology such as hard rocks. Tunnelling near the surface of such areas and the use of explosives to blast the hard rocks risk sudden soil settlement that may affect the structural integrity of nearby buildings. Our contractors partnered local firms to deploy innovative engineering solutions to overcome these challenges.

4. SDT and SDC are fine examples of the holistic “Source-Pathway-Receptor” approach adopted by PUB for storm water management. Coupled with “receptor” measures implemented by building owners such as flood barriers at developments, the completion of these two projects will significantly enhance the flood protection of the Orchard Road areas.