PUB, the national water agency, is embarking on new drainage improvement projects at 36 locations, adding to its on-going drainage projects at 176 locations around Singapore.
These drainage improvement projects are part of a "source-pathway-receptor" strategy to improve flood protection for Singapore, said PUB on Monday.
Besides "pathway" solutions, PUB will also implement a "source" measure - the construction of the Stamford Detention Tank, which is scheduled to start by end of this year.
Sited near the junction of Tyersall Avenue and Tyersall Road, the detention tank will help to reduce the peak flow of stormwater into the public drains and better protect the Stamford Canal catchment against floods during intense storms. With a storage capacity of about 38,000 cubic metres or 15 Olympic-sized pools, the Stamford Detention Tank will be built underground. Occupying a subterranean footprint of about 0.5 hectares, the tank will be sited directly beneath a nursery and a coach bay of the upcoming Singapore Botanic Gardens' Learning Forest extension.
Once completed in 2016, the detention tank will be able to temporarily hold excess stormwater from the drains along Holland Road, which is the upstream area of the Stamford Canal catchment. After the rain subsides, the water will be pumped back into the drains for subsequent discharge into the Marina Reservoir.
Besides the detention tank, PUB will be constructing the Stamford Diversion Canal which will divert stormwater from the upstream section of the Stamford Canal catchment to the Singapore River. The work will be carried out in phases, with two tenders to be called. The first tender will be called in the fourth quarter of 2013 and the other tender will be called in the first quarter of 2014. Work on the entire diversion canal is expected to be completed by 2017.
Under the long-term drainage upgrading of Sungei Pandan Kechil, PUB will be carrying out the detailed design in 2014, followed by the widening and deepening of the canal in 2015. In the interim, PUB has enlarged the inlet and outlet points of the culvert crossing at AYE 9.6km to improve the flow of water. The agency will also be calling a tender for the construction of a tidal gate in November this year.
Other drainage upgrading works at Alexandra Canal Subsidiary Drain "F" (between Tiong Bahru Road to Havelock Road) and Siglap Canal (between ECP to the sea) will also start in the second and third quarter of 2014 respectively.
Drainage improvement projects at 176 locations are also on-going across the island. These include works at major canals or outlet drains like Bukit Timah 1st Diversion Canal, Rochor Canal, Alexandra Canal, and Sin Ming Outlet drain / Marymount Rd Culvert.
In the last two years, PUB has completed drainage improvement projects at 90 locations. Some of these completed projects include works at Geylang River from Guillemard to Dunman Road, Bukit Timah Canal from Maple Avenue to Kampong Chantek, and upgrading of roadside drains across the island such as at Meyer Rd and Sunset Drive/Way.