SINGAPORE - A new underground detention tank will be built beside Syed Alwi Road by 2025 to prevent flooding in the low-lying Jalan Besar area.

Construction of the tank, due to begin in the third quarter of this year, is part of Singapore's wider efforts to adapt to climate change, which will bring about more frequent and intense rainstorms.

When completed, it will be able to hold about 9,300 cubic metres of water, or approximately the total capacity of four Olympic-sized pools.

National water agency PUB said on Monday (Jan 25) that the tank is designed to cut off the water flow from Rochor Canal into the drains along Syed Alwi Road. It will also temporarily store stormwater that falls over the catchment. During and after storms, the water will be pumped out of the tank and back into the canal.

PUB has previously made efforts to combat flooding in the area.

In 2015, the Rochor Canal, which runs along Sungei Road and Rochor Canal Road, was widened and deepened to improve its capacity.

Other measures to reduce flood risks like raising the buildings and roads in the area are not possible as a large portion of Jalan Besar has been gazetted as Conservation Areas, said a PUB spokesman.

Plans for the tank at Syed Alwi Road, the third one to be built, were first announced by former Minister for the Environment and Water Resources Masagos Zulkifli in Parliament last year.

The other two tanks are in Opera Estate near Bedok, which was completed in 2002 with a capacity of 15,000 cubic metres, and Stamford Detention Tank in Tanglin, near Orchard Road, which has been operating since 2018 with a capacity of 38,000 cubic metres.