Oral Reply to Parliamentary Question on Drainage Improvement at Bukit Timah Canal by Ms Grace Fu, Minister for Sustainability and the Environment

Oral Reply to Parliamentary Question on Drainage Improvement at Bukit Timah Canal by Ms Grace Fu, Minister for Sustainability and the Environment

Mr Christopher de Souza: To ask the Minister for Sustainability and the Environment whether the drainage improvement works at Bukit Timah Canal between Rifle Range Road and Jalan Kampong Chantek can be expedited.

Answer:

1 The Bukit Timah area has been historically prone to flooding due to its topography and high level of urbanisation. Over the past decade, PUB has been progressively upgrading its drainage infrastructure to mitigate flood risks in this area. Notably, PUB completed the construction of the Bukit Timah First Diversion Canal in 2019.

2 In the same year, PUB commenced drainage upgrading works to widen and deepen the Bukit Timah Canal from Rifle Range Road to Jalan Kampong Chantek. When these works are completed, Bukit Timah Canal can convey 30% more rainwater to better meet the long-term challenge of increasing rainfall intensity.

3 This is part of PUB’s continual efforts to enhance our drainage network to better mitigate inland floods. PUB has invested almost $2 billion on drainage improvement works in the last decade, and another $1.4 billion has been set aside to carry out further improvements to the drainage system from 2021 to 2025.

4 Climate change does not only bring about heavy rainfall but also drier weather conditions which may affect our water supply. Long-term planning and investment in weather-resilient water sources like NEWater and desalination are important. In the last five years, PUB has invested about $3 billion in key long-term water supply investments, including desalination plants, NEWater factories, and expansion of its used water infrastructure, and will continue with such investments.

5 Since the announcement of PUB’s upgrading plans of the Bukit Timah Canal, NParks has also confirmed plans to implement the Bukit Timah-Rochor Green Corridor in the same area. PUB has been working closely with NParks to dovetail the drainage improvement works with the Green Corridor works. This would avoid prolonged traffic diversion along Bukit Timah Road, and the inconvenience it would pose for residents, motorists, business owners and other stakeholders. However, as a result, the completion of drainage improvement works will be delayed from 2024 to 2026. We seek the patience and understanding of stakeholders during the construction works.

6 To reduce flood risks in the interim, PUB has completed several additional measures in 2022. These include raising a 450-metre stretch of Dunearn Road and deepening a 600-metre stretch of Bukit Timah Canal.

7 With more intense weather events arising from climate change, it is not feasible to expand our drains to cater for every extreme rainfall event. This would require massive land take and much higher costs. We will need to be prepared for occasional short incidences of flash floods.

8 I strongly encourage members of the public to use PUB’s communication channels to receive alerts on flood warnings, so that they can adjust their commuting plans accordingly. Managing flood risks is a collective effort.