PUB seeks design ideas to protect north-west coastline

National water agency PUB is moving to beef up Singapore's defences against the rising tides in a way that is flexible and sensitive to the land-use needs of the area.

Instead of a one-size-fits-all approach, such as building sea walls all around the country, PUB is looking for solutions tailored to different parts of the country's coastline.

Yesterday, it started calling for proposals that could be adapted to protect a 17.1km stretch of coastline in Singapore's north-west.

For the first time, applicants have been asked to submit design proposals for how such protection measures can be incorporated.

This segment of the coast encircles the Sungei Kadut and Lim Chu Kang areas, which will house the future Sungei Kadut Eco-District, the upcoming Lim Chu Kang high-tech agri-food cluster, as well as a number of pristine nature areas such as the Sungei Buloh Wetland Reserve.

Recognising that rising sea levels pose a major threat to Singapore, the proposed coastal protection solutions should cater to a rise of up to 5m in sea levels and the rainfall projected due to climate change, said PUB in its tender documents.

Studies are ongoing to tease out the impact of global climate change on the rate of sea-level rise in Singapore under research efforts such as the National Sea Level Programme, and other site-specific studies on Jurong Island and the city-east coast stretch.

The latest call for proposals aims to supplement the information gleaned from those studies, by looking at various coastal protection measures that can be deployed to sites with different characteristics and land-use plans.

For instance, key landmarks in the north-western area that require protection include the Woodlands Checkpoint, Kranji Reservoir and Sungei Buloh Wetland Reserve, as well as several nature parks including Kranji Coastal Nature Park and the upcoming Lim Chu Kang Nature Park and Mandai Mangrove and Mudflat nature park.

Ms Hazel Khoo, director of PUB's coastal protection department, said: "In view of these site characteristics and landmarks, (there are some) key considerations for the coastal protection strategies and measures."

The 17.1km coastline comprises three main segments in all.

They are a 7km stretch that currently encircles many mangrove-rich nature areas, as well as agricultural land that will be redeveloped into a high-tech agri-food cluster; a 3.3km stretch that covers an industrial zone and also an upcoming nature park; as well as a 6.8km stretch that incorporates the Woodlands Checkpoint, and some nature zones including the Rail Corridor.

Ms Khoo said: "There is a need to place more emphasis on conceptual design to achieve a sustainable and liveable coastline."

Among the proposal documents required are a detailed outline of the applicant's design intent and approach, a list of possible measures suitable for the three different study zones, as well as artist's impressions and cross-sectional sketches envisioning the future coastline, Ms Khoo explained.

Up to four pre-qualified applicants will be shortlisted to participate in the second stage of the tender, which is scheduled to open in the fourth quarter of this year.

The study for this section of the north-west coast is expected to commence in the second quarter of next year and conclude by 2030.

With about 30 per cent of the island being less than 5m above sea level, Singapore is vulnerable to the effect of rising sea levels.

Based on the second national climate change study by the Centre for Climate Research Singapore, it was projected that by 2100, the mean sea levels for Singapore could rise by up to 1m.

Coupled with phenomena such as storms brewing offshore that generate surges in tidal heights as well as factors such as sinking land, sea levels could be even higher - up to 4m or 5m.