Coastal barriers & raised structures to be built along S'pore coastline to combat rising sea levels: PUB

National water agency PUB has completed the first coastal protection site-specific study (SSS) for the City-East Coast, which includes Greater Southern Waterfront (GSW) and Changi.

The SSS, which began in 2021, has recommended the construction of coastal barriers to protect a substantial portion of the GSW coastline, as well as a combination of solutions such as raised structures and tidal gates for Changi.

The measures for GSW and Changi, together with 'Long Island', will form a continuous line of defence to protect City-East Coast against rising sea levels.

GSW region

The GSW region will be a new major gateway and location for urban living along Singapore's southern coast.

Key developments include residential and commercial areas like HarbourFront and Keppel Bay, as well as green spaces like Berlayer Creek.

The area, along with Sentosa Island and Pulau Brani, will be transformed into a mixed-use waterfront precinct with top leisure and tourism developments.

The coastline comprises three sections:

• From Pasir Panjang Ferry Terminal to Labrador Nature Park
• From east of Labrador Nature Park to Tanjong Pagar Terminal
• From Marina South to Marina East

To combat rising sea levels, three coastal barriers and shoreline measures have been recommended.

The measures will ensure that land use is optimised and waterfront experience is preserved, while also making sure that the public will still have access to the coastline and improve connectivity.

Coastal barrier measures

A total of three coastal barriers will be built.

The first two will link eastern Sentosa to Pulau Brani and to mainland Singapore, creating opportunities for integration with future linkages proposed under the Greater Sentosa Master Plan.

The third coastal barrier will connect western Sentosa to mainland Singapore.

Further studies on technical feasibility, cost and impact on biodiversity will be conducted to determine the exact locations.

The coastal barriers will comprise a series of gates across the water channels and will remain open by default for maritime activities, as well as to allow seawater to flow through freely and minimise the impact on the environment.

During high tide and storm surge conditions, the gates will close, protecting the area against coastal flooding.

Seawall alternative considered

An alternative approach considered PUB had considered involved raising seawalls and constructing tidal gates along the entire waterfront promenade.

However, sea views would be obstructed and more waterfront land would be taken up.

With regard to the coastline regions from Pasir Panjang Ferry Terminal to Labrador Nature Park, and from Marina South to Marina East, existing measures will be upgraded.

These upgrades include the raising of existing revetments at Marina South, while Marina Barrage will be remodelled to withstand future sea level rise.

Changi region

Changi's coastline features recreational spaces such as Changi Beach Park, as well as industrial and aviation facilities such as Changi Aviation Park and Changi Airport.

The coastal protection measures recommended for Changi's coastline include a combination of bunds, revetments and tidal gates.

Setback measures

One of the possible measures would have been to raise the bunds in Changi Beach Park, which can also double up as a footpath or cycling track.

After gathering feedback via PUB's stakeholder and community engagements, the measures at the park will be positioned further inland to ensure continued access to the beach and minimise the impact to existing intertidal habitats.

Though such areas forward of PUB's coastal protection measures may see occasional, temporary flooding during extreme high tides, the design ensures continued waterfront access under normal conditions.

Tidal gates

PUB is also planning to install tidal gates at key locations where existing major canals discharge to the sea.

The gates will prevent the intrusion of seawater during high tide conditions.

Further studies will be conducted to determine the location and design of the gates, making sure that they integrate seamlessly with the landscape.

Shoreline measures

Changi South will see revetments or seawalls built on the coastline.

For areas where such structures are already in place, the structures can be raised to enhance protection against future sea level rise.

Construction expected to commence from 2030s

Over the course of the SSS, PUB worked to develop multi-functional spaces that take into account land use plans, while protecting the country from coastal flooding at the same time.

PUB also gathered feedback from their stakeholders through a series of public dialogue sessions titled "Our Coastal Conversation."

Various participants including residents, community leaders, nature groups, businesses, professionals and recreational users were also consulted on the solutions they would like to see.

Studies to develop the preliminary and detailed engineering designs of the recommended measures, which will include environmental impact assessments, will be conducted subsequently.

Construction of the measures listed above is targeted to start from the 2030s.

Top photo via PUB