Singapore coastal landowners prepare for sea level rise

SINGAPORE – From 2028, all coastal landowners with at least 30 years remaining on their lease must have a plan to build coastal defences that can shield against a possible 2.15m rise in sea level by 2150.

Those with fewer than 30 years left should prepare their coastal stretch for a 0.7m rise in sea level – the projected increase in 2050 under a worst-case ice melt scenario, which has a low likelihood of occurring.

These requirements – for both private and public landowners – were revealed in a rulebook released on June 17 that details what they have to do to ensure a continuous line of defence to prevent coastal flooding in Singapore.

The Government, which owns 70 per cent of coastal land, will be responsible for protecting the majority of the coastline segments.

The remaining 30 per cent of private land is non-residential and comprises mostly shipyards and ports, as well as businesses in the oil and gas and manufacturing sectors. Most are located on the south-west and northern coastline, including Jurong Island and the industrial estates of Tuas, Pioneer and Senoko.

Announcing the release of the Code of Practice on Coastal Protection, Minister for Sustainability and the Environment Grace Fu said: “For landowners, engineers and contractors, it will provide greater clarity on what good coastal protection looks like – and how to deliver it well.”

The 80-page document covers the design requirements of coastal measures, how they should be inspected and maintained over the years, and also spells out instructions on how temporarily floodable areas such as beaches and parks should be managed with regular emergency drills.

The Code of Practice serves to guide waterfront landowners and leaseholders to fulfil their obligations under a new law, where occupants have to eventually build their own coastal protection measures.

Those who fail to do so in the future, or fail to ensure a continuous line of defence against rising seas, could face a fine and jail term.

Speaking at the Singapore International Water Week’s Coastal and Flood Resilience Leaders Summit, Fu said: “The Code will also be updated to keep pace with new findings on sea level rise and technologies to support coastal protection measures.”

The 2.15m scenario is based on Singapore’s sea level rise projections for 2150, in a situation with the worst-case greenhouse gas emissions.

However, this does not mean that a seawall, slope or coastal shield will be just 2.15m high, or 0.7m high for the 2050 scenario.

The exact height of a protective measure depends on its location along the coastline, and also has to consider factors such as storm surges, tides and waves, on top of sea level rise, according to the rulebook. Singapore’s mean sea level is expected to rise by up to 1.15m by 2100. Coupled with storm surges and high tides, seas could rise by up to 5m.

National water agency PUB will soon publish an online resource that allows architects and engineers to calculate the height of a protection structure for specific areas.

The coastal measures need to last 120 years, and any deterioration caused by exposure to the elements should not weaken their function and stability. Owners are also required to make annual declarations to PUB confirming that all inspection and maintenance requirements have been met.

If long-term landowners prefer not to build a large seawall in one go for a 2.15m scenario, they can build in an incremental manner, starting with 0.7m of sea level rise, the document states.

Fu added: “(The Code) caters for future climatic projections by giving landowners optionality in implementing coastal protection through either a single-step or incremental-steps approach.”

The rulebook will kick in from 2028. Occupiers of coastal land will be given about 10 years’ notice to take coastal protection measures.

Neighbouring coastal companies and agencies could also band together to propose one joint defence measure – such as an extended coastal slope – across several kilometres of land. To cater to this, PUB will allow companies to submit a joint declaration.

The documents also outline instructions for managing temporarily floodable areas and using deployable barriers at sites such as shipyards and ferry terminals that require access to the sea.

Such movable systems include sliding gates and raised barriers that must be installed and ready to activate when severe coastal events are forecast.

For areas that can be left to flood temporarily during bad weather, the landowner has to submit a flood response plan to PUB. The owner should also conduct flood drills at least once a year to gear up for emergencies.

One area that could be left to flood is Changi Beach Park. A study to identify the most suitable coastal measures for the eastern region included a raised platform – such as a bund – to be built farther inland to ensure access to the beach. 

PUB will hold more engagement sessions for landowners in the second half of 2026 to help them understand their obligations. The coastal protection law will likely apply to more than 100 coastal landowners.

David Ng, chairman of the civil and structural technical committee at the Institution of Engineers, Singapore, foresees that coastal firms would opt to build incrementally instead of investing in a full-sized seawall from the start.

“Spread out the investment because sea levels will not rise overnight. It may be too heavy a burden for a company to invest in a very high structure that is for use in the future,” he added.

What is most crucial is to ensure that neighbouring coastal shields interlock in a watertight manner, and their obligations under the law cause minimal disruptions to their business operations, said Ng.

“Even if two landowners have different solutions, they need to come together and discuss how to seal the gap between their property, so that water will not gush through.”