What floats your boat? The island state of Singapore is looking to flood simulation models, scenario planning and in-depth coastline studies to prepare for a climate-resilient world.

Hazel Khoo, Director, Coastal Protection Department, PUB discusses the work of her team one year since its inception. She shares the particular challenges that Singapore faces as a small nation and how it is taking a creative approach to address rising sea levels.

Tell us more about your role. How do you protect Singapore’s coastlines?

Hi, my name is Hazel and I am the Director of the Coastal Protection Department at PUB, Singapore’s national water agency.

Rising sea levels is a global challenge for many coastal cities and Singapore is especially vulnerable. This is because we are a low-lying country surrounded by the sea, with 30 per cent of our land five metres below sea level. Unlike other countries, Singapore does not have abundant high grounds for our population to retreat to.

In April 2020, PUB was appointed the national Coastal Protection Agency, and a Coastal Protection Department was set up within PUB to manage the flood risks from coastal threats. I currently lead the department to drive and coordinate whole-of-government efforts to develop long-term strategies to protect Singapore from the threats of rising sea levels. To achieve a holistic protection of coastal areas, PUB will also look at the effects of increase in rainfall intensity.

One of my tasks is to oversee the development of a Coastal-Inland Flood Model to better equip PUB for coastal protection planning and operations accounting for the twin impacts of rising sea levels and increased rainfall intensity. This model will support flood risk assessments and scenario analyses for adaptation planning. Site-specific studies, which would be conducted progressively, will formulate tailor-made coastal protection solutions for our coastlines, starting with City-East Coast in 2021. Studies for Jurong Island and the North-West Coast (e.g. Sungei Kadut, Lim Chu Kang) will commence in 2022.

What has been the most exciting thing that you worked on in the past year?

While coastal protection is a new function to PUB, earlier work from the Coastal Adaptation Study forms the foundation of our future efforts. Due to its multi-faceted nature, we have put together a team with multi-disciplinary knowledge and experiences and are still expanding it.

To accelerate our learning, we formed a Coastal Protection Expert Panel, comprising both local and international experts in the relevant fields to share international best practices and provide expert advice.

We commenced the development of the Coastal-Inland Flood Model, which will be the first in Singapore. We also embarked on the site-specific study for City-East Coast to better appreciate coastal conditions and site characteristics, guiding our formulation of adaptation measures.

In addition, we acknowledge that coastal protection offers opportunities to reshape our coastal areas. Hence, we have brought key agency stakeholders on board with us on this journey to develop long-term strategies for coastal development.

These are first steps for coastal protection work, and one giant leap in our government’s commitment to protect Singapore.

What do the coastal protection studies aim to find out?

The site-specific studies aim to understand site characteristics, identify constraints and seek opportunities to develop measures that not only protect the coastal areas from sea water inundation but also enhance the living and natural environment. The measures will complement the long-term land use of the area and incorporate elements of multi-functionality and design with nature. We expect these solutions to be different and area-specific, in view of the diversity of the coastal areas.

Coastal protection is a long-term and complex endeavour. It is important that we start planning now as these measures take time to be implemented. We will consult widely along the way – with community, experts, businesses, and other stakeholders – so that we can, together, protect Singapore’s coastlines against the rising seas while remaking them into liveable, adaptable and sustainable spaces.

 What are the unique features of Singapore’s coastlines? What makes the Jurong and East Coast coastlines more vulnerable?

Our coastal areas are highly urbanised and densely populated, making us especially vulnerable to threats from sea level rise. Land use across the 200km of coastlines is also highly varied. For example for the City-East Coast segment alone, the coasts are lined with industries, residences, recreational parks, and the financial district.

Presently, about 70 per cent of Singapore’s coastline is protected by hard structures such as concrete seawalls and stone revetments, as well as infrastructure like dams and barrage (Marina Barrage). The rest of the coastline comprises natural areas such as sandy beaches (Changi Beach Park, East Coast Park), rocky shorelines (Labrador Nature Reserve) and mangroves like Sungei Buloh Wetland Reserve and Berlayer Creek.

The study of City-East Coast had commenced first – it was prioritised based on factors such as the potential impact of a flood event, criticality of assets like airports, economic and industrial districts, and opportunities to dovetail with upcoming developments. It will be followed by Jurong Island and the Northwest Coast.

How will these different features affect the techniques needed to protect them?

Despite Singapore’s small size, our coastline is highly varied and there is no one-size-fits-all strategy when it comes to developing coastal protection measures. Coastal protection measures to be developed must complement the land use master plan of the area. We will do so and incorporate elements of multi-functionality and design with nature, where possible, to enhance the living environment. Hence, we see this as an opportunity to think creatively and reimagine ways to shape Singapore’s coastal spaces so that everyone can continue to enjoy our beautiful and protected coastline in the future.

PUB will also seek feedback and ideas from the public and relevant stakeholders to co-develop these plans and re-imagine our coastline.

What innovative solutions is PUB exploring to protect Singapore’s coastlines?

As Singapore has very limited land, we have to find innovative and creative ways to optimise our land use amid competing needs. We will design coastal protection measures that are integrated with developments and land use plans to achieve multiple purposes. Where feasible, they will be co-located with amenities and recreational spaces for the community to enhance our living environment. We will also explore the use of natural elements, including planting of mangroves, seagrasses or vegetation, to dissipate wave energy at the coasts. This provides an opportunity for us to create habitats to enhance biodiversity.

One such example we can see today is the Marina Barrage, which provides a source of water supply, flood control and a venue for leisure and lifestyle activities.

We are also exploring alternative coastal protection technology and solutions that are applicable to Singapore’s context, and will adapt these solutions to our needs. Similar to how PUB developed the four national taps to boost Singapore’s water sustainability, PUB will explore innovative methods using the latest technology to ensure Singapore’s coastline remains liveable while we strive to keep the rising sea at bay.

How can scenario planning help with flood protection?

Image of Hazel Khoo by PUB

Given uncertainties in climate and weather predictions, scenario planning helps us to strategise based on a range of possible outcomes and predictions. This will enable us to develop measures addressing conditions unique to us, considering our densely built-up environment.

As coastal and inland flooding are closely intertwined in Singapore, PUB has also commenced the development of the Coastal-Inland Flood Model in 2021 to assess flood risks holistically. This model framework will comprise a suite of fit-for-purpose tools and adopt state-of-the-art techniques to simulate the combined effects of rainfall-runoff and coastal events, thereby guiding our flood protection responses.

Through such simulations, the Model will be capable of evaluating the effectiveness of proposed coastal infrastructure under various climate scenarios to support coastal adaptation planning.

What advancements do you predict will happen in your field in the next ten years?

Technology will be a key enabler in tackling climate change challenges. Through research and development, we expect to find, test and prove effective coastal protection solutions, advance knowledge in climate science and local coastal processes, as well as enhance modelling and prediction capabilities. Some of these may involve IoT to collect and analyse real-time data, as well as artificial intelligence to support forecasting and prediction models.

A key milestone will be the completion of the Third National Climate Change Study in 2022 to provide higher-resolution climate projections for our local context. These findings provide improved understanding of the changing climate effects around Singapore based on updated global projections. This will better guide ongoing planning efforts to safeguard Singapore against the impact of sea level rise.

What countries are you learning from?

Dealing with sea-level rise is a new area in Singapore and local capabilities are still nascent. PUB has been tapping on international experts with vast experience to adapt international best practices into our coastal protection plans.

For example, we are drawing from the Dutch experience in tackling the challenges of coastal protection with storm surge barriers and their multi-layer risk management approach. We are also learning from the UK in their adaptive planning approach, adopted as part of their Thames Estuary 2100 Plan. New York City’s Lower Manhattan Climate Resilience Study, which looks at redesigning the Lower Manhattan shoreline to make it more resilient to rising sea levels, offers us insights to how multi-functionality can be integrated within coastal protection measures.

As earlier shared, PUB has also convened a Coastal Protection Expert Panel comprising renowned international experts from the Netherlands, US and UK, who have extensive track records and expertise in the implementation of coastal protection measures. The panel will share international best practices and planning considerations, and provide advice that will allow PUB to build new capabilities and aid its overall planning efforts.