As the effects of climate change intensify, water scarcity is becoming an acute concern for cities around the globe, with many relying on resources imported from beyond their boundaries. Just three percent of the world’s water is fresh water, and at current consumption rates, the World Wide Fund for Nature estimates that by 2025, two-thirds of the population may face shortages. As the United Nations Climate Change Conference (COP26) seeks to reboot our response to the climate crisis, adaptation and resilience to protect communities from its inevitable impacts are high on the agenda.

The island nation of Singapore, comparable in size at 729 square kilometers to the small Gulf state of Bahrain, is well-acquainted with water stress. Lacking a hinterland, it relies on neighboring Malaysia for part of its water supply.

Singapore has therefore applied considerable foresight and effort over recent decades to build water resilience. Under its “Four National Taps” policy, its domestic supply draws on water piped from Malaysia, water collected from local catchments, a massive reuse program implemented in 2003 called NEWater, and desalinated seawater.

Now, the government of Singapore, in partnership with one of the country’s largest sustainable infrastructure companies, has taken this a step further. With Keppel Infrastructure — part of the Keppel Group — in charge of implementation and operations, it has found a way not only to create the world’s first large scale dual-mode water desalination plant — which switches between desalinating seawater and treating reservoir water — but also to integrate it into an urban setting with minimal environmental and social impacts. The innovative nature of the project won it the title of Desalination Plant of the Year at the Global Water Awards 2021; it also provides a model for others to follow.

In addition, the engineering phase of the plant’s construction involved some highly complex techniques to overcome issues such as thick marine clay, and underground construction adjacent to a busy expressway tunnel, while leaving undisturbed adjacent park connectors, which form an island-wide network of green corridors. At every stage, the plant has been designed and built with environmental considerations in mind, with the use of innovative technologies minimizing impacts on the public and occupants of the locality.

The groundbreaking development comes as efforts are underway to embed sustainability and resilience into strategies to tackle recovery and climate adaptation in cities around the world. Last year, for instance, the C40 Cities network, which works to address climate change in urban centers, published an agenda for a “green and just recovery” to rebuild and simultaneously improve public health, reduce inequality and address the climate crisis.

A technological world first for efficiency and resilience

Climate change is bringing ever-more erratic weather to Singapore and the new desalination facility, opened in February and known as the Keppel Marina East Desalination Plant, is the first and only one of the country’s four desalination plants to be located next to the central business district and surrounding residential areas, rather than areas further away from the city center. This means it is close to the source of demand, saving money on pumping water over distance.

More frequent dry seasons with low rainfall are increasing reliance on seawater desalination, which consumes more energy than other water treatment methods. Even during seasons of heavy rainfall, the amount of rainwater and stormwater that can be collected and treated into potable water is limited by the availability of containments within Singapore’s land area.

During wet periods, therefore, the plant’s dual-mode technology allows the option of switching to treating reservoir water, resulting in more effective water use, operational flexibility and optimized operational costs, because reservoir water treatment consumes only one-third of the energy required for seawater desalination.

As a result, the Keppel Marina East Desalination Plant can produce up to 137,000 cubic meters — equivalent to 54 Olympic-size swimming pools — of drinking water per day, regardless of weather conditions, ensuring a resilient and stable supply.

Making infrastructure work harder for urban sustainability

Not only is the Keppel plant efficient, but it blends neatly into the local environment, thanks to its structure being mostly situated underground. Meanwhile a 20,000 square meter green roof — with rainwater harvesting for irrigation — provides space for bike and walking trails for community recreation. In fact, seen with a satellite view, the plant looks like a park, rather than a desalination plant. Around 80 percent of its footprint is accessible to the public.

This dovetails with one of the key objectives in the C40 agenda to prioritize the building of “nature-based solutions,” to help reduce the risks of extreme heat, drought and flooding, and to improve livability as well as physical and mental health. Instead of a traditional industrial design that would become a barrier to community access, the Keppel Marina East Desalination Plant forms part of Singapore’s public park system and has become a place for people to gather to enjoy the green space and views. Ultimately, maintaining such green space in cities contributes to efforts to combat climate change by absorbing carbon and lowering urban temperatures.

The combination of resilience and sustainability — carried out in a cost-efficient manner — will increasingly be a key feature of how cities must approach climate adaptation as they seek to confront the effects of climate change on the most population-dense zones on the planet.

The art of partnership

A new framework for water resilience launched at World Water Week in August 2021 emphasized the importance of building partnerships between local and global, civil society and science and, crucially, public and private participants. Indeed, a public-private partnership was a vital aspect to the success of the Keppel Marina East project. The plant is a partnership between Keppel Infrastructure and Singapore’s national water agency PUB, with Keppel building and operating the facility under a Design Build Own Operate model and a 25-year water purchase agreement.

Such arrangements involving developer and operator are a highly effective way of approaching urban sustainability projects, because more effort tends to be invested in analyzing lifecycle costs and using the most efficient equipment possible. To Keppel, the partnership has yielded a number of good practices that could be replicated elsewhere, from detailed consideration of the construction sequence and environmental issues to its high level of automation. The outcome is a plant uniquely located among the population it serves, working efficiently and sustainably in a tight urban setting.