Cities + Water: Singapore

When it comes to water management, Singapore embodies the cliche that “necessity is the mother of invention.”

According to the World Resources Institute (WRI), Singapore is the fifth most-likely country to experience extremely high water stress by 2040. In part, this stems from Singapore being one of the most densely-populated countries in the world, housing around 5.5 million people on a land area of just 733 square kilometers – smaller than that of New York City.

It’s also due to the tiny island being extremely low-lying, with its highest point reaching just 164 meters and most of its area sitting at less than five meters above the mean sea level. There’s high rainfall during the wet season but little groundwater, and only limited amounts of land are available for water storage facilities. When it rains heavily, the largely urban, concreted environment faces significant flood risks; and when it’s dry, water supply is a major issue. 

 “Water is such an existential matter in Singapore: we have to live and breathe it all the time,” says Harvey Neo, a senior fellow and program head at the Lee Kuan Yew Centre for Innovative Cities at Singapore University of Technology and Design.

Yet the country has risen to the challenge. With integrated, long-term planning – and constant modification and improvement – the ambitious, prosperous city-state has become a model for effective urban water management. The city-state’s high level of governmental control might sometimes spark international incredulity – for instance, for the notoriously well-enforced laws against chewing gum, litter and jaywalking – but it comes in handy for dealing with scarce resources. “It’s a very enlightened place,” says Cecilia Tortajada, a professor in environmental innovation at the University of Glasgow who specializes in water management and has been following developments in Singapore for the past 15 years.

While acknowledging the important comparative advantage offered by the city-state’s high annual rainfall, she says that what sets Singapore apart from other places facing similar challenges is the genuine, high-level coordination and collaboration between resource management sectors. “Every country’s ideal is coordination, but it doesn’t happen in most places. It does, however, happen in Singapore. There are clear decision-making processes for land use, and they play out according to the plans.”

The four ‘national taps’

According to Singapore’s Public Utilities Board (PUB), which coordinates the supply of electricity, water and piped gas, the country has four National Taps, or water sources: rainwater, imported water from Malaysia, high-grade reclaimed water termed ‘NEWater,’ and desalinated water.

At present, imported water from the Johor River in Malaysia represents up to half of Singapore’s total water usage. But policymakers in Malaysia are increasingly reluctant to maintain this situation, and Singapore’s rights to draw the water will end in 2061. So, PUB is working to level up inputs from the other “taps” before that occurs. “For a long time, water sourcing was not a huge issue, because we were simply buying a lot of it from Malaysia,” says Neo. “And we’ve always relied on that relationship. But the federal politics of Malaysia have changed, and we’ve had to think more about other solutions.” 

Two-thirds of the country’s land area is put to work as a catchment for rainwater, and PUB, according to its website, continues to strive toward the goal of “collecting every drop of water that falls on Singapore.” That means making use of the likes of roofs of high-rise buildings and run-off from airport runways for rainwater harvest. Between 28 and 33 percent of all water used at the country’s Changi Airport, for instance, is rainwater that’s captured and treated onsite, saving the airport an estimated USD 275,000 per year.

NEWater is created by collecting and carefully treating the country’s sewage and wastewater for reuse. NEWater currently supplies around 30 percent of total water demand, and PUB aims to up this to 55 percent. Tortajada points out that such a system could only be effective in a place where trust in government is high, as it is in Singapore. “If you ask people there whether they trust the recycled wastewater, they look at you like, ‘of course!’” she says. “So [PUB] is trusted to that point.” Neo confesses he personally feels “a little bit iffy about [using recycled sewage and wastewater], but we have no say over this – it’s in the water supply whether we like it or not.”

Desalination, the final National Tap, supplies about a quarter of total water demand through its four active desalination plants, and PUB hopes to up this to 30 percent by 2060. Conventional desalination processes, however, are highly energy-intensive, so the institution is working on ways to make them more efficient, such as through electro-deionization (using an electrical field to pull dissolved salts through water) and biomimicry (mimicking the low-energy processes by which mangrove plants extract freshwater from seawater).

Water-wise infrastructure and population

In 2000, Singapore’s water consumption was 165 liters per person per day. In 2018, it had dropped to 141 liters. PUB hopes to get it down to 130 liters by 2030.

Consciously saving water – through legislation, design, incentives and education – has been central Singapore’s management strategy. Only highly water-efficient domestic appliances (such as washing machines, showers and dishwashers) can be sold in the country. In public housing complexes, where almost 80 percent of Singapore’s residents reside, the pipes installed in kitchens and bathrooms are narrower than those used in countries such as the U.S., which also cuts water use considerably. Technologies like motion sensor taps stem wastage even further.

Outside the home, city planners carefully control water-hungry land uses. “For instance, we used to have a lot more golf courses,” says Neo. “But those require quite a bit of water, so in recent years we haven’t renewed the leases for most of them.”

Pricing water – at levels that people in other countries would likely consider very high – is another key part of the strategy. “It’s not just a retrieval cost,” says Neo. “It’s a kind of existential cost as well. So it’s punitive… The more water you use compared to households of a similar size, the more you will be taxed.”

Water conservation education, which has been in places for decades, is also a critical part of the equation. “Singapore is a bit different in terms of how strongly people hold this idea of the importance of water, its value and how it’s a precious commodity,” says Neo. “It’s been inculcated into us from a young age – from when we were 4 years old at kindergarten and right the way through the school system. Even back when I was young, it was not like we just took a course on water: it was sprinkled through all of our learning.”

Adaptation and innovation

A key strength of Singapore’s system is that it’s very responsive to feedback, says Tortajada. “When [the government] gets things wrong, they change them very quickly,” she says. “And it’s unlikely that, in Singapore, they will be wrong on something more than two times.”

This constant innovation will likely prove even more important in the coming decades, given the growing uncertainty of weather patterns as the climate changes. However, Neo is optimistic about the resilience of the current approach. “We’ve tried a lot of things, and we’ve now reached a sort of status quo in terms of our management of water,” he says. “And I think that it probably will continue to work going forward – we’ve devised a very comprehensive management, harvesting and water-use system that I think we can depend on for the near future.”

This article is part of a series on cities and water management. Read about Santiago here and Cape Town here.