Every day, the Linggiu Reservoir does quiet battle with the ocean, feeding rainwater into the Johor River in southern Malaysia to keep its salt levels low enough to treat. Singapore, which built the reservoir in 1995, had been entitled to extract some 250 million gallons per day from the 123-kilometer-long river, meeting more than half its national needs. But a prolonged dry spell in 2016 saw reservoir levels fall to just 20% of capacity, leaving it shrunken and shallow.
“There was a real risk to our water supply,” Singapore’s prime minister, Lee Hsien Loong, later said. “It was a vivid reminder of why we have to be obsessed with saving water, and making every drop count.”
Water security isn’t a new concern for Singapore. The city-state’s tiny land mass and lack of natural lakes or aquifers have made water a priority ever since it gained independence in the 1960s.
“Though we are located near the equator and blessed with abundant rainfall, we are a severely water-stressed country due to a lack of land to collect and store all the rainwater that falls within Singapore,” explains Harry Seah, deputy chief executive for operations at the Public Utilities Board (PUB), Singapore’s national water agency. In 2015, the World Resources Institute ranked the country as among the most vulnerable to water stress, on a par with the arid states of Bahrain, Qatar, and Kuwait.
For decades, Singapore has satiated a significant amount of its demand through agreements to import water from neighboring Malaysia. One of those agreements expired in 2011. The second—the one that enables the country to draw water from the Linggiu Reservoir—is ongoing.
But that source is vulnerable—not only to drought but to politics. “In the past, there were multiple times when the relationship between the two countries [Malaysia and Singapore] had some friction, with water being a matter of dispute,” says Stuti Rawat, a postdoctoral fellow in the Department of Asian and Policy Studies at the Education University of Hong Kong. In 2018, Mahathir Mohamad, then Malaysia’s prime minister, signaled his plans to renegotiate the Linggiu agreement, calling it too costly and the current terms—which have Singapore paying just three sen (less than one cent) per thousand gallons—“manifestly ridiculous.” “Because of that, it has been very important for Singapore to try to carve out its own independent water supply,” adds Rawat.
The rise in global temperatures has added new urgency to the situation. “With climate change, we are expecting more extreme weather with more intense rain and longer dry spells, as experienced in the US, China, India, and many other parts of the world,” Seah says.
These volatile patterns mean that the country can no longer rely on rainfall to predictably fill up its reservoirs.
PUB has rallied households to conserve water. By 2023, it plans to have installed some 300,000 smart water meters in homes; they will use digital technologies to monitor usage and flag leaks.
But the country is also rapidly accelerating efforts to expand on its own water sources. PUB has committed to doubling the domestic supply of clean drinking water by 2060, a feat that would take Singapore close to self-sufficiency. Crucially, it aims to do so without increasing energy use.
The Keppel Marina East Desalination Plant, which sits on reclaimed land in the Marina East area of Singapore, is a sprawling monument to that effort. Opened in June 2020, the plant is capable of producing 30 million gallons of clean water every day. The facility, which was built with a government contract estimated at S$500 million (US$345 million), generates fresh water using significantly less energy than a typical desalination plant. That is because the plant operates in two modes, drawing in and treating rainfall that collects in a nearby reservoir during wet periods and processing seawater only when the weather is dry. Both sources are transformed into drinking water through a combination of ultrafiltration, reverse osmosis, and ultraviolet radiation.
The plant, one of the first in the world to use such a dual-mode system, is an example of how Singapore has continually “pushed the envelope” on water management, says JianYuan Ling, energy industries division manager for Singapore at ABB, the company behind some of the tech that underpins the plant. In doing so, it has challenged suppliers. “Efficiency is definitely their top priority,” Ling says. “This is a national project, so the whole country is watching.” But Keppel, he adds, is just “part of the grand plan” to make Singapore self-sufficient when it comes to water.
The other element is the country’s massive wastewater recycling campaign. Singapore already derives 40% of its water from wastewater. By 2060, it’s hoped, that contribution will have risen to 55%.
The jewel in the crown of this plan is the Changi Water Reclamation Plant, which opened in 2009. Much of the facility sits underground (some parts 25 stories deep), drawing in wastewater through a 48-kilometer-long tunnel linked to the country’s network of sewers. It’s capable of treating up to 900 million liters of wastewater a day using membranes to filter out microscopic particles and bacteria, reverse osmosis to remove tiny contaminants, and finally UV disinfection to destroy any viruses or bacteria that remain. The reclamation effort is “the key in helping us to overcome our land constraint for storage,” says Seah, referring to the fact that space to stockpile water in Singapore is in short supply.
The next step for Singapore is to further slash energy use. At a research and development facility in the industrial area of Tuas, for instance, PUB is testing new desalination technology that uses an electric field to pull dissolved salts from seawater, a less energy-intensive process than reverse osmosis. Also in development is a biomimetic membrane that uses natural proteins found in cells to accomplish the same task.
Such energy-saving strategies will be needed if Singapore hopes to achieve water independence. An expanding population and industrial growth are set to double water demand in the country by 2060.
Megan Tatum is a freelance features journalist based in Penang, Malaysia.
How we drained California dry
A story of remaking the land and taking the water until there was nothing left.
The rare spots of good news on climate change
It looks increasingly clear that we'll at least sidestep the worst-case scenarios.
How rising groundwater caused by climate change could devastate coastal communities
Higher sea levels will push the water table up with them, causing flooding, contamination, and all manner of unseen chaos.
The Atlantic’s vital currents could collapse. Scientists are racing to understand the dangers.
So far, the efforts to observe the currents directly show they're weirder and more unpredictable than expected.
Get the latest updates from
MIT Technology Review
Discover special offers, top stories, upcoming events, and more.