Singapore has no natural lakes and no major rivers, yet it operates one of the most developed urban water systems in the world.
The country’s total land area is about 735 square kilometers, making large scale freshwater storage difficult. At independence in 1965, Singapore relied heavily on imported water from Malaysia.
Under the 1962 Johor-Singapore Water Agreement, which allowed Singapore to import up to 250 million gallons of raw water per day from Johor. This agreement remains one of the foundations of Singapore’s water supply system.
Why Water Became a National Priority
At independence, Singapore had limited freshwater catchment areas and a rapidly growing population.
Singapore’s dependence on imported water was formalized through two major agreements with Johor. The first agreement was signed in 1927 between the British controlled Municipality of Singapore and the Sultanate of Johor, while the second was signed in 1962 and remains valid until 2061.
According to Singapore’s national water agency Public Utilities Board (PUB), ensuring water security became a central state priority in the late 20th century. Over time, Singapore expanded water collection infrastructure by converting urban waterways into reservoirs and building dams across river mouths.
The Four National Taps
Singapore’s water supply system is built upon a strategic framework known by the government as the Four National Taps.
Comprises local catchment water, imported water, NEWater (high grade reclaimed water), and desalinated water. This multifaceted approach was introduced to diversify the nation's water sources and significantly reduce its dependence on foreign imports.
According to PUB, these four distinct sources collectively satisfy Singapore’s current daily water demand of approximately 430 million gallons (1.63 billion liters), a figure that is projected to nearly double by the year 2060.
How NEWater Changed Singapore's Supply
NEWater was launched in 2003 as Singapore’s large scale recycled water program.
It uses advanced membrane filtration, reverse osmosis, and ultraviolet disinfection to treat used water into ultra clean water.
According to PUB, NEWater currently meets up to 40% of Singapore’s total water demand.
By 2060, this is projected to increase to 55%. Most NEWater is supplied to industrial users, while some is blended into reservoirs for indirect potable use.
NEWater reduced Singapore’s dependence on imported water and expanded domestic supply capacity.
Desalination and Reservoir Expansion
Singapore also expanded desalination capacity as part of its long term planning.
Its first desalination plant opened in 2005. As of today, Singapore operates multiple desalination plants, which can meet up to 30% of national water demand. By 2060, desalination is expected to contribute around 30% of total supply.
The country also developed 17 reservoirs, including Marina Reservoir, created after the completion of Marina Barrage in 2008. Marina Barrage converted part of Marina Bay into a freshwater reservoir, increasing urban water storage capacity in central Singapore.
Reducing Imported Water
Singapore’s long term strategy has reduced its reliance on imported water.
By combining reservoirs, recycled water, and desalination, Singapore has increased domestic production capacity significantly over the past two decades.
Over the following decades, Singapore aggressively expanded its domestic water collection by damming rivers, building reservoirs, and optimizing urban drainage. This effort successfully grew the country’s catchment area from a limited share of land in the 1960s to more than two thirds of its total territory.
Today, despite having no natural lakes, Singapore maintains a highly diversified water system built on local collection, recycled supply, desalination, and imports.
