How Singapore gets clean water

Goh Jun Cheng

Singapore has transformed itself from a country with limited, polluted water resources at independence to one that is now a global leader in water management.

With few natural freshwater sources, Singapore had to find unconventional solutions to quench the thirst of its growing population and economy.

Today, through massive infrastructure investments, technology and innovative policies, Singapore has achieved a diversified, sustainable water supply despite its limitations as a dense city-state.

This article provides an in-depth look at Singapore’s water sources and how it has become self-sufficient in one of life’s most precious resources.

Singapore’s Water Challenges

Singapore has faced monumental water challenges since its inception in 1965. It has a land area of only 724 square kilometers and no major aquifers or natural lakes.

Local water resources comprised only rivulets, a few reservoirs and limited groundwater. Yet Singapore’s population grew rapidly from 1.9 million at independence to 5.7 million today.

Providing water became an existential issue for the government. Singapore also lacked freshwater sources, with its rivers badly polluted in the 1970s.

Water had to be imported from neighboring Malaysia. But supply from Malaysia was unreliable and at risk of being politicized. Solving its water constraints was thus critical for Singapore’s survival and growth.

Four National Taps Strategy

In response, Singapore developed and implemented an integrated long-term water strategy from the 1970s onwards centered on diversifying its water sources.

The Four National Taps strategy focused on: importing water, using local catchment water, recycling used water (NEWater) and desalinating seawater.

By combining all 4 taps, Singapore aimed to ensure a robust, sustainable water supply despite having no natural aquifers or lakes. Let us examine how each of these water taps functions and contributes to Singapore’s water security.

Imported Water

Singapore imports a significant portion of its water needs from neighboring Malaysia.

Under two bilateral agreements in 1961 and 1962, Singapore was granted rights to draw 250 million gallons per day (mgd) of water from the Johor River that flows through both countries.

Singapore later supplemented this with another 350mgd of water from the Linggui Reservoir in Johor. Two pipelines transport imported water from Malaysia to Singapore.

Treated at Singapore’s water plants, imported water provides about 40% of the country’s current water needs. However, Singapore has long recognized the risks of relying on transboundary water.

Thus reducing water imports was a priority. NEWater and desalination have allowed imported water levels to fall from full capacity.

Still, imported water remains vital today as Singapore builds up its drought resilience.

Local Catchment Water

Despite having limited freshwater resources, Singapore developed a sophisticated catchment system to harness water from rainfall and runoff within its own territory.

Singapore dammed rivers and directed water via drains, canals and tunnels into a network of 17 reservoirs. Active, optimal management maximizes catchment yield.

Today, local catchment water accounts for about 30% of Singapore’s needs. Expanding reservoir storage capacity through engineering innovations remains a focus, including at reservoirs like Marina Barrage.

Catchment infrastructure intercepts and diverts stormwater and tidal streams to reservoirs before discharge. NEWater is also added to reservoirs.

While limited geographically, meticulous management enables Singapore’s local catchments to contribute significantly.


With water demand rising but opportunities to expand supply limited, Singapore pioneered NEWater to boost water resources.

NEWater is ultra-pure recycled water produced from an advanced, multi-stage treatment process. Treated used water is passed through microfiltration, reverse osmosis and ultraviolet disinfection to raise it to drinking water standards.

NEWater is mainly used by industries requiring ultra-pure water like wafer fabrication plants. Blending NEWater with raw reservoir water before conventional treatment also creates drinking water.

NEWater currently meets up to 40% of Singapore’s water demand. With new technology, Singapore aims to raise NEWater’s contribution further.

For instance, electrochemical processes now enable nutrient recovery from wastewater. Boosting NEWater production enabled Singapore to reduce water imports and improved self-sufficiency.

Desalinated Water

To diversify further, Singapore taps seawater desalination. With coastal borders but limited freshwater, using the sea for water made strategic sense.

Singapore opened its first desalination plants in 2005 using reverse osmosis technology. Desalination plants at Tuas, Marina East and Jurong Island now supply up to 30% of Singapore’s water needs.

Expanding desalination capacity helps reduce reliance on imports. Desalination also provides a drought-resistant source unlike rainfall.

But desalination is energy intensive. Singapore mitigates this by locating plants near power stations to utilize waste heat.

While energy-thirsty, adding desalination allowed Singapore to turn its maritime location into an advantage for water independence.

Water Demand Management

Expanding supply was coupled with managing water demand judiciously.

Singapore adopted a holistic approach combining pricing, regulations, technology and outreach to instill water conservation habits. Water pricing based on usage discouraged excessive consumption.

Fixtures also had to meet efficiency standards. Public education campaigns like the “Make Every Drop Count” initiative raised awareness on valuing water.

Smart metering tracked usage. Leak detection and preventive maintenance reduced water losses.

With no aquifers to draw from, managing demand helped balance supply prudently. Per capita domestic water usage fell from 165 liters in 2003 to 141 liters in 2020 through conservation efforts.

Institutional Framework

Undergirding these efforts is an integrated institutional framework.

The Public Utilities Board as national water agency handles water management from catchments to treatment.

The Ministry of the Environment and Water Resources (MEWR) sets policies and long-term plans. For example, MEWR’s “Our Water, Our Future” blueprint mapped out water resource development from 2000-2030.

Adopting a whole-of-government approach enabled coordinated infrastructure development. Strong political will to become self-sufficient in water drove investments like Tuas Desalination Plant – one of the world’s largest.

Foresighted water management became an existential priority for Singapore.

Investing in R&D

At the same time, Singapore invested heavily in water R&D to develop innovative solutions. Government agencies, universities and companies collaborate on a wide spectrum of water research at the national Environmental & Water Technology Centre of Innovation.

Singapore companies have commercialized a range of technologies from ultrafiltration membranes to desalination systems. With limited conventional water, investing in R&D helped Singapore tap unconventional sources like NEWater safely and sustainably.

Becoming a global water hub also created economic opportunities in water tech exports and services.

Regional Collaboration

Despite its efforts, Singapore recognized that water remains an existential issue. So it continues to explore collaborative approaches in line with its regional foreign policy.

Singapore engages ASEAN partners on spurring water infrastructure investments through its Sustainable Singapore Gallery. It also entered into commercial water agreements with Indonesia.

One innovative project is an exchange where Singapore provides treated wastewater to Batam, Indonesia, which supplies Singapore with raw water in return. Pursuing foreign partnerships enhances Singapore’s long-term water security.


Lacking natural freshwater reserves, Singapore demonstrated ingenuity in becoming self-sufficient in water.

Through an integrated Four National Taps strategy leveraging technology, infrastructure development, efficient policies, R&D and regional collaboration, Singapore surmounted extreme land and resource constraints.

While not entirely water independent yet, its combination of supply augmentation and demand management provides a hedge against droughts.

Singapore’s holistic approach to water resource planning holds lessons for other water-scarce cities worldwide.

Its success also shows that with political will, investments and innovation, severe lack of natural water sources need not impede a small island nation’s progress.

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