Water

Singapore is amongst the most water-stressed countries in the world. This is due to the lack of natural water resources such as large rivers, natural springs or glaciers, as well as limited land to collect and store rainwater.

Through careful planning and innovation, we have been able to build a robust, diversified and sustainable supply of water over the decades with our Four National Taps:

Water from Local Catchment

Rainwater is an important source of water for Singapore and forms one of our Four National Taps.

In land-scarce Singapore, we have limited land to collect and store rainwater. To make the best use of the rainfall we receive, the water catchment area in Singapore has been progressively expanded over the years.

About two-thirds of Singapore's land surface serves as water catchment area. Rainwater that falls within the water catchment is collected and channelled via a network of more than 8,000 km of drains and canals, to 17 reservoirs for storage before it is treated for drinking at our local waterworks.

Imported Water

Singapore imports water from Johor under the 1962 Water Agreement between Singapore and the Johor State. This agreement entitles Singapore to draw and use up to 250 million gallons of raw water per day from the Johor River. In return, Singapore is obliged to provide Johor with treated water up to 2% of the water we import. The agreement expires in 2061.

NEWater

Introduced in 2002, NEWater is produced through a 3-step treatment process (microfiltration, reverse osmosis, disinfection) using advanced membrane technologies. It has passed through more than 150,000 scientific tests and is well within the World Health Organisation guidelines for Drinking - Water Quality. As a weather-resilient source, NEWater plays an important role in enhancing the resilience of our water supply.

We have successfully closed the water loop by recycling used water to become high-grade reclaimed water known as NEWater, allowing us to reuse every drop of water. There are currently four NEWater factories in Singapore.

Desalination

Desalination is the removal of dissolved salt and minerals from seawater to make it potable.

Advances in membrane technology have made it viable for desalinated water to be one of our Four National Taps. In Singapore, desalination is done through a process called reverse osmosis, which separates water from dissolved salts and minerals.

We now have five desalination plants in operation. PUB is carrying out a feasibility study for a potential sixth desalination plant.

Weather-resilient Water Sources

NEWater and desalinated water are weather-resilient water sources and will help strengthen Singapore's water security.

Water demand is expected to almost double by 2065. To meet this growing need, we have to continue planning ahead, innovating and investing in research and development of more efficient water treatment processes to ensure the long-term sustainability of our water resources.

Difficult to Create New Reservoirs

All major estuaries in Singapore have already been dammed up to create reservoirs. While we still have some untapped streams and rivulets near the coastline, they are too small to dam up as reservoirs.

Rainfall Patterns are Unpredictable

Climate change may result in unpredictable rainfall patterns. We cannot rely solely on rainwater collected by our reservoirs to meet the water needs of our population and economy.

Possible Pollution from Urban Development

It is a challenge to keep the rainwater collected clean, as Singapore’s small size means that much of our urban development is near or within water catchment areas. Many human activities produce pollutants that can be carried via the drainage system into our reservoirs when it rains, affecting reservoir water quality.

Such pollution makes it more costly to process and supply clean water to our taps.

Keeping Our Water Clean

Our waterways are cleaned regularly. We use float booms and litter traps to prevent litter from entering our reservoirs.

We have also put in place measures to keep our reservoirs clean. For example, an underground wall was built along the former Lorong Halus landfill, which forms part of the bank of Serangoon Reservoir. The wall prevents water from the landfill from seeping into the reservoir. Instead, this water is collected and treated on-site by passing them through specially selected reed beds and ponds, before it is discharged into the sewerage system.

Beyond these measures, everyone has a part to play in keeping our waterways clean and free from pollutants.

Seeking Cooperation from Public and Private Sectors

We rely on everyone to help keep our water clean. Individuals have to help keep our drains, rivers and reservoirs clean by not littering. Construction companies have to ensure that soil from worksites does not get washed into our drains, and factories have to ensure that waste chemicals are not discharged into our drains.

It is also important for industries to play their part by complying with the Sewerage and Drainage Act and the Environment Protection and Management Act, to ensure that waste is properly disposed of and substances such as silt and chemicals are not washed into waterways.

PUB's Active, Beautiful, Clean (ABC) Waters Programme transforms our waterways and reservoirs into recreational spaces which people can value and enjoy, bringing people closer to water so that they can better appreciate and cherish this precious resource.

ABC Waters design features are incorporated to create both beautiful and clean waterways for all to enjoy. These include bioretention systems that help to cleanse the rainwater as it flows through our waterways.

As part of the ABC Waters programme, many of our waterways and reservoirs are now open to a variety of recreational water activities such as canoeing, dragon-boating, kayaking and sailing.

Introduced in 2002, NEWater is produced through a 3-step treatment process (microfiltration, reverse osmosis, disinfection) using advanced membrane technologies. It has passed through more than 150,000 scientific tests and is well within the World Health Organisation guidelines for Drinking - Water Quality. As a weather-resilient source, NEWater plays an important role in enhancing the resilience of our water supply.

As it is ultra-clean, NEWater is used mainly for industrial and air-con cooling purposes at water fabrication plants, industrial estates, and commercial buildings.

The biggest users of NEWater are wafer fabrication plants, which require water quality that is even more stringent than water for drinking. NEWater is delivered to industrial customers via a dedicated pipe network.

During dry periods, NEWater is added to our reservoirs to blend in with raw water. The raw water from the reservoirs is treated at the waterworks before it is supplied to consumers as tap water.

Used water is a precious resource to Singapore as it is used to produce NEWater. The discharge of trade effluent containing prohibited substances or excessively high concentrations of regulated substances will impact the used water treatment operations at Water Reclamation Plants (WRP) and the production of NEWater. PUB monitors these discharges closely.

It is important for industries to play their part by complying with the Sewerage and Drainage Act and Sewerage and Drainage (Trade Effluent) Regulations.

Desalinated Water is Costly

Desalinated water is more energy-intensive and costly than NEWater, but is necessary as a weather-resilient source and one of our Four National Taps.

Technology Provides Solution

We continue to invest in research and development to reduce the energy consumption and cost of desalination to ensure the sustainability of desalinated water. These include technologies such as ultra-permeable membranes and ceramic membranes.

Limiting The Impact On The Marine Environment

We closely monitor the quality of sea water surrounding our desalination plants to make sure there is minimal impact on the marine environment.

Increasing Demand and Climate Change

Singapore consumes about 440 million gallons of water per day, and the total water demand is expected to almost double by 2065 as a result of projected increases in industrial activity and population growth. Coupled with the uncertainty of weather patterns in the face of climate change, we must do all we can to ensure the sustainability of our water resources.

Wasteful Habits

In Singapore, we are fortunate to have easy access to clean water. However, this also makes it easy for us to use more water than we really need. When clean water comes at the turn of a tap, it is easy to take water for granted and waste this precious resource without noticing.

Unrepaired Leaks

Water wastage from pipes or water appliances often goes unnoticed. Loose tap fittings, malfunctioning toilet cisterns and leaking water pipes can all lead to a huge waste of water.

For instance, a typical leak from a kitchen can amount to 10,000 litres per year, which is over 6,600 large bottles.

Reduction in Water Consumption

Through our long-term efforts in water conservation, Singapore's household water consumption dropped steadily from 165 litres per capita per day (LPCD) in 2003 to 141 LPCD in 2019.

Household water consumption increased sharply during the COVID-19 pandemic - 154 LPCD in 2020 and 158 LPCD in 2021. This was a result of people spending more time at home due to safe management measures and work-from-home arrangements, and an increased emphasis on hygiene.

Following the relaxation of COVID-19 safe management measures and resumption of business activities, the household water consumption returned to pre-pandemic levels of 141 LCPD in 2023, and has remained stable around this level since. We will continue our efforts to encourage water conservation.

Water Conservation Education and Outreach

PUB engages in community outreach efforts to raise awareness. These include the annual water conservation campaign to reinforce the importance of water conservation, and Singapore World Water Day celebration in the month of March to rally the community and drive continued awareness on the importance of water conservation and sustainability, through a variety of community and ground-up events.

Preventing and Detecting Leaks

PUB replaces ageing water mains and pipes in its network over the years to minimise leaks. Regular checks are also conducted on water meter readings, and on water mains and pipes using technologies such as leak monitoring sensors and inline pipe inspection tools, to detect leaks.

Pricing Water to Reflect Its True Value

The price of water in Singapore reflects its scarcity value. The use of sound economic principles in pricing water is important to keep demand and supply in balance. Under-pricing water leads to over-consumption. In Singapore, water is priced to recover the full cost of its supply and production, and to reflect the cost of producing the next drop of water, which will be from NEWater and desalination.

Mandating Water Efficiency Requirements

The Mandatory Water Efficiency Labelling Scheme and minimum water efficiency standards for water fittings and appliances help consumers and businesses make more informed choices, and encourage suppliers to introduce more water-efficient fittings and appliances into the market.

Large water users in the non-domestic sector are required to submit water efficiency management plans to PUB annually. This requirement encourages companies to better understand and manage their water usage, and has allowed PUB to develop water efficiency benchmarks and best practice guidelines using the data collected.

Since 2024, mandatory water recycling requirements have been introduced on new and expansion projects in the water-intensive wafer fabrication, electronics and biomedical industries. Wafer fabrication plants involved in front-end semiconductor manufacturing will need to meet a minimum recycling rate of 50%, while electronics plants and biomedical plants will be required to recycle specific waste streams.

Funding Water Efficient Measures

PUB's Water Efficiency Fund (WEF) co-funds organisations, companies and community groups to implement water saving initiatives such as water recycling projects and the adoption of water efficient equipment. Since 1 July 2023, PUB has raised the funding cap for water recycling projects under the WEF from $1 million to $5 million, as part of its continuing efforts to drive water conservation efforts and promote the sustainable water management practices in the non-domestic sector.

Beach water is vulnerable to contamination from pollutants. During water activities at the beach, we will come into contact with seawater and may ingest it accidentally. Should the water quality be poor or contaminated, this may lead to gastrointestinal and respiratory illness.

Contamination at our beaches could originate from multiple sources, such as discharges from bin centres, food establishments, and construction sites. Improper hygiene and waste management practices such as pouring wastewater into public drains could impact the water quality in our waterways.

Beach Goers Must Play Their Part

While beach goers enjoy their time at the beach, they should take care not to leave rubbish behind when they leave, which could contribute to the pollution of beach water.

Singapore's recreational water quality guidelines are adopted from World Health Organisation (WHO) guidelines for Safe Recreational Waters. The local guidelines were established in 2008 after a careful study of the WHO guidelines, analysis of data gathered over a few years, and consultation and collaboration with other relevant agencies.

NEA grades our recreational beaches based on the WHO guidelines twice a year. If any beach is graded “Fair” or poorer, NEA will put up an advisory against swimming and other primary contact activities for the beach. The grading results are published on NEA’s website. 

In addition to the biannual beach water quality grading, NEA also collects and tests water samples at our recreational beaches weekly, to detect potential spikes in contaminants. Beachgoers are encouraged to refer to the weekly Beach Short-term Water Quality Information (BSWI) (opens in new tab) on the NEA website or myENV app before engaging in water activities.

NEA also has regular cleaning regimes for our beaches to remove litter from our beaches and coastlines. The frequency of clean-ups ranges from four times a week to once in two weeks, depending on public usage and accessibility to the beach.

More information on Singapore's water quality guidelines for recreational beaches, as well as updates on the latest beach gradings and advisories can be found here. (opens in new tab)

As climate change brings about more extreme weather events, we are likely to see more flash floods from intense rain.

We have an extensive drainage system comprising 8,000km of drains, rivers and canals that channel rainwater to our reservoirs or the sea. Most times, our drains can cope with the rain that we receive. However, intense bouts of rainfall can sometimes exceed the capacity that the drains are designed for, resulting in flash floods. These floods are mostly localised and subside within an hour.

To better mitigate against floods, PUB is enhancing our drainage system and have mandated large developments to implement on-site detention measures (such as detention tanks and rain gardens). Developments must adhere to PUB's requirements such as minimum platform levels and minimum crest levels to minimise flood risk. Community resilience is also key to strengthening our collective response to floods.

Upgrading and Maintaining Drainage Infrastructure

PUB continually upgrades existing drainage infrastructure to cater for new developments, alleviate flood risks and rehabilitate aging infrastructure. These include widening and deepening our drains and canals, constructing diversion canals and catchment level detention tanks. Structural repairs of drains and canals are carried out where necessary to ensure that they continue to function effectively. We also regularly review the adequacy of our drainage infrastructure, taking into account the latest drainage design standards and climate projections.

Legislation

We work closely with building owners and developers on measures that have to be taken at the individual development level to strengthen flood resilience, such as to regulate the run-off of stormwater into drains during heavy rain and to protect infrastructure from flooding. It is also important for owners and developers to continue operating and maintaining the flood protection measures in their premises after implementation, in compliance with the Sewerage and Drainage Act.

Strengthening Community Resilience

While we have made significant progress in reducing flood risks in Singapore, it is impossible to eliminate floods entirely. In land-scarce Singapore, we cannot continually expand drainage infrastructure every extreme rainfall scenario. Strengthening community resilience is therefore essential in mitigating the impacts of flooding. This includes raising awareness of flood risks, fostering understanding that floods may happen from time to time, and encouraging communities to take proactive steps in planning and protecting against flooding. PUB supports the community with its forecasting and warning services, which provide timely information to the community to help them better prepare and respond to flood incidents, as well as by distributing flood protection devices.

Flood Response

To improve flood monitoring, PUB has installed an extensive network of water level sensors at major waterways and drains, as well as CCTVs at flood-prone areas and hotspots. During heavy rain events, PUB’s flood response vehicles and Quick Response Teams (QRTs) are deployed to potential flood locations to keep the public out of harm’s way. The vehicles, with their mounted LED signs and blinker lights, are also able to drive through higher floodwaters to close off flooded road sections and divert traffic. Flood protection devices, such as portable flood barriers and inflatable flood bags, stored in the vehicles can be quickly deployed to divert water away from roads or residents’ homes.

In addition, the public can get timely updates on potential floods through multiple platforms such as the Telegram flood alert channel (opens in new tab), “MyENV” mobile application, and social media platforms (e.g. Facebook (opens in new tab) and X (opens in new tab) (formerly known as Twitter)), so that safety precautions can be taken.