With an area of about 710 km² and growing urban areas, Singapore lacks the space to collect and store all the rain that falls on it. Through a network of rivers, canals and drains, rain that falls on two-thirds of Singapore's land area is channelled to our 17 reservoirs.

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Two Separate Collection Systems

Singapore has two separate systems to collect rainwater and used water.  

1. Rainwater is collected through a comprehensive network of drains, canals and rivers and channelled to the reservoirs before it is treated for drinking water.

2. Used water is collected in a network of underground sewers that lead to a water reclamation plant. Separate systems ensure that the waterways are free of pollution.

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Harnessing Reservoirs and Rivers

Since 2011, the water catchment area has increased from half to two-thirds of Singapore’s land surface with the completion of the Marina, Punggol and Serangoon Reservoirs. This makes Singapore one of the few countries in the world to harvest urban stormwater on a large scale for potable consumption.  

PUB continues to explore ways to maximise our rainwater collection yield and strives to collect every drop of water that falls on Singapore. 

For more information on the development of local catchments, please click here [PDF]. 

Tracking Water Quality

PUB actively tracks the raw water quality in its reservoirs through sampling and online sensors. Regular water quality tests are also conducted on the raw reservoir water.

An iconic structure at the mouth of Marina Channel and the vision of the first Prime Minister of Singapore Mr Lee Kuan Yew more than twenty years ago, Marina Barrage creates Singapore’s 15th reservoir, Marina Reservoir.

At PUB, we believe that people who develop a relationship with water tend to treasure water and want to be guardians of it. We have witnessed increasing enthusiasm for watersports among the young and young at heart. Some of the popular water activities include canoeing, kayaking, fishing, radio-control electric boating and dragonboating.

While enjoying water activities, safety is paramount. For example, when canoeing, kayaking and dragonboating, life jackets must be worn at all times. People are also reminded to keep the catchment litter-free. 

For more information on guidelines of vessel, water activities and fishing, please click h​ere [PDF].

Minimising pollutants from the catchment is important for maintaining good water quality in waterbodies. Nutrients from sources (e.g. pet waste, food waste, fertilisers, detergents and sediments) in the catchment can have an impact on the reservoir's ecosystem. These nutrients are food for algae, which are microscopic aquatic organisms. These nutrients coupled with favourable conditions such as warm water and sufficient sunlight may encourage rapid algae growth.

For more information on why algae occurs, please click here [PDF].

PUB and NEA work as a team to monitor and control water pollution in our catchment. Through regular inspection and water quality testing, the team has built up a database that helps them identify potential pollution sources. If an area or a facility is found to be polluted, recommendations on better housekeeping practices and proper pollution control measures are provided to the venue owner.

During pollution incidents such as oil or chemical spills, the team will move in quickly to contain and remove the pollutant. Subsequently, with the help of observations from inspections and water quality data, steps are taken to trace the source and enforcement action may be taken.

Download brochures for more information on how you can play a part in Keeping Our Waters Clean.

Clean-up of Singapore River 

Did you know that Singapore River was once an open sewer? The clean-up of Singapore River was an effort by multi-agency over a period of 10 years. Click here to read more [PDF].

It is important to keep our catchment clean as that is a source of our water supply. The catchment is also a natural habitat of many creatures big and small. To preserve our ecosystem, we must not introduce non-native and/or aquatic creatures into the local environment. We may be doing more harm than good.

The Risk  

If alien species are released into our local waters, they may compete with native species for food, shelter and nesting areas. These non-native species may also prey on native species. 

Alien species may also carry viruses that can be deadly to the native species as they lack the immunity.   

Offenders will be Fined  

The release of animals and aquatic creatures into our reservoir parks and reservoirs is prohibited. To protect the balance of our ecosystem and safeward the water quality in reservoirs, offenders will be fined.   

Creatures Big and Small – Living in Pockets of our Blue Space 

Help us protect our environment and ecosystem and learn about the biodiversity of our reservoirs and waterways. 

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