Four National Taps, Singapore

Four different water sources provide a secure supply of water in this small, densely populated city state.

Singapore. Photo by William Cho.

Singapore. Photo by William Cho.

Taking a holistic view to managing the entire water cycle can help develop effective solutions for water supply and management.

Singapore is a small, densely populated city state and securing a supply of fresh water is a major challenge for the national water agency. The city has responded by developing a comprehensive water supply scheme, the Four National Taps strategy, over the last 40 years.

Diversifying the water supply

The strategy uses four different water sources:

  • Water catchment
    Half of the land in Singapore is covered by a rainwater collection network. Storm water ponds beneath flyovers collect rainwater for reservoirs. The marina basin has been converted into a freshwater reservoir to supply 10 per cent of Singapore’s water.
  • Recycled water
    Wastewater is treated to produce NEWater. NEWater is drinkable but is predominantly used by industries requiring high purity water. It should meet 30 per cent of Singapore’s water demand by 2011.
  • Desalinated water
    The first desalination plant opened in 2005 and is one of the biggest and most energy efficient in the world. It meets 10 percent of the country's water needs.
  • Imported water
    Singapore still has to import water from neighbouring Malaysia, but thanks to the alternative water sources dependency on foreign water is falling.

Singapore is also reducing water demand using education campaigns, water-saving devices in people’s homes, a water efficiency labelling scheme and a pricing system that encourages people to use less water.


As a result, Singapore has access to better water supplies and has a thriving water industry that wins international contracts. The country won the Stockholm Industry Water Award in 2007.

Tags: water, cities and towns

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