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.
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.
Under the 1962 Water Agreement, Singapore can draw up to 250 million gallons of water a day from the Johor River, and Singapore is obliged to provide Johor with treated water up to 2% of the water we import. The 1962 Water Agreement will expire in 2061. Constructed by PUB under a 1990 agreement with Johor supplementary to the 1962 Water Agreement, the Linggiu Reservoir is located upstream of the Johor River Waterworks and releases water into the Johor River to supplement its flow. This enables reliable abstraction of raw water at the Johor River Waterworks which is owned and operated by PUB for treatment.
The NEWater process recycles our treated used water into ultra-clean, high-grade reclaimed water, cushioning our water supply against dry weather and moving Singapore towards water sustainability.
Today, there are five NEWater plants supplying up to 40% of Singapore's current water needs. By 2060, NEWater is expected to meet up to 55% of Singapore’s future water demand.
In 2003, we launched NEWater to the Singaporean public, with the opening of the first two NEWater plants at Bedok and Kranji, and the NEWater Visitor Centre, a water museum to showcase our journey towards water sustainability.
Stage 1 – Microfiltration / Ultrafiltration:
The first stage of the NEWater production process is known as Microfiltration (MF) or Ultrafiltration (UF). In this process, the treated used water is passed through membranes to filter out microscopic particles and bacteria.
Stage 2 – Reverse Osmosis
The second stage of the NEWater production process is known as Reverse Osmosis (RO). In RO, a semi- permeable membrane is used. The semi-permeable membrane has very small pores which only allow very small molecules like water molecules to pass through. Consequently, undesirable contaminants including viruses cannot pass through the membrane.
Stage 3 – Ultraviolet Disinfection
After the RO stage, the water is already of a high grade water quality. The third stage of the NEWater production process is ultraviolet or UV disinfection which is capable of killing both bacteria and viruses. This process acts as an additional safety measure to guarantee the purity of NEWater.
Desalination is an energy-intensive water source. Singapore currently uses reverse osmosis for its desalination, which uses about 3.5kWh/m3 of energy to make seawater drinkable. This process produces pure drinking water by pushing seawater through membranes to remove dissolved salts and minerals.
Desalination, like NEWater, is a weather-resilient water source, that helps Singapore better cope with the threat of climate change. PUB has turned seawater into drinking water using advanced membrane technology, and we continue to invest in research and technology to find more efficient ways to desalinate seawater.
Currently, we have three desalination plants.
