Lessons from Singapore
How Singapore manages its water requirement is a lesson for all urban areas in India
Good show: A bottle of recycled water
Being an island nation, Singapore’s water resources, like many other resources, tend to be limited. With a population of 3.80 million and a land area of 699 square kilometres, it is officially a ‘water stressed’ nation as it has less than 1,000 cubic metres per person per year as water availability.
Its average rainfall of 2400 mm per year gives its only internal fresh water resource and it imports 40 per cent of its water needs from neighbouring Malaysia. How Singapore manages its water requirement is a lesson for all urban areas in India.
The 4 taps strategy
The key to its water management is what it calls the “4 taps water strategy.” The taps include its own catchment management and water harvesting in reservoirs; buying water from Johore, Malaysia; desalination plants to supply water; and recycling wastewater through its ambitious and innovative NEWater plants.
The first tap is to harvest rainwater which falls on its land and to store it in reservoirs. Approximately 60 per cent of Singapore is now a catchment for its own water reservoirs.
Whereas previously most rainwater would flow into the sea, now it is channelised to be collected in 14 reservoirs kept away from sea waters, treated and supplied back to the city. While previously stormwater channels were simply concrete drains designed to flush out the heavy downpour, they are now being treated ecologically to encourage softer landscapes, flora and fauna and to increase the biological propensity which natural rivers have as compared to concrete drains.
The entire 32 rivers, 7000 kilometres of canals and drains will slowly be restored ecologically, starting with the Singapore and Kallang rivers. The goal is to make it possible for fish to be back in these rivers. By the end of 2009, 17 reservoirs will be in place and nearly 70 per cent of the city will become the catchment for these reservoirs.
The second tap is water brought from Malaysia which contributes currently to 40 per cent of its requirements.
Two agreements for water purchase signed in the 1960s have tended to become contentious at times but also have withheld all stresses and strains and never has Malaysia stopped water supply to Singapore. One of the agreements will come up for renewal in 2011 and the other in 2061. With deft diplomacy and as a commitment to good neighbourly relations Singapore will continue to source water from Malaysia.
In the meantime it has also signed an agreement with its other neighbour, Indonesia, to purchase water from it in the future.
The third tap is recycled sewage water called NEWwater. Three wastewater recycling plants recycle close to 90 million litres per day. This recycled water is put back in the fresh water reservoirs, treated further and supplied back to the city for all its requirements.
Treated wastewater is put through a further three-step process of membrane-based ultra filtration, reverse osmosis and ultraviolet treatment before being sent to reservoirs. Around 20,000 tests were conducted before the water was found fit for consumption.
It is gradually being integrated into the city’s water requirements through first for non-potable purpose use and also through its blending with reservoirs for potable water use. Bottled NEWater is also available in supermarkets for consumption to assure consumers of safety and taste.
The fourth tap is desalination. The first desalination plant was commissioned in 2005 with a capacity to produce 136 million litres of desalinated water per day which is about 10 per cent of water requirements. By 2011 desalination will provide 400 million litres of water per day or roughly 30 per cent of Singapore’s water requirement.
With a water demand of around 1,400 million litres per day and limited natural resource, Singapore has focused on multiple sourcing of water including rainwater harvesting, purchasing water, recycling treated sewage water and desalination. Through appropriate water tariff, water demand per capita has been held at 163 litres per person per day.
Every household is connected to the sewage network and wastewater is treated to potable standards. It is moving more and more towards self-sufficiency with an ecological and technological approach towards water management.
In future times, urban areas in India will also need political skills of managing water, a professional managerial approach to make technological choice, an ecological approach to rivers, streams, lakes and ground water to maintain water quality and a vision of self sufficiency. Only then will water wisdom prevail and water for all become a reality.