The ‘four taps’ approach

Singapore is a model for water management, and our cities can learn a lot on how best to tap nature and technology. By S.Vishwanath

Published - June 28, 2019 05:55 pm IST

Most of Singapore is designed as a catchment to collect rainwater.

Most of Singapore is designed as a catchment to collect rainwater.

One city-state that has become the model for water management is the island of Singapore. The population is about 5.60 million, spread over 760 The ‘four taps’ approach has helped Singapore become water sustainable and aspirational for other cities. What are these four taps and what are the lessons for Indian cities?

The first tap is sourced water or water from far. In the case of Singapore, it is water bought from Malaysia. The second tap is water from local catchment. Most of the city is designed as a catchment to collect rainwater. The stormwater drains then lead the rain into many storage reservoirs. From the storage reservoirs water treatment plants treat the rainwater to be supplied to the city as potable water.

The third tap is desalination. Water from the sea is desalinated and supplied to the city.

The fourth tap is treated wastewater or as Singapore calls it NEWater. Wastewater is treated to such high standards that it can be drunk. For the moment this treated wastewater is used for industrial purpose and for blending it with rainwater in the reservoir before being supplied to the city.

For our coastal cities, the four taps can work with a fifth tap and that would be groundwater. Rainwater can be harvested in reservoirs but some amount of it can be recharged into the aquifers to create a groundwater bank to be used as a supplement to piped water. For our inland cities, groundwater would be the fourth tap instead of desalinated water.

The challenge is to push the city away from the first tap and as much as possible to the other taps. This would build self-reliance and sustainability. Each one of the taps must have a defined goal and a step-by-step approach of investment and monitoring to achieve the goal.

The most important challenge, however, is to build an institution like the Public Utility Board or PUB as it is called in Singapore. It is professionally staffed with all the competencies needed, capable of striking partnerships with the best vendors for supply of technology, investing in R and D constantly, making sure they supply water to all households in the city and collect sewage from all households too, understanding demand and setting a tariff to ensure responsible use of water, having the financial muscle for not only Operations and Maintenance but also capital investments with a long term vision.

While in India, we know mostly what is to be done, it is the how is it to be done which becomes the question. We are inadequate in terms of our institutions to be capable of delivering on the ground.

Unless we invest in governance and institution capacity, we will continue to struggle with water shortages and pollution of our lakes and streams. The “four taps” is a good approach; getting the tap-master to perform is water wisdom.

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