People working in the water sector call it the ‘water footprint’ i.e., the distance water has to travel before it reaches taps in the city and the distance it travels before it is treated or absorbed by nature. As India’s urban areas grow the demand for water grows. As the density and the verticality of the cities grow and as the economy grows the demand for water too grows. The demand on sources overwhelms current ones and generally the distance to the next source has to increase by tens of kilometres.
Consider the case of Bangalore. As far back as 1892 the city had to look at Hesaraghatta reservoir on the Arkavathy about 20 km away; then depend on the T.G. Halli reservoir in 1933 about 30 km away; and finally settled for the Cauvery in 1972 about 95 km. away. So far so good. But a recently appointed committee has recommended considering sources as far away as the west flowing rivers about 230 km away and the Sharavathi river about 300 km away.
Consider Chennai city which draws water from the Cauvery through the Veeranam reservoir about 220 km away as well as the Krishna river more than 300 km away. Delhi gets its water from as far away as 300 km. and Mumbai from a distance of 150 km. Even a small town like Doddaballapur close to Bangalore has to move to a reservoir about 20 km away for its water need and the reservoir is on a river which is in a different river basin altogether.
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This means that the energy requirement for transporting water now increases considerably in an energy-short nation. It also means that the capital cost for the new water schemes would run into hundreds of crores that would make the landed cost of water in the city expensive.
It also means that cities have to seriously look at reducing their water footprint.
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* Reduce, reuse, recycle and rainwater harvest would be the ‘4 R’ mantra which cities will need to encourage through policy. Starting from the smallest unit of consumption this mantra will need to be applied.
* Reduction will come through many considerations such as better water-efficient appliances and also through pricing which will dissuade large per capita consumption.
* Reuse will come through initially small scale grey water being used for gardening and such.
* Recycle will be through sewage treatment and wastewater recycling plants at household level to city level.
* Rainwater harvesting can also be done from an individual building level to city levels in lakes.
Policies which push for better management of water as a local resource will not only help augment supply but also reduce the cost of capital required for water. Increased participation of the city and citizens will be needed, and that is water wisdom.
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