The Yamuna is expected to go green by the time the Commonwealth Games come to Delhi in three years. For now, it is brimful with a toxic drainage discernible on Google Earth.
The capital accounts for 80 per cent of the Yamuna’s pollution load. Other Indian cities don’t do better by their water bodies either. These are down from 530 to 150 in Hyderabad, Varanasi’s sewage causes 95 per cent of its Gangetic pollution and builtups have reduced Mumbai’s Mithi river by half. This systemic destruction of natural drainage systems lays cities low with floods in the monsson and leaves them parched during the drier seasons.
Reviving an ancient legacy
In drought-prone Gujarat, the people of Dwarka still have plenty to drink because the centuries old water-harvesting tankas are still going strong there. According to the CSE, 60 per cent of even the new houses are equipped with such structures and devoting money for the construction of tankas is considered sacred work to this day. In most of the country, however, traditional systems have fallen into disuse or disrepair. For instance, Baiji-ka-talab in Jodhpur and the Mehrauli baoli in Delhi often remain dry even in rainy seasons.
Overall,according to Ramaswamy Sakthivadivel of the International Water Management Institute, of the up to 1,000 mm of rainfall that falls onto the Indo-Gangetic plain annually, only 200 mm percolates to replenish our aquifer. But, as it does not cost much for communities to channel rainwater into the ground, wiser city planners are sensibly reembracing the conservation mantra.
Chennai has made rainwater harvesting mandatory, Indore gives a tax rebate on the same and Bangalore is set to follow in Chennai’s footsteps. In Delhi, according to the Society for Conservation of Nature, rain water harvesting and recycling could eliminate the demand-supply gap by 2021.
Waste not, want not Even wastewater can become an asset rather than a problem. As a 2006 Global Water Partnership paper by Judith A. Rees illustrates, planned use of urban wastewater for peri-urban irrigation can yield cheaper vegetables for the city dwellers and provide a reliable water supply for agricultural communities. Properly treated, it can also improve the quality of India’s rivers.
Kolkata has arrested the flow of sewage into the Hooghly by equipping primary underground sewers with treatment plants. In Hyderabad, the installation of such plants in industrial areas has substantially reduced the toxic inflow into the Hussainsagar Lake. Such measures enhance the ability of water bodies to withstand the monsoon and also augment percolation into the groundwater. They are profitable ventures even in monetary terms, with a 2004 WHO study demonstrating that a cross-sectoral outlay on water and sanitation generates returns ranging from $5-11 on every dollar.
The IPCC forecast for us is full of droughts and torrential rains. By making every drop of our storm and wastewaters count, we can be better prepared for the tempestuous times to come.