The IISc professor who famously ‘saw the future of Bengaluru’ a decade ago, speaks to Down To Earth about where the city went wrong and how it can right itself
Professor T V Ramachandra from the Indian institute of Science, Bengaluru
There was a time when Bengaluru was known for its green cover, perennially chilly weather, and landscape, which was dotted with over 280 lakes and waterbodies and two rivers — Vrishabhavati and Arkavathi — tributaries of the Cauvery river.
Vrishabhavathi, which flows through the southern part of Bengaluru, is now turned into the city’s biggest effluvium drain known as Kengeri Mori (Kengeri sewage drain). The city’s 262 lakes in 1961 dwindled to just 81 in 2020, of which only 33 are ‘living’.
The man who foresaw all this destruction as an impending disaster for the city of Bengaluru in terms of water scarcity is T V Ramachandra, Head of the Centre for Ecological Studies at the prestigious Indian Institute of Science (IISc).
Despite his cautions and warnings from time to time, which the city did not heed, it is now on the way to facing ‘Day Zero’ just like Cape Town in South Africa did in 2018.
Prof TVR, as he is fondly known not just inside the IISc campus but all over the country, is one of India’s top scientists in the study of hydrology and conservation of water bodies. His spectrum of studies includes energy, wetlands, soil and water pollution, GIS and remote sensing and environmental education.
He had warned that Bengaluru would face severe water shortage during a conference on lakes in 2016. Ramachandra had presented a paper at the event held in Moodbidri, coastal Karnataka.
TV Ramachandra spoke to Down To Earth in an exclusive interview. Here are edited excerpts from the interview:
Down To Earth (DTE): When you came out with the study on Bengaluru, what sort of response did you get from official quarters?
TV Ramachandra (TVR): Indifference. Had the mitigation measures been implemented, the region would not have faced such a serious situation.
DTE: You had predicted the current scenario because of the destruction of Bengaluru’s lakes. Do you feel vindicated in a way, unfortunate though it is?
TVR: There has been a 1,055 per cent increase in paved surfaces (buildings, etc.), with a substantial reduction in porous surfaces (88 per cent reduction in green cover and 79 per cent reduction in waterbodies). These are the prime reasons for the current situation. The city landscape of 740 sq km had 68 per cent green cover. Today, we have less than three per cent green cover, with 85 per cent paved surfaces.
DTE: Will Day Zero happen in Bengaluru like Cape Town?
TVR: With continued fragmented governance (too many para-state agencies) and lack of coordination, the city witnessed unplanned and irresponsible urbanisation, resulting in the loss of liveable areas. We are consequently inching closer to Day Zero.
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The city administrators completely ignored the welfare of citizens, as is evident from the abuse of natural spaces. Our study shows that the groundwater table was less than 100 feet when a ward had a waterbody.
After removal/conversion, the groundwater table dipped to 600 feet in five years. Today (after 23 years), residents have gone deeper to 1,900 feet and there is no water. A similar grim situation in most parts of the city means immediate corrective measures are the need of the hour.
DTE: What should the authorities do, given the monsoon is still far away?
TVR:The city receives annual rainfall of 700-850 millimetres, which means we have 15 Thousand Million Cubic Feet (TMC) of rainwater. The city requires 18 TMC of water, which means rainwater would suffice 70 per cent of water demand.
The best option is to harvest rainwater in individual households (rooftop rainwater harvesting) and in rejuvenated lakes. Retaining water in the rejuvenated lakes would aid in groundwater recharge while enhancing the water storage capacity.
Wastewater treatment is a viable option. Economical, nature-based solutions (integrating constructed wetlands and algal ponds with secondary treatment plants as in Jakkur lake) for wastewater treatment are the best option.
This model provides tertiary treated water. We have monitored Jakkur lake for the past twelve years. Some 85 to 90 per cent nutrients and chemical ions have been removed.
Treatment of 18 TMC of wastewater through this method would provide 16 TMC of tertiary treated water. This means the city would have 31 TMC of water (15 TMC with rainwater harvesting and 16 TMC with wastewater treatment).
Realistic options in the current crisis situation are: (i) Advocating and ensuring water conservation at all levels (ii) Ensuring tertiary treatment as the city has wastewater treatment capability and filling select dry lakes to facilitate groundwater recharge (iii) Make bureaucrats accountable for the dereliction of the prudent management of natural resources and pushing irresponsible urbanisation (for their short term gains) (iv) The government should constitute think tanks (with experienced experts and not industrialists).
DTE: Will big cities in India have to get their water from far away in the future?
TVR: Post globalisation, with the push to unrealistic market forces, most cities in India have experienced rapid unplanned urbanisation and have transformed to unliveable cities with serious water crises, acute groundwater scarcity, lower oxygen levels (with the decline of vegetation cover), enhanced land surface temperature (heat islands) and an increase of vector-borne diseases.
Changes in the climate with altered climatic regimes (changes in temperature, rainfall patterns, instances of high-intensity rainfall leading to flooding, etc.) necessitate planned interventions with prudent management of natural resources to sustain clean and adequate water for our next generation.
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