After a good rainy season, it’s the right time to assess the situation with water expert S. Vishwanath. By Ranjani Govind
Water experts time and again make it clear that human negligence is the main reason for water crisis in most cities. Almost 30 per cent of the groundwater in the country has slipped into the over-exploited categories they say, even as such trends will only witness more water bodies disappearing, mainly in urban sprawls.
Add to this the rapid and disorganised real estate growth, the alarming concretisation of roads and public areas, administrative apathy of officials and irresponsible attitude of citizens, and we are into a larger mess.
With such a background and unbridled real estate growth, what is the water status in Bengaluru? The Composite Water Management Index report released by Niti Aayog in 2018 that says 21 major cities, including Bengaluru, Chennai, Delhi, and Hyderabad, will soon reach the zero ground water level. Ask water conservation expert S. Vishwanath how, in this background, we can look at sustenance when the ecosystem in the city is disturbed, and he says, “According to the Composite Water Management Index ,Bengaluru should have run out of groundwater this year. The Groundwater Authority reports a rise in groundwater tables. It is clear that groundwater recharge methods are working to a large extent. More recharge needs to be done.”
A Legislature Committee constituted to study the encroachment of lakes in and around Bengaluru sometime ago said approximately out of 60,000 acres of lake area, nearly 10,800 acres have been encroached upon. The last five decades saw Bengaluru lose more than 60 per cent of its water bodies, and the last two decades have seen the water table sink to 70 metres below ground, i.e., a seven-fold fall, according to Centre for Science and Environment (CSE).
While the United Nations and Niti Ayog report that 40 per cent of India’s population will not have access to clean drinking water by 2030, the crisis gets precipitated with continued large-scale migration from villages as sectors such as agriculture, handicrafts, weaving and fishery are drying up. Will the city need better physical infrastructure for correcting distribution losses? Mr. Vishwanath says distribution losses have been substantially reduced by the BWSSB. “With district metering (to individually monitor the water supplied and consumed) and thanks to L&T contracted project, things have worked well. It needs to be reduced further. This year’s copious rain and the systems are in place for a better scene.”
And how much water does Bengaluru require for its 1.2 crore population with the trend of lakes drying up and increased concretisation? “At 100 litres per capita per day (LPCD) Bengaluru needs 1,200 million litres per day. We are already getting 1450 MLD from the Cauvery plus 600 MLD from groundwater. Distribution is the key,” says Mr. Vishwanath who is also a civil engineer and urban planner by qualification. “Addressing groundwater is enough if all people harvest rainwater and recharge. One has to go along the demand management,” he adds.
There should be no overall scarcity in summer, says Mr. Vishwanath who has had hands-on experience working with HUDCO before he dedicated himself to solving water issues facing urban and rural communities. “The dams that are supplying water to Bengaluru are full. Groundwater is at good levels. Pockets of distribution inefficiency will see some shortages, that’s all.”
Touching on problems of gated communities in the past where RWH has had its own set of ineffective results due to negligence, he says it’s high time all apartments and gated communities understand RWH in its entirety. “Recharged water needs to be reused and the groundwater level kept down. Such basic lack of water literacy skills with communities is a problem. In no way will the water collected underground affect the foundations, and one need not go to that extent of worry.”
And finally touching on better watershed management that people often refer to in the social media, Mr. Vishwanath says “Urban watershed management is a complex subject. The lakes which are being rejuvenated need to have a connection with the catchment area. By making sure that the catchment area has no uncollected sewage, and by designing for rainwater harvesting systems in the watershed much improvement can occur.”