KOLKATA, 17 AUG: A casual approach to a serious civic issue, the rampant misuse of groundwater, might lead to massive subsidence in the city in the near future, engineers and geologists spoken to by The Statesman have said. Though the cave-in on Council House Street today was due to the collapse of the underground brick sewer, engineers of Kolkata Municipal Corporation and the State Water Investigation Directorate said the groundwater table in the city has been so badly affected that if steps are not taken now, there will be massive subsidence in the city. Geologists said the groundwater level in some areas in the city has fallen below six metres. These include Park Street, Sarat Bose Road and its neighbourhood, Southern Avenue and surrounding localities, Gariahat Road, and Jadavpur and its adjoining areas. These areas, referred to in civic authority parlance as "south of Park Street", are where hundreds of highrise apartments have come up in the past three decades. Nearly all these buildings have or are in the process of installing deep tube-wells to lift groundwater. But Kolkata is not the only major urban conglomeration ~ to call it a "metro" would be very disingenuous ~ in Bengal where subsidence is a major concern. Rampant illegal mining has led to subsidence in vast areas surrounding the smaller town of Asansol too. To cope with the situation, the state government has set up committees in the city and districts to stop indiscriminate sinking of deep tube-wells. Permission from the committees ~ headed by the municipal commissioner in the city and district magistrates in the districts ~ is needed to sink deep tube-wells, but that's a rule observed more in the breach. A senior civic official, disgusted at the collapse of political will to tackle real civic issues, said that the committee in the city exists only on paper. The state government has allowed construction of buildings of unlimited heights if the width of the road on which it is located is more than 15 metres. All these buildings have deep tube-wells. On Panditiya Road in the heart of south Kolkata, for example, a massive 18-storeyed residential complex backed by a city developer is well on its way to completion and applications for nearly 30 other buildings of between 12 and 15 storeys are pending before the municipal building committee. All these buildings will be lifting ground-water but both the state government and the KMC are silent on the issue. Architects and builders said that fearing subsidence in almost all G+4 buildings and above, builders are resorting to piling and this has led to a sharp spike in the cost of construction, which in turn is being passed on to consumers looking to purchase residential units thereby heating up the property market. A prominent developer, himself an architect, confirmed this trend and said immediate steps need to be taken to replenish ground water and augment the supply of drinking water in the city. Rainwater harvesting is being tried as it reduces the pressure on the use of drinking water, but not everybody is game for it, he added.