3.5 L buildings in deep water?
Initial findings of a study organised by the civic body suggests depleting groundwater levels in Mumbai pose a risk to its numerous skyscrapers
While the city’s skyline has been recurrently breaking new ground, the ground realities have been steadily changing for the worse. And the 3.5 lakh buildings in the city seem to be in a precarious position. The primary point of concern is the fast-depleting groundwater level. The civic body has appointed a study group comprising members of Pune-based Groundwater Surveys and Development Agency (GSDA) to assess the state of affairs. GSDA has chosen two civic wards, M-east (Chembur) and P-south (Goregaon) as part of a pilot project that commenced four months ago.
On Friday, the civic standing committee gave a green signal for the survey and sanctioned a proposal of Rs 29 lakh as cost of the project. “Many a times we face problems while repairing underground storm water drains or water mains during high tide. As we go 15-20 feet deep, seawater rushes in and disrupts our work. Then we wait until it’s time for low tide,” said a senior civic official.
Time to stop, think
In 2009, the year when the city received about 75 per cent of its quota of average monsoon rainfall, there was severe water scarcity. A 10-percent cut in supply of water was practised throughout for a whole year. The city already has over 7,000 borewells, of which 2,000 were dug in the last six years. BMC’s hydraulic department had to earlier withdraw restrictions over digging borewells because of water scarcity. The corporation reenacted the curbs in 2011 after observing decline in the groundwater table.
After their preliminary analysis, GSDA experts have said that dissipation of groundwater may lead to seawater seeping into the soil, endangering buildings. “Diminishing groundwater table would definitely be damaging for the foundations of the structures and there’s need to increase the sweet water table to the safest level,” said KM Nagargoje, director of GSDA.
“We have started work on compiling data and history of the city, like old maps and other key information. It will take at least two years to complete a comprehensive study and find out statistics about the exact level of groundwater table,” said Suresh Khandale, additional director of GSDA.
The pilot project included Chembur as it has a creek nearby while Goregaon was elected because of it being one of the fastest developing parts of the city. “We have taken a bird’s-eye view of the city from the 35th storey of a building in the western suburbs before initiating our work,” Khandale added. Rahul Shewale, chairman of the civic standing committee said, “This is a good initiative by BMC and we will surely plan how to boost the groundwater table of the city.”
Number of borewells in the city that have caused exploitation of the water table