The Delhi Metro is carrying out large-scale, illegal and unscientific de-watering which will push the already depleting groundwater table further down, the Central Groundwater Board (CGWB) has said.
De-watering is the removal of water from solid material or soil by wet classification, centrifugation, filtration, or similar solid-liquid separation.
An analysis of data from the last 10 years shows the overall groundwater level is going down by a maximum of 1.44 metres per year because of increased extraction. In Delhi, the demand-supply deficit is about 300 million gallons per day, forcing people to use illegal bore wells and rely on the tanker mafia.The apex government body on groundwater has, on September 1, asked the Delhi Metro Rail Corporation (DMRC) to get a detailed groundwater impact study done through a reputed consultant and submit a report with details on quality and quantity of water being drawn, site-wise utilisation, impact on water table and recharge plans.
The CGWB has in a letter, accessed by HT, told the DMRC that though extraction of groundwater is necessary to build underground stations but this water has to be used for simultaneous recharge. “Heavy de-watering is going to impact groundwater situation adversely. Delhi is notified for falling water table. DMRC should have undertaken comprehensive impact studies as well as prior clearance before starting de-watering,” the letter said.
“We have always tried to follow water conservation norms. We shall continue to make the same efforts in future as well,” a DMRC spokesperson said.
The board asked for immediate compliance of its recommendations after inspecting Kashmere Gate and Shalimar Bagh Metro construction sites. The inspection found continuous de-watering to build underground stations. “The groundwater conservation measures do not appear sufficient. There is no scientific study for a water disposal plan. DMRC has not taken proper permission from Delhi Jal Board,” the CGWB had said.
In November 2013, HT had first reported that the DMRC has in reply to a right to information application admitted it was carrying out de-watering while using bore wells without approval. The next month, the matter was raised in Parliament, followed by an inspection by the CGWB.
The National Green Tribunal has also pulled up the Delhi Metro, which has an operational network of 192.5 kilometres, for having failed to ensure rainwater harvesting systems at many of its stations, resulting in a loss of millions of litres of water every monsoon.