What is de-watering?
De-watering is the removal of water from solid material or soil by wet classification, centrifugation, filtration, or similar solid-liquid separation.
What is Central Groundwater Board (CGWB)?
CGWB is a subordinate office of the Ministry of Water Resources, Government of India. It is the National Apex Agency entrusted with the responsibilities of providing scientific inputs for management, exploration, monitoring, assessment, augmentation and regulation of ground water resources of the country.
It was established in 1970 by renaming the Exploratory Tube wells Organization under the Ministry of Agriculture, Government of India.
It was merged with the Ground Water Wing of the Geological Survey of India during 1972.
What has CGWB report said?
After analysing Delhi's groundwater table data in past one decade the board has concluded that the national capital's overall groundwater level is depleting by a maximum of 1.44 metres per year because of increased extraction.
As per a Hindustan Times report, the board on September 1 had asked the 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.
"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.
The board in its report has further said that the metro has neither taken enough measures to conserve groundwater nor has it done a proper study of water disposal plans. CGWB has also accused the DMRC of not taking proper permission from the Delhi Jal Board (DJB) before extracting water.
What is DMRC saying?
According to the DMRC spokesperson they always follow water conservation norms and the metro department will continue doing that in future as well.
Historical Red Fort Baoli drying up
The Mughal-era Red Fort Baoli, which has remained water-fed for centuries, has suddenly started depleting drastically over the last few weeks and has almost diminished. When the alarmed Archaeological Survey of India (ASI) officers probed this sudden loss of water they came to a conclusion that the it was digging at a metro construction site, nearby the Red Fort, which led to the sudden loss of water from the historical baoli.
"The water level started going down when Delhi Metro was doing tunneling work. They cut into the water source at some point because there is no other reason why the levels would suddenly dip," ASI officials were quoted by TOI as saying.
NGT's notice to Delhi Metro
Earlier last year, National Green Tribunal (NGT) had served notice to the DMRC for failing to harvest rainwater at its stations and depots.