Delhi has potential aquifers to meet the summer water requirement as Delhi Jal Board (DJB) faces the uphill task to meet the demand of 900 Million Gallon Per Day (MGD) of water.
Groundwater experts in Delhi said Yamuna Flood Plain aquifers, brackish water aquifers and aquifers of Dwarka township have the potential to meet water demand during summer season.
The primary source of water in Delhi is Yamuna which travels through Haryana. Out of 900 MGD, 540 MGD comes from Haryana. The second major source of water is upper Ganga Canal, through which it gets 240 MGD daily. During the time of water scarcity situation or water emergency, Delhi can rely on groundwater to supply sufficient amount of th depth to water level occurring at shallow depths of 3 to 7 meters below ground level and can sustain tube wells with yield ranging from 1,400 to 2,800 liters per meter,” said the expert.
“The CGWB has installed 90 tubewells in Yamuna flood plain area and and the DJB is extracting 35 MGD water from it. Also, the water level is occurring at shallow depths of 3 to 7 meters below ground level and can sustain tubewells with yield ranging from 1,400 to 2,800 liters per meter,” said the expert.
And as per the CGWB findings, Yamuna floodplain has exploitation potential of nearly 85 MGD, out of which the CGWB has created groundwater potential of 45 MGD by installing tube wells in the different sectors of the Yamuna floodplain.
Groundwater expert said brackish water at shallow depths can be developed to be utilised for domestic use other than drinking purpose. “CGWB estimated that the development of brackish water aquifers will yield about 80 MGD of water. This brackish water can be used for providing the dual water supply system, where the same pipe lines can be used to supply fresh water as well as brackish water for domestic uses at pre-determined hours of supply.
The brackish water can also be mixed with fresh water to bring the elements under permissible limits as per drinking water standards,” said hydrogeologist.
The aquifers of Dwarka township named Gummenhera depression, Pochanpur depression and Kakraula depression also have the potential to supply fresh water in Delhi .
As per the findings of CGWB, the fresh water supply can be supplemented by marginal fresh quality of water through a battery of tube wells within the township. The fresh groundwater aquifers of East Delhi consisting of two districts occupies about 8.3 per cent of total area of NCT Delhi and about 23 per cent of population resides in East Delhi.
The district is underlain by newer alluvium consisting of predominantly sand mixed with gravel and little amount of silt and clay up to a depth of about 30- 40 meters followed by older alluvium.
“Depth to fresh/saline water interface in this area is about 40 to 45 m bgl. Depth to ground water levels in this area varies from 5 to 8 (meters below ground water) m bgl. CGWB estimated that about 4-5 MGD of fresh water can be extracted from aquifers of east Delhi,” said expert.