Union Minister of State for Water Resources, River Development and Ganga Rejuvenation Prof. Sanwar Lal Jat has informed that a paper on ‘Satellite-based estimates of groundwater depletion in India’ was published in August, 2009–Issue, of scientific journal ‘Nature’ by American Scientists from National Aeronautics and Space Administration (NASA) and University of California, United States of America. In that study, an area of about 4.4 lakh sq.km covering the States of Rajasthan, Punjab, Haryana and Delhi, was taken up as a single unit without actual field mapping of ground water levels. The scientists have made an attempt to estimate ground water depletion in north-western India using Terrestrial Water Storage (TWS) change observations from NASA Gravity Recovery and Climate Experiment (GRACE) satellite data for the period from August, 2002 to October, 2008.
The study has indicated that ground water is depleting in the aforementioned four States at a mean rate of 4.0±1.0 cm/year equivalent height of water (17.7±4.5 cubic km/year). On review of the paper by the Central Ground Water Board (CGWB), it was observed that the GRACE mission’s ground water storage studies are satellite based estimates and coarse resolution of GRACE data limits its applicability to study ground water dynamics. CGWB estimations are, however, based on field data and bring out smaller scale variations in the ground water storage pattern over a vast region.
Excessive withdrawal of ground water for various purposes including irrigation, domestic and industrialize are some of the factors responsible for decline in ground water levels and in many areas ground water recharge is reduced due to varied & erratic rainfall pattern as well as change in land use. Central Government has taken several steps to manage ground water level in the Country including: –
• As per Schedule-I of the Mahatma Gandhi National Rural Employment Guarantee Act (MGNREGA), the water conservation and water harvesting structures to augment ground water constitute a special focus area for MGNREGA works.
• During XI Plan, Demonstrative Artificial Recharge Projects were taken up under Central Sector Scheme “Ground Water Management & Regulation”. The scheme on Artificial Recharge project under Ground Water Management & Regulation Scheme has been discontinued during the XII Plan period.
• A conceptual document entitled “Master Plan for Artificial Recharge to Ground Water in India” has been prepared during the year 2013, which envisages construction of different types of Artificial Recharge and Rainwater Harvesting structures in the Country in an area of 9,41,541 sq.km for harnessing surplus monsoon runoff to augment ground water resources.The Master Plan has been circulated to all State Governments for implementation.
• Ministry of Urban Development in its Draft Model Building Bye-Laws (2015) has incorporated a Chapter on Provision of Rain Water Harvesting.
• Central Ground Water Authority (CGWA) constituted under ‘The Environment (Protection) Act, 1986’ for the purpose of regulation and control of ground water development and management has issued advisory to States/ Union Territories and Ministry of Urban Development to take necessary measures for adopting rain water harvesting/ artificial recharge in all the Government buildings. Besides, 30 States/UTs have made rainwater harvesting mandatory by enacting laws / formulating rules & regulations / by including provisions in building bye-laws / through suitable Government Orders etc.
• CGWB has been organizing mass awareness programmes in the Country to promote rain water harvesting and artificial recharge to ground water.