CENTRAL GROUND WATER BOARD
Hydrogeological Surveys
Central Ground Water Board carries out regional hydrogeological studies which provide information on ground water occurrence in different terrains and are essential for future planning of ground water development and management. First level (Systematic) surveys on 1:50,000 scale has been completed for the entire country by March, 1991.This has generated basic information on various hydrogeological parameters. Ground water being replenishable and dynamic in nature, it becomes essential to conduct periodic hydrogeological studies (Reappraisal hydrogeological surveys) to assess the qualitative and quantitative changes in the ground water regime in time and space. Approximately 2 lakh sq.km. area in different parts of the country is covered under periodic studies every year. These studies help in reassessing changes in ground water scenario consequent to various development activities.
Photogeological and remote sensing data is extensively used for hydrogeological purpose viz. source finding to demarcate the area and sites suitable for ground water development. Areas remaining hitherto inaccessible have also been surveyed and these techniques have proved very useful in understanding ground water scenario on regional scale. Advanced surface geophysical methods are used as source finding technique. In hard rock terrains, this technique has proved indispensable to decipher sub-surface saturated fractures or situations suitable for ground water occurrence.
CGWB renders assistance to various urban, defence and public sector establishments to solve their immediate water supply problems by selecting suitable sites for construction of ground water abstraction structures. The Board has carried out detailed surveys in Lakshwadeep and Andaman and Nicobar Islands to delineate shallow fresh ground water lenses and deep ground water zones in an otherwise saline water environment. Central Ground Water Board has also helped the Rajiv Gandhi National Drinking Water Mission in identifying suitable ground water sources for drinking water supply.