Digital recorders to monitor depleting ground water level in Bengal
Digital monitors will help authorities know on a real time basis, the rate of depletion or whether some aquifers are getting recharged during monsoon.
The West Bengal government will soon start installing digital recorders to monitor the level of groundwater in various community blocks, where experts say the water level has depleted alarmingly because of unregulated extraction.
“We would be installing digital recorders in at least 72 community blocks where groundwater has depleted alarmingly. These would help us to know, on a real time basis, the rate of depletion or whether some aquifers are getting recharged during monsoon,” said Suvendu Adhikari, water resources minister.
Senior officials of the department said that these 72 blocks, where the monitors would be installed, are either in the critical or semi-critical categories as far as groundwater level is concerned. There are 42 blocks in the state where the groundwater table has been found to be in the ‘semi-critical’ category and another 30 blocks where the water table is in the ‘critical’ category.
“Till date, groundwater level is monitored manually with monitoring wells at least four times a year. We never get to know how the groundwater level behaves during the intervening periods. But now with the help of digital recorders we will be able to monitor it round the clock on a real time basis. The data would be sent to a central server,” said a senior official of the water resources investigation and development department.
Experts said that this will help find out the trend of how the ground water table is behaving during various seasons and even forecast how it could behave particularly during summer when extraction rate increases.
“Just like we can forecast weather, we would be also able to forecast how the groundwater table would behave if we get to know the trend. If we can forecast how and when the groundwater would deplete, we can restrict the extraction of groundwater in critical and semi-critical areas particularly during summer,” said SP Sinha Roy, former member of the Central Ground Water Board.
This becomes all the more necessary because in Bengal at least 174 blocks have registered depletion of ground water table at the rate of more than 20 cm per year.
“Excess withdrawal of ground water is leading to water depletion beyond recovery at various places. It also causes contamination of water with arsenic, chloride and fluoride among others,” said a senior official of the West Bengal Pollution Control Board who did not want to be identified as he is not authorised to brief the media.