Exploration of Artificial Groundwater Recharge in Coastal West Bengal

Abstract

Fresh water scarcity is the main problem for growing crops in the coastal West Bengal beyond the rainy season. To alleviate the water scarcity during the non-monsoon period, augmentation of capacity of ground water through artificial recharge during the rainy season was experimented at ICAR-CSSRI, RRS, Canning Town farm. A recharge tube well of 12.7 cm diameter and 40.5 m depth was installed in the year 2011. As the water table came up very close to the surface (< 1 m bgl) during the rainy season, an experiment was carried out for lowering the water table by pumping during summer and artificial recharge of runoff water during the rainy season. For pumping out the ground water, 1 HP electrical pump with discharge of 0.64 lps was used. In spite of 30 days (6 hours per day) of pumping in the summer season, the pumping water level was not lowered below 6 m depth. There was depletion of the water table due to pumping till 27^th  week from January, 2012. Later the water table moved up due to recharge in the monsoon period. The rising of water table near to the surface was similar to previous year when tube well was installed during July/August, 2011 and there was no artificial recharge. Therefore, the present situations are not conducive for artificial recharge in the Canning area. However, if at any location the water table in post monsoon season depletes regularly beyond 3m bgl, there artificial recharge may be done.