Application of double lifting method for river water irrigation in the water stressed Barind Tract of northwest Bangladesh

Abstract

Groundwater has become the prime source of drinking and irrigation use in drought-prone Barind Tract (BT) of Bangladesh as the surface water sources are minimal. Continuous groundwater withdrawals for irrigation, drinking, domestics, industries and other uses deplete groundwater levels (GWL). So, the study aims to compute the quantity of river water extracted for irrigation by double lifting and rubber dam irrigation systems of Barind Multipurpose Development Authority (BMDA) in BT area and evaluate their impacts on reducing groundwater exploitation. To carry out the study, bore log lithology, rainfall, GWL, and water irrigation data have been collected from BMDA and field investigation and analyzed the Groundwater depletion due to over-extraction than the potential recharge, lower rainfall than the national average, and thick top clay that limits the natural recharge. Lifted water by the pumps of 11 pontoons placed on the river Padma (Ganges), Mohanonda, and Atrai can reduce 7.08% of groundwater extraction for irrigation in the study area. Groundwater exploitation for Puthia Upazila can be reduced by 10.11% with conserved water upstream of the rubber dam constructed in the Barnai river. Also, a continuous rise in GWL was observed due to storing of river water at a 4 km long section by the rubber dam.