General Groundwater is the most important source of water supply in Bangladesh. Groundwater in Bangladesh, except in some places, is available at a shallow depth. Groundwater levels are at or near ground level during the period August-October and lowest in April-May. There are several areas of Bangladesh where groundwater withdrawals are causing a large decline in groundwater levels during dry seasons. Due to the over-exploitation of groundwater for irrigation purposes, the water level declines, rendering thousands of suction modes of shallow tube wells and deep-set hand pump tube wells inoperable.
In that places deep tubewell may be introduced. Barind tract area is one of those where deep tubewell is better suited than shallow tubewell. There is presently more than 6850 number of deep tubewells in the Barind project of which few hundreds are of modified types. The design of deep tubewells mainly involves the selection of length, diameter, and slot opening of the screen and design of the shroud materials, on the basis of the available aquifer characteristics. It is important that the entire tubewell is installed straight and vertically. Development of the tubewell is done by pumping the well, usually at 1. times the rated capacity; to wash out the fines in the aquifer and clay or other materials introduced during boring. In case of hand pump tubewells, continuous pumping is done to achieve maximum discharge from the tubewell.