The most common device used by men for tapping groundwater is the wells. This a vertical opening or shaft excavated into the zone of saturation. They serves as reservoirs into which ground water moves and form which it can be pumped to the surface. The amount of water that they will yield depends chiefly on
v The permeability of the aquifer
v Thickness of the aquifer
v Diameter of the well
Types Of Wells
Depending upon the method construction they may be classified into the following groups:-
Dug type are excavated by means of picks and shovels and their diameter is usually more than one meter. These seldom exceed a depth of 20 meters, as the depth of such type of well is not more so such kinds are mostly used in low standard areas.
The well in the unconsolidated material may be constructed by driving a pipe at the end of which there is a driven point. The diameter of such well seldom exceeds 7.0 centimeters.
The bored type well are constructed in the unconsolidated materials by means of hand or power augers.
These wells are excavated in the loose earth material by the force of the jet of water which is produced by pumping water through hollow drill rods.
v. Drilled wells
The water form consolidated aquifers is extracted by drilling deep. These wells are generally constructed by hydraulic rotary drill method. The drilled wells may attain a depth of 70 meters or more.