YESA borehole is termed dry when the water level goes below the pump intake level. This is dependent on:-
Groundwater abstraction rate
Rate of recharge to the underground water reservoir
Over abstraction from a fair potential aquifer can cause water levels to drop or even deplete the reservoir especially where recharge is poor. Perched aquifers too aren’t sustaining.
Boreholes that tap water from the upper (temporary) water level zone are likely to run dry in drought seasons since the water table varies with yearly seasons whereby the level drops to the lower (permanent) water table zone.
It is therefore important to note that it is very essential to do a borehole professionally with all understanding for economical purposes of a successful borehole construction, development and maintenance.
Borehole drilling is done in independent phases:
Hydrogeological Survey and consequent WRA and NEMA License
Actual Drilling exercise – Open hole, Casing, Gravel Packing and capping
Borehole Equipping – Electrical / Solar Pump installation
Piping works and Steel tanks erection for water storage
The main cost of drilling borehole is largely dependent upon the depth and amount of casing that the borehole will require. The type of rock (Geology) that we have to drill through does have some influence as well as the actual ground conditions. Many people think that the easiest way to drill a borehole is through the soft and loose geologies. However, this is not the case, in fact, the opposite is true. This is made more difficult if the hole is collapsing due to the ground being loose and unstable. We use many different methods to prevent this phenomenon from occurring, including use of drilling fluids and additives as well as the installation of temporary steel casing. All these factors add up in the overall cost of a borehole.