Hi Hussein. To answer your ...

Hi Hussein. To answer your question directly, Geophysics helps you to delineate the depth to the water table in the area. Mostly resistivity is measured to map to the depth to the water table, however, the result should be tied with other existing boreholes or Geological features as it is not 100% accurate. Saying that, I do not have the detailed Geological census of the area but from my experience the issue that you are facing is the drop down of the water level in side the borehole and generally the whole area. Hence, I would recommend you to conduct the Geophysical studies during dry seasons as this is the period where the water table recedes the farthest. You might want to add a depth safety factor to your studies depending on the recharge which range from 0.25 to 0.75 and to start drilling at any other time that you see fit. I hope that answers the question, cheers Tesfaye