GEOELECTRIC SOUNDING FOR GROUNDWATER POTENTIAL APPRAISAL AROUND THE NORTHEASTERN - SOUTHWESTERN PARTS OF THE FEDERAL POLYTECHNIC ADO – EKITI CAMPUS, SOUTHWESTERN NIGERIA

The electrical resistivity method of geophysical prospecting was used to determine the factors responsible for the non-availability of adequate productive boreholes and the reason for the failure of a particular existing borehole around the Northeastern – Southwestern part of the Federal Polytechnic Ado- Ekiti. The vertical electrical sounding (VES) technique involving the Schlumberger electrode array was adopted and a total of twenty-five (25) VES stations were occupied. The data collected were interpreted quantitatively by partial curve matching and computer iteration. The interpretation results revealed the presence of four lithologic units which include the lateritic topsoil/laterite, the highly weathered/clayey layer, the partly weathered/fractured basement and the non-fissured/fresh bedrock. Contour maps were prepared from the highly weathered layer, partly weathered/fractured basement and overburden thicknesses for appraisal. These maps were carefully examined and synthesized to characterize the study area into good and poor groundwater prospective segments. The highly weathered layer and partly weathered/fractured basement constitutes the main aquifer units, but that of the highly weathered layer is dominant. The two existing productive boreholes were observed to be located within the zones identified as good groundwater potential zones, while the failed borehole exists on a poor groundwater potential zone. The study area has generally limited groundwater potential, and this may be responsible for the non-availability of adequate productive boreholes. This study therefore is significant in that it will assist the institution’s authorities in deciding which part of the study area is to be focused for the purpose of siting groundwater boreholes or any ancilliary water facilities in that regards in the future times so as to forestall recurrence of failures as has been witnessed in the past, while the reading public will find it as a useful reference in proferring solutions in the areas of general basement complex groundwater location, and more particularly where the geology is similar to that of the study area