Many investigation techniques are commonly employed with the aim of estimating the spatial
distribution of transmissivity and protective capacity of groundwater resources. Unfortunately, the conventional
methods for the determination of hydraulic parameters such as pumping tests, permeameter measurements and
grain size analysis are intrusive and relatively expensive. A non-intrusive and less-expensive geoelectric
investigation involving vertical electrical sounding was carried out in some parts of the campus of Afe Babalola
University, Ado Ekiti, Ekiti State, Nigeria. A total of fifty-nine (59) vertical electrical sounding (VES) data were
acquired using R 50 D.C. resistivity meter within the campus which is underlain by the Precambrian basement
rock of southwestern Nigeria. Following the interpretation of the VES data, maps and 2D-sections were
generated. The geoelectric sections enabled the subsurface to be characterized into five geoelectric layers
namely: Topsoil, clayey/sandy-clay, weathered layer, fractured basement and fresh basement. The assessment
and analysis of the materials above the aquifers showed that longitudinal conductance (S) values ranged from
0.08438 to 0.73449 mhos; thus the area is classified into weak (0.1 – 0.19 mhos), moderate (0.2 – 0.69 mhos)
and good protective capacity (0.7 mhos and above). The major aquifer delineated is the weathered/fractured
basement aquifers. These aquifers are characterized by thick overburden, moderate/good protective capacity,
moderate to relatively high value coefficients of anisotropy and low transverse unit resistance. This suggests
that the materials above the aquifers act as seal, thus protecting the major aquiferous units. However, the
aquifer matrix itself is relatively permeable. Areas with weak protective capacity are therefore vulnerable to
infiltration of polluting fluid