Joseph I. OMADA and Olorunfemi O. OBAYOMI
The exploration, exploitation and evaluation of 28boreholesin Gwarinpa and Kafe areas of Abuja metropolis have been used to assess the groundwater potentials of the basement complex terrain.Of the 28 boreholes developed,three (3) were located on weathered basement with overburden thickness of 24 m, 27.0m and 29.5 m while twenty-five (25) were located on fractured basement intercepted at various depthsranging from 20.0 m to 36.0 m. Among the 28 boreholes developed, 14 (or 50%) had yield ranging from 3.33 m3/hr to 5.0 m3/hr while 8 (or 28.6 %) had yield from 5.1 m3/hr to 6.0 m3/hr whereas 6 (or 21.4 %) had yield between 6.1 m3/hr and 6.70 m3/hr.Wells located on weathered overburden had intermediate yield of 5.0 m3/hr to 5.2 m3/hr while the high yield are from wells located on northerly trending fractures.Groundwater saturation and yield in the area aretherefore due to a combinationof the factors such as the nature of topography, degree of weathering of the basement rocks, thickness of overburden, degree of fracturing and or the interconnectivity of fractures in the basement rocks. The groundwater resource is largeenough for domestic consumption and supplementsthe limited surface water supply to the area.
