Five boreholes within the premises of National Water Resources Institute were investigated through a pumping test with the view to ascertaining their yields to meet the water requirement of the growing population of the area.The method used was constant pumping test where constant pumping rate was maintained throughout the duration of pumping and measuring the change in water level (drawdown)with time. The pumping terminated when quasi- steady state condition had been achieved, and immediately, the recovery test commenced and lasted till 90 – 100% static water level was attained.The result showed that the boreholes through the draw down –time graphs have different gradients, implying aquifers of varying Transmissivity (T), Hydraulic permeability(K) and drawdown (s).The T and K values range from 0.5 to 2.5m²/day and 2.1x10^-2 to 15 x 10^-2m/day respectively.The aquifers are overburden and weathered basement, and, theiryields are not a function of depth and specific capacity of boreholes.The pumping periods range between 50mins to 2¹/2hours, an indication of low yielding aquifers, with recovery test trailing equal time interval.The total yields was put at 455.06m³/dayat combined pumping period of 7hours, 50mins, with a total recovery of 87% within a combined time duration of 8hours, 20mins.It was concluded that the yield (if well managed) could sustain about 10,000 population with an average daily water requirement (World Bank estimates) of 0.035m³/day.

Keywords:Groundwater, Drawdown, crystallinebasement, regolith