Evaluation of Yield of Wells in Ado-Ekiti, Nigeria

Abstract

Pumping tests were conducted on twenty selected boreholes and five hand-dug wells cut across Ado Ekiti Metropolitan (AEM) area, with the view to ascertain yield of the wells. Constant rate pumping test and recovery method test were carried out. It was revealled that discharge is directly proportional to the yield of the boreholes and hand-dug wells at a constant drawdown, hence the discharge rate  gives the yield of each of the selected boreholes. The borehole depth ranges between 40 – 120 m while hand-dug well ranges between 3 – 15m. Borehole yield in the AEM area ranged between 0.267 l/s and 2.0 l/s. The yield was not totally dependent on the depths, but also on such parameters as porosity and permeability.  The potential of groundwater in AEM as it relates to quantity is high as all wells yielded water. The average water consumption in litres per person per day for high class income earners was estimated at 196 l/d, while that of low class income earners was 119 l/d. Most residence in AEM depend on ground water for domestic water demand. Possible improvement strategies to groundwater exploitation were highlighted. These improvement strategies and remedies are predrilling geophysical survey before siting of boreholes, monitoring groundwater exploration to avert depletion of groundwater potential zones encouraging sufficient recharge period and conducting regular laboratory tests.

Keywords: yield, boreholes, hand-dug wells, recharge, Ado Ekiti.