State Water Board Research Articles

An analysis of existing borehole data from the Bauchi State Water Board (BSWB) and Bauchi State Agricultural Development Project (BSADP) was carried out with the aim of defining areas with high potentials for groundwater in the western part of Bauchi. It was also aimed at determining any relationship between rock type and yield of aquifer within the area, as the existence of such a relationship will go along way in minimizing the problems of exploration for suitable aquifers in the area. The methodology involved analyzing all pumping test data available for the area and determining the properties of the aquifers such as yield, specific capacity, transmissivity and hydraulic conductivity. The results show that yields of aquifers in the area range from as low as 1.8 litres per minute (lpm) to over 400 lpm with and average of 50 lpm. Specific capacities range from 0.4 – 100 lpm/m with over 63 percent of the area having specific capacities between 0.5 – 10 lpm/m. Transmissivities of the aquifers range from 0.8 – 5.0 x 10 –4 m 2 /s with over 73 percent of the area having transmissivities ranging between 0.8 – 1.0 x 10 -4 ; and only 12 percent of the area having transmissivities above 4.0 x 10 -4 m 2 /s. Hydraulic conductivities in the area range generally from about 9.88 x 10 -7 to 4.77 x 10-5 m/s, with over 73 percent of the area having hydraulic conductivities of less than 8 x 10 -6 and only about 7 percent of the area having hydraulic conductivities of more than 5.0 x 10 -5 m/s. An attempt to correlate the above results with the rock types in the area showed that the fractured coarse grained granites hold better promise for groundwater because it gives higher yield and higher specific capacity than the other rock types. The granite gneiss is next in terms of yield and specific capacity. All the other rock types, Biotite granite gneiss, Hornblende granite and Undifferentiated gneisses, have very little promise for groundwater. KEY WORDS: Groundwater, Pumping test data, Aquifers, Transmissivities, conductivities. Global Journal of Geological Sciences Vol.3(1) 2005: 39-44