Evaluation of groundwater potential in Buna, Wajir District

Abstract

Geophysical and hydrogeological investigations were carried out to evaluate the groundwater potentials in Buna, Wajir district, in order to establish areas of ample stock of groundwater that could be developed as a source for a central water supply system. Results show that the hydrogeological system in the study area consists of only one aquifer horizon. This aquifer is confined and consists of the weathered upper portion of the basement system underlying the area. The aquifer has an average thickness of 10 meters and is exploited through hand-dug wells that are basis of mini water supplies. The average value of transmissivity (T) and hydraulic conductivity are 3.25 x 10 -5 m2 S-I, and 3.25 x 10 -6 m S-I, respectively. These values of transmissivity and permeability indicate considerably low productivity of the aquifer. The rocks in the area however exhibit both folding and faulting which enhance the aquifer productivity. Consequently, the areas marked by the wells no. 5,10,12 and borehole C3595 close to a NW-SE and N-S fault lines; and far to the North down a trough or basin marked by wells no. 13,14 and 17 have the best chance of striking a fairly yielding wells and boreholes. Chemical quality determination shows that-the groundwater is generally hard, but suitable for use in domestic and livestock water supply.