Evaluation of Groundwater Resources of the Middle Niger (Bida) Basin of Nigeria

The Middle Niger Basin lies in the sedimentary terrains of the middle part of Nigeria. It has an area coverage of about 27,000km 2 . The area falls under the middle Nigeria climat ic belt which is mainly tropical with an average rain fall of about 1250mm. This paper evaluates the hydrogeological potential of the terrain. The methods of investigation include analysis of meteorological, drilling, pu mping tests and water quality data. A total of about 50 boreholes located in the area were selected for study. Results of the analyses of the data showed that groundwater occurs both in confined and semi -confined conditions. Depth to water rarely exceeds 50m, though in some few cases may be over 70m. Averagely, well yield varies between 1.08 and 19m 3 /hr. Transmissivity values obtained using various methods vary between 1.365 and 393m 2 /day. Hydrochemical analyses of groundwater samples showed poor mineralizat ion with low TDS (Total Dissolved Solids) rarely over 300mg/ l. The water is fresh, soft and free of chemical pollution and therefore suitable for many purposes.