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 27,000km2. The area falls under the middle Nigeria climatic belt which is mainly tropical with an average rainfall of about 1250mm. This paper evaluates the hydrogeological potential of the terrain. The methods of investigation include analysis of meteorological, drilling, pumping 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 19m3/hr. Transmissivity values obtained using various methods vary between 1.365 and 393m2/day. Hydrochemical analyses of groundwater samples showed poor mineralization 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.