A hydro geological mapping of the Federal Surveys of Nigeria, Kabo Sheet 80 NW, on scale 1:50,000 were made with areal coverage of 729Km2 on the Crystalline Basement Complex, and the hydrogeoogical maps produced are maps of depth to the water table and maps of configuration peak of dry season and wet season, for 2 consecutive years. Hydrogeological cross-section, and hydraulic gradient was also determined as 0.015m. These configuration maps show depth of water and direction of groundwater flow and the constructed hydro geological maps of water tables show a correspondence between the water table contours and topographical contours; as well as revealed the effluent nature of the river system in the study area. Also hydrograph analysis of 2 (Km) gauging station at River Challawa was conducted for only 2 hydro years 1971/72, thus a total runoff average of 216,240,192m3/a and mean base flow of 114,455m3/a, and surface runoff mean of 159, 228,113m3/a, also mean base flow coefficient of base 0.0182, and mean coefficient of surface runoff 0.062m were determined for the area.
Key words: Hydro geological maps, Configurations maps, Hydro years, Base flow, Coefficient of base flow and Hydraulic gradient.