Technical Assessment of Small-Scale Groundwater Development for Rural Irrigation in Kogi State

This study conducts a technical assessment of small-scale groundwater development potential for rural irrigation in Kogi State, North Central Nigeria. Groundwater is an important but underexploited irrigation water source in Kogi State, where surface water availability is seasonal and declining. The geology of the Niger-Benue confluence area, which underlies much of Kogi State, is characterised by alluvial aquifers and weathered basement rock with moderate groundwater potential. This study integrates hydrogeological data analysis, borehole yield assessment, water quality testing, and hydraulic pump sizing for irrigation applications. Hydrogeological assessment uses data from the Lower Niger River Basin Development Authority borehole database, supplemented by electrical resistivity surveys at 15 sites in Lokoja, Okene, and Idah local government areas. Groundwater quality parameters including nitrate, fluoride, iron, and total dissolved solids are measured. Pump sizing calculations determine irrigation water supply potential per borehole for representative farm sizes. Findings reveal that alluvial aquifers along the Niger and Benue Rivers yield 2.5 to 8 litres per second per borehole, sufficient to irrigate 0.5 to 2 hectares depending on crop and season. Groundwater quality is generally suitable for irrigation with elevated iron concentrations requiring simple aeration treatment in some locations. Drilling cost averages 750,000 naira per borehole. The study concludes that groundwater development offers significant rural irrigation expansion potential in Kogi State. It recommends state-subsidised borehole drilling for smallholder irrigation groups.

Keywords: groundwater development, rural irrigation, Kogi State, hydrogeology, borehole yield.