Groundwater potential for irrigation in the Nabogo basin, Northern Region of Ghana

Abstract

The inhabitants of Nabogo basin in the Northern region of Ghana rely on surface water sources for their daily water needs. These sources are, however, unreliable throughout the year due to semi-arid conditions of the area, leading to water scarcity in the dry season, redundancy of farmers and thereby affecting their livelihoods. Although there is groundwater use in the basin, it is mostly at isolated areas and mainly for domestic purposes. Hence, this study seeks to assess the sustainability of utilizing groundwater in the basin for irrigation in the dry season, in addition to the basic water demands for domestic and livestock use. In doing so, borehole logging data were obtained and used to estimate the thickness of the aquifer formation, which together with the specific yields of the different formations, were exported to a GIS environment to estimate the groundwater storage volume of the basin. The water demands, on the other hand, were estimated using a combination of the population and livestock data of the basin alongside their respective per capita water demands as well as the crop water requirements for dry season irrigation. The study estimates the available groundwater storage volume of the basin to be 1073 MCM (million cubic meters) whereas the current and 30-year future basic water demands were estimated to be 10.5 MCM and 39.4 MCM, respectively. The results further show that the remaining groundwater storage volume in the basin, after meeting the basic water demands and taking net recharge into consideration, could potentially irrigate up to 28,000 ha of farms in the dry season without compromising the baseflow to streams. Thus, the groundwater in the basin could be utilised to curb the water scarcity problems and ensure farming all year round to increase productivity and improve the livelihoods of the inhabitants.