Groundwater recharge and potential exploitation in the Densu basin, Southwestern Ghana

Abstract

Recharge estimation is important to the effective development and management of groundwater resources, since it forms the basis for assigning abstraction rates. This study applied the water table fluctuation method and chloride mass balance approach to estimate groundwater recharge in the Densu basin, identified as the most problematic and vulnerable catchment in Ghana, using chloride and water level data from 10 monitoring wells. In general, the results revealed seasonal and spatial variation in groundwater recharge in the basin, with a north-south decreasing trend. The chloride mass balance approach and water level fluctuation method revealed average groundwater recharge of 70 mm and 62 mm/year respectively. With the total groundwater abstraction in the basin estimated to be only 8% of the annual recharge rate, the potential for groundwater use in the basin is great, granted adequate water quality assessment supports the useable quantity available in the basin.