Groundwater Quality and Vulnerability Assessment in the Nakivale Sub-catchment of the Transboundary Lake Victoria Basin, Uganda

This study evaluates groundwater quality in the Nakivale sub-catchment, focusing on the inter-play of anthropogenic and geogenic influences. Hydrochemical analysis of 19 groundwater sam-ples revealed that 90% comply with World Health Organization drinking water standards, alt-hough localized contamination concerns were noted, particularly with total iron, nitrate and magnesium. Groundwater quality index indicated that over 90% of the samples fall within good to excellent quality categories. Alignment of nitrate levels with elevated chloride-bromide ratios suggest human impacts, likely from agricultural runoff and wastewater disposal. The irrigation groundwater quality assessment showed that 94% of samples possess low sodium, and medium to high salinity hazards, which could threaten crop productivity due to increasing osmotic stress. Vulnerability assessments indicated low contamination risks, attributed to overlying impermeable geological features, steeply sloping landscape, slow groundwater recharge, high depth to aquifer and clayey soil cover. The findings underscore the necessity for conjunctive management of water resources, incorporating strategies such as enhanced monitoring of groundwater quality, public education on sustainable practices, and protective measures for recharge zones. By addressing these concerns, the study aims to safeguard groundwater resources for both domestic and agri-cultural purposes, ensuring long-term sustainability in the region.