Modeling the environmental and economic impacts of dredging on river Manafwa

Abstract

The environmental implications of dredging River Manafwa in Eastern Uganda, a critical water source supporting agriculture and local ecosystems, remain underexplored despite increasing dredging activities. This study aims to assess the impact of dredging on water quality, focusing on parameters such as turbidity, pH, dissolved oxygen, and heavy metal concentrations, while evaluating sedimentation's influence on water treatment costs. Utilizing baseline water sampling at multiple river sites, pre- and post-dredging data was analysed to identify shifts in water quality, employing multivariate statistical methods to isolate primary influencing factors. Hydrodynamic modelling through HEC-RAS facilitates the simulation of dredging impacts on river flow and sediment transport, providing predictive insights into potential downstream water quality deterioration. Additionally, sediment sampling and filtration efficiency tests was conducted to assess the increased demands on water treatment infrastructure caused by dredging-related sediment resuspension. (Results and findings and what they mean in summary) This research was contributing valuable data to guide sustainable dredging practices, mitigate ecological impacts, and support water quality management in alignment with Uganda's National Development Plan and SDG 6, promoting the sustainable management of water resources. The findings aim to offer a framework for minimizing dredging's adverse effects on water quality, benefiting both environmental health and community livelihoods.