The Turbidity Timeline of Prah River and Ankobra

The Turbidity Timeline: River Prah & River Ankobra

The turbidity timeline illustrates changes in water clarity in the Pra and Ankobra Rivers from 2009 to 2024, highlighting the effects of illegal small-scale mining (galamsey) on these major river systems in southern Ghana. Turbidity, measured in Nephelometric Turbidity Units (NTU), indicates the level of suspended sediments and pollutants in water.
The data reveal a steady increase in turbidity beginning around 2016, coinciding with intensified galamsey activities along both river basins. The Pra River shows an extreme spike in 2022, reflecting the peak of riverbed dredging, while the Ankobra River also records high values around 2021–2024, particularly near Prestea.
Although government interventions such as “Operation Halt II” have slightly reduced turbidity levels in recent years, both rivers remain far above safe ecological and drinking-water standards. The timeline therefore provides a visual summary of the progressive degradation of these vital water resources due to uncontrolled mining practices