Multivariate Analysis of the Dynamics in Water Quality and Trophic Status of the Crocodile River and Hartbeespoort Dam

Economic expansion coupled with population growth and associated anthropogenic activities are a threat to water resources globally. This study assessed the dynamics in quality trophic status of one South Africa's hyper-eutrophic reservoirs, Hartbeespoort Dam. Spatio-temporal variability parameters was determined on historical data spanning period forty years (1980-2020), aim determining decadal changes Water Quality Index (WQI), Pollution (WPI), Canadian Council Ministers Environment-Water (CCME-WQI) as well Nutrient (NPI) TN:TP ratios Dam Crocodile River. The calculated indices provide single aggregated standardized score quality. efficiency bioremediation programme (2007-2012) implemented mitigation measure combat eutrophication dam assessed. also investigated impact rainfall concentration level selected physico-chemical parameters. results revealed that apart from turbidity, has no significant other studied. Furthermore, WQI, CCME-WQI, WPI, NPI classified general extremely poor highly polluted. Moreover, showed an increase TP over time, further exacerbating hypereutrophic conditions catchment. effective reducing external P loading, however, bioturbation resulted resuspension internal loads, thus maintaining high phosphate concentrations at site downstream