In West Africa, particularly in Burkina Faso, the urban freshwater bodies are amongst the most threatened exacerbating the urban environmental crises. Domestic and industrial discharges and fecal sludge are the main sources of urban water pollution. This systematic pollution, which deteriorates the physicochemical and biological condition of urban water ecosystems is a major concern for decision-makers and scientists. Thus, this study was undertaken to assess the effects of urban wastes on ecological status of physicochemical parameters et biological organisms. To do so, from September to October 2020, physicochemical and bacteriological parameters were analyzed using standard methods. Then, the macroinvertebrates were collected using hand net, and then identified in the laboratory. The results showed that the concentrations of physicochemical variables such as conductivity, COD, BOD5, nutrients and chlorides were high in downstream compared to those in upstream. The higher concentrations of total coliforms, Escherichia coli and faecal streptococci were reported in downstream. In regard of macroinvertebrates, the results revealed that taxonomic richness, the relative composition of polluo-sensitive taxa and the Shannon-Wiener index were very low in downstream. From our results, the urban freshwaters ecosystems are strongly impacted including waterborne diseases spreading, and for suitable management of these waterbodies and the well-being of riparian’s population, it is crucial to strengthen the legislation on the discharge of domestic and industrial waste, and to promote appropriate systems for the waste treatment in our cities, and to train and raise public awareness of environmental citizenship where ecology meet society.
Zio River catchment drains many cities that it receives waste, domestic and industrial effluents and its waters used to supply drinking water from downstream to upstream. Some schools use it in school canteens without treatment. Meanwhile, no study on tools of water resources management is done in this basin and whole of Togo. To fill this gap, the environmental variables and benthic macroinvertebrates assemblages were investigated to assess ecological integrity of the Zio River and its tributaries that varied in disturbance from upstream to downstream. Macroinvertebrates were sampled during four campaigns from 42 sites selected to correspond with different human activities in the catchment. The AFNOR methods were used for physicochemical analysis. Multivariate analyses (PCA) were applied to characterize sites typology and FCA for similarity between sites or taxa. The result showed that physicochemical variables of downstream sites, with the lower level of dissolved oxygen (0.6mgO2/L) and high contents of ion NH4 (5.6mg/L), KMn (30.7mgO2/L) and high Conductivity (10670