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

Zio River, Togo, physicochemical quality, biological index, macroinvertebrates, sensitivity