Mechraa is one of the surface watercourses of the rural commune of Rommani. It is the main natural source of water for humans and livestock. However, it is currently threatened by the extent of urban, industrial and agricultural discharges. In order to identify the state of pollution of this watercourse, our study focused on the physico-chemical, spatio-temporal and microbiological variation (fecal and total coliforms and E. Coli). To do this, during the year 2021 seasonally, water samples were taken at five stations spatially distributed on the wadi. The results obtained describe a situation of the state of these streams is stagnant (S1, S2, S3) and the total evaporation of water downstream (S4 and S5) in dry periods. At the level of the stations where the wastewater of the municipality of Rommani is discharged, there is an increase in BOD5, chlorides, turbidity, temperature, sodium, Cl, potassium, nitrate and turbidity and a decrease in dissolved oxygen content, particularly in dry periods. The disappearance of fecal coliforms and E. Coli in the upstream (station 1) and is accompanied by an intensive increase in electrical conductivity downstream of the wadi in dry periods. Moreover, the degree of pollution differs from one station to another depending on the distance from the source of pollution.
Key words: Water, Physicochemistry, Microbiology, Pollution, Oued Machra, Morocco.