This study's objective was to assess pollution by characterizing the urban wastewaters released in the Oued Beht of the town of Sidi Slimane using physio-chemical and microbiological methods. This study had two main goals: first, to address the question of how raw sewage should be treated; and second, to raise awareness about the contamination of the Oued Beht, a local source of irrigation. Water samples were collected and analyzed for temperature, salinity, pH, suspended particles, and the oxygen requirement of biological and chemical processes. According to physico-chemical tests, the average pH of the wastewater in the upstream and downstream locations is 7.63 and 7.72, respectively. The average electrical conductivity value ranged from 730 to 2210μS/ cm, and the measured values were determined to be between 6.5 and 8.5, which is the top limit for direct discharges. The biodegradability of these effluents was shown by the ratios DCO/BOD5, DBO5/DCO, and MES/DBO5, which also allowed for the selection of an appropriate treatment technique. The BOD5 ratios were 22 and 140mg/ L, while the COD ratio was 61: 316mg/ L. In fact, the data indicated that home effluents surpass the national rejection criteria. It necessitates the involvement of the appropriate authorities to maintain environmental protection, public health, and the installation of an effective sewage treatment plant to guarantee sustainable development.