This study examined the physicochemical characteristics of water from the Tshopo River before it entered the REGIDESO SA/Kisangani treatment plant in the Democratic Republic of Congo during the year 2024. Sixty samples were collected and analyzed, with five samples taken each month at five- to seven-day intervals. Temperature (in situ), pH, turbidity, color, conductivity, oxidizable matter content, total alkalimetric titration, total hardness, free chlorine, nitrite ion content, and chloride ion content were evaluated. The following annual average values were obtained from these physicochemical analyses: temperature 26.97 ± 0.78°C; pH 6.5 ± 0.34; total alkalimetric titration 0,0± 0,0; turbidity 2.42 ± 0.30 NTU. colour 8.4±0.30PtCo; conductivity 32.65±3.96µS/Cm; oxidizable matter content 1.75, ±0.26mg/L, alkalimetric titer 0.33±0.12°F, total hardness 0.07±2.03°F, free chlorine 1.13±0.38 mg/L, nitrite ion content 0.02±0.01mg/L and chloride ion content 3.78±0.43mg/L. These water quality parameters showed highly significant differences between the four rainfall seasons of 2024, except for pH, simple alkali-sensitivity, oxidizable solids content, total hardness, nitrite ion content, and chloride ion content (respective p-values of 0.216, 0.441, 0.925, 0.598, and 0.483). This work contributed to highlighting the impact of treatment by REGIDESO SA/Kisangani on the physicochemical quality of the Tshopo River water at the REGIDESO SA/Kisangani plant. It would be important to replicate this study over three years to assess the plant's performance.