Impact of a small hydropower plant on water quality dynamics in a diversion and natural river channel

This study innovatively evaluates the impact of hydropower plants located in a diversion channel on water quality dynamics. The spatial characteristics of water in the diversion channel above and below a hydropower plant were assessed; specifically, the investigation was conducted in the watercourse undeveloped by the hydropower plant and at reference points. Among the five analyzed points, the strongest statistically significant changes were observed in electrical conductivity, pH, and dissolved oxygen. Statistical analyses showed a similar, statistically significant relationship for most months. The water quality indicators proposed in this study help assess hydropower plants’ impact on water quality dynamics because they enable water comparison at different locations. The best water quality, as calculated using designated indices, was recorded below the hydropower plant. Among the physicochemical parameter values, the most noticeable change occurred in dissolved oxygen below the hydropower plant and below the fixed weir; its value was 8.10 and 5.32% higher in the two locations at the reference point below the hydropower facility. Moreover, the NH4‐N content was higher by 7.06% below the weir than the point below the hydropower plant. In the long term, this research may help plant operators manage water resources on watercourses with hydropower development more efficiently, according to sustainable development principles. This research will contribute to the rational management of such facilities on diversion channels considering sustainable water management principles. Core Ideas This research will contribute to the rational management of diversion hydropower facilities. Significant changes in conductivity, pH, and dissolved oxygen within research points were noted. There has been an improvement in the water quality indices below the hydropower plant. Water quality indices enable its classification and standardization within hydropower plants. Better water quality occurred in the diversion channel than in the natural parts of the river.