Rivers play a critical role in regional water quality, but from time to time concentration of surface water pollutants can easily exceed both national and local water standards. This study debates the feasibility and effectiveness of utilizing the natural treatment potential of flowing river water by replenishing treated sewage effluent and forced circulating. The research combines field experiments and laboratory analyses to assess the impact of this approach on water quality. Theoretical simulation with one-dimension modeling recommended by China’s national standard of “Code of Practice for Computation on Allowable Permitted Assimilative Capacity of Water Bodies” (GB/T 25173-2010) indicates that the target campus river water’s cycle flowing contributes to the further removal of key pollutants from treated sewage, resulting in the improvement of campus river’s water quality downstream along its forced circulation. NH3-N and CODMn levels of the campus’s river water were notably reduced and met the planning water qualities as expected.