Analysis of Utilization Status and Reuse Potential of Low-Pollution Water in Northern Area of Fuxian Lake Basin

To promote the resource utilization of low-pollution water in the northern area of the Fuxian Lake Basin, the total volume of low-pollution water in 2021 was calculated based on data regarding urban sewage treatment plants, meteorology, and agricultural irrigation. The calculation focused on two sources: tailwater from urban sewage treatment plants and farmland runoff drainage. Combined with field investigations, the current status of utilization and the potential for reuse were analyzed. The results indicate that① In 2021, the total volume of low-pollution water generated in the northern area was 28.924×10⁶ m³, with a reuse volume of 2.6004×10⁶ m³, resulting in a reuse rate of 8.99%. The tailwater from sewage treatment plants was primarily used for agricultural irrigation, followed by urban miscellaneous and landscape water use. Farmland runoff drainage was mainly reused for irrigation through the constructed storage belt on the north bank.② The total available potential for low-pollution water reuse in the northern area is 26.3236×10⁶ m³. Of this, sewage treatment plant tailwater accounts for 28.43%, while farmland runoff drainage accounts for 71.57%. Future efforts should focus on increasing the use of sewage treatment plant tailwater for wetland replenishment, urban miscellaneous purposes, and landscape water. Low-pollution water can be reused for agricultural irrigation by utilizing the reservoir-pond wetlands, storage belts, and reuse pumping stations in the northern area.③ To effectively promote the reuse of lowpollution water, it is essential to establish a cyclic reuse system, strengthen synchronous monitoring of water quality and quantity, and rationally upgrade reservoir-pond wetlands to ensure their effectiveness. Comprehensive utilization of sewage treatment plant tailwater, farmland return water, and initial rainwater should be strengthened to promote a comprehensive green transformation of economic and social development in the basin.