To address the imbalance between water supply and demand in the region, Huai'an has innovatively explored a cross-regional and cross-sectoral serial water supply model in recent years. The city has prioritized the implementation of a water efficiency improvement project in the Huaiyin District Industrial New Area, establishing a water resource utilization system that transforms upstream salt production wastewater into a water source for downstream mining operations, thereby achieving a win-win outcome in terms of ecological, economic, and social benefits.

The water efficiency improvement project in the Huaiyin District Industrial New Area covers Huaiyin District, the Huai'an Industrial Park, and Hongze District. With a total investment of RMB 300 million, the project involves the construction of approximately 33 kilometers of cross-regional water transmission pipelines and involves 11 industrial enterprises across various sectors. It specifically addresses the industry-wide challenge of high water consumption associated with water-soluble mining processes, using wastewater recycling as a breakthrough to establish a closed-loop water system. Specifically, this involves collecting wastewater from upstream enterprises, treating it, and directing it to injection wells in the mining area to achieve the recycling of wastewater. At the same time, the project collects its own wastewater and the treated domestic sewage that meets discharge standards, and recycles them through processes such as sedimentation for brine extraction, thereby achieving “zero discharge” of industrial wastewater throughout the entire process and reducing water consumption and pollutant emissions at the source.

Since the project began, it has achieved significant results in water conservation and efficiency improvements. The project reduces annual new water withdrawals in the covered area by approximately 10 million cubic meters; by 2025, the actual water reuse reached 8 million cubic meters, effectively supplementing the region's water resources. Participating companies have seen a significant reduction in operating costs; in terms of water charges (taxes) and sludge disposal and related wastewater treatment fees alone, they save over RMB 3 million annually, resulting in a continuous improvement in market competitiveness. At the same time, the volume of industrial wastewater discharged has been significantly reduced, the risk of water pollution has been effectively controlled, and the regional aquatic ecosystem has continued to improve.