Rainwater Harvesting System Case for Huzhou National Development Zone New Energy Industrial Park | Zhengzhou Yayuan Technology
Project Background
Located in Xiaohuangshan Unit, South Taihu New Area, Huzhou City, the Huzhou National Development Zone New Energy Vehicle Industrial Park serves as a core hub for regional new energy vehicle industry clustering. Following the sponge city philosophy throughout construction, the park prioritizes the rainwater harvesting and reuse system as a key supporting infrastructure component. Leveraging its technical expertise in PP module rainwater harvesting and rich cross-regional project experience, Zhengzhou Yayuan Technology undertook the detailed design, construction and installation of the park’s rainwater harvesting system.
Project Challenges & Solution Selection
The industrial park features large single factory buildings with extensive roof catchment areas, together with dense underground pipelines, imposing strict requirements on the load-bearing capacity and space adaptability of water storage facilities. After on-site survey, the technical team of Yayuan Technology adopted honeycomb hollow 3D PP rainwater harvesting modules as the core water storage units. These modules achieve a void ratio of over 95% and a load capacity of 60KN/㎡. They enable the construction of a water tank with ample effective volume within limited underground space, while meeting the backfill and load requirements under the park’s heavy-load pavement and green belts.
At the front end of the system, sediment intercepting baskets and rainwater flow diverters are installed to intercept pollutants and divert the initial flush runoff from roofs and pavements, controlling water quality entering the storage tank at the source. The PP module tank is wrapped with geotextile and impermeable membrane to prevent soil particles from infiltrating and clogging the voids of modules, guaranteeing stable long-term operation of the tank.
Key Construction Stages
Foundation pit excavation and base treatment mark the first critical construction phase. In accordance with design elevations, the team carried out layered excavation and reserved a layer for manual trimming to avoid disturbance of undisturbed foundation soil caused by over-excavation with machinery. After compaction of the pit base, a plain concrete cushion was laid to provide a flat and stable working surface for module assembly.
During module assembly and pipeline connection, workers assembled PP modules layer by layer in staggered joints to form the skeleton of the integrated storage tank as per construction drawings. Modules were locked together with special connectors, and side panels were installed around the tank to restrict displacement. Inlet pipes, outlet pipes, overflow pipes and drain pipes were connected to the tank at designated elevations, with all joints sealed properly to eliminate leakage risks.
Impermeability treatment and backfill directly determine the tank’s watertightness and structural safety. After module assembly, geotextile and impermeable membrane were laid in sequence. The lap width of membrane materials complied strictly with specifications. Hot-melt welded seams passed air tightness inspection before backfill. Sand soil was used for layered compaction backfill. Fine sand or soft soil was applied within the 50cm zone surrounding the tank to prevent sharp stones from damaging the impermeable liner.
System Commissioning & Acceptance
Upon construction completion, the team conducted a full water test and pipeline flow test for the whole rainwater harvesting system to verify tank watertightness and smooth drainage. The flow diverter, filter and disinfection equipment were commissioned with normal linkage. The effective storage capacity and treated water quality indicators met all design specifications. After handover, the collected and purified rainwater can be reused for park green irrigation and road washing, cutting municipal tap water consumption and aligning with the low-carbon operational positioning of this new energy industrial park.
Project Value
This project represents another successful implementation of Yayuan Technology within a national development zone in the Yangtze River Delta. Cross-regional construction coordination and consistent technical standards from the Zhengzhou headquarters to the Huzhou site have been fully validated. The completed system not only adds sponge city functionality to the industrial park, but also delivers a replicable construction reference for underground rainwater storage and reuse facilities in similar new energy vehicle industrial parks.