A closed urban scenic river system using stormwater treated with LID-BMP technology in a revitalized historical district in China

Urban river restoration is becoming a concern as a result of economic development. One scientific focus is how to restore urban river systems by integrating principles and practices of land use planning, landscaping, aquatic environmental protection, and flood control. A river revitalization project in a historical district in Suzhou City, Jiangsu Province, China is used here as a case study. The study demonstrates the development of a systematic solution that integrated knowledge of urban planning, landscape ecology, environmental science, and hydrology. In accordance with a low impact development (LID) strategy, the planning objectives were designed to give the district the ability to maintain the quantity and quality of the closed scenic water system and to reduce risks of flooding. Low impact development best management practice (LID-BMP) facilities were selected, placed and designed based on landscape planning and the other factors listed above. A model based on the storm water management model (SWMM) was developed to assess the water quantity and quality benefits to be expected by implementing the LID-BMPs under different storm scenarios. Based on an investigation of the pollution sources and the design of the water system, water quantity requirements were then estimated. Deployment of sources for the water system and a water quality maintenance scheme were proposed. In addition, according to the SWMM modeling analysis, although the stormwater pipe system in the district met only the standard required for 2-year recurrence-interval storms, there would be no local flooding in a 5-year recurrence-interval storm, and the local flooding situation would not be serious even when a 20-year recurrence-interval storm occurred.