As Wind, Storm and Tide Meet: Strategies and Plans to Tame the Issue of Urban Flooding for the City of Ningbo

Ningbo is a large seaport city located on the east coast of China with a population of 3.5 million. In recent years, Ningbo has been plagued with major urban flooding issues, which have caused human life losses as well as billions of dollars of losses in property values. The root causes of the issues were investigated using various modeling tools, and strategies and plans were developed. It was found that the unique geographical and hydrological setting in the area played a major role in these issues in addition to problems that are commonly seen in other cities with comparable sizes, and the existing sewer system, dominated by gravity pipelines, can no longer accommodate the rapidly urbanized city. Solving the urban flooding issue requires a comprehensive plan that takes into account basin-wide planning, localized improvement measures for the municipal drainage system, and effective coordination between the two systems.