he urban water system is a rare natural resource in the city, which has a profound impact on the economy, life, and environment of the city. At present, the reform of the land space planning system also makes the systematic planning of blue-green space composed of green space, water system, and wetland a greater concern. Based on the function factors of the water system in the city, this paper studies the influence of the water system on the formation and development of a city from four aspects: urban morphology, urban environment, urban style and features, and urban culture. On this basis, combined with the water system characteristics of Sihong County, Jiangsu, this paper analyzes the utilization potential of flood resources in Sihong County from three aspects of urban morphology, environment, and huge cultural features. Aiming at the construction of the water charm of Sihong County, the paper puts forward some urban governance suggestions, such as hugging the lake into the city, formulating the characteristic ecological water system management, and integrating “water venation-green venation-culture venation”.