Social adaptations to natural hazards in China were influenced by various social and economic factors including traditional cultures such as Feng Shui, also known as Chinese geomancy. This study examines not only the progressive processes and spatial distribution of the 1849 severe flood in Nanjing City but also subsequent countermeasures based on historical documents, maps, and digital elevation model (DEM) data. As an adaptation to extreme floods, a project that connects Xuanwu Lake to the Yangtze River was deeply debated to relieve the flood risk. Local elites and ordinary people of Nanjing City worried that the project may destroy the Feng Shui of the city, which may bring misfortune to local candidates in the Imperial Examinations, their future promotion, the prosperity of their families, and the development of the local society in the city. This indicates that, in the complicated traditional Chinese society, such traditional cultures may play an important role in determining social adaptations to climate change. However, these traditional cultural concepts may not lead to a consensus without specific institutional culture. Hence, in the complicated social background, the institutional culture was also fundamental to build social adaptations to climate change. The project that connects Xuanwu Lake to the Yangtze River was eventually completed in 1931, which shows that the cultural concepts are dynamic in a complicated traditional society and are continuously changed along with the influence of institutional changes, educational development, and the guidance of the media guidance.