In the summer of 2016, 19 of the 30 pilot sponge cities tasked with strengthening urban flood-control capacity experienced waterlogging. In response, the official website of the Ministry of Housing and Urban-Rural Development published an article stating that sponge city construction will not produce immediate results or be achieved overnight, and that sponge city construction is still being accelerated.
　　The sponge city is a relatively advanced concept of urban construction. In October 2015, the General Office of the State Council issued the Guiding Opinions on Promoting Sponge City Construction, proposing that through sponge city construction, comprehensive measures such as “infiltration, detention, retention, purification, utilization, and drainage” should be adopted to minimize the impact of urban development and construction on the ecological environment, and to absorb and utilize 70% of rainfall on site.
　　Comprehensive Analysis
　　Sponge city is a figurative expression; the internationally used term is “low-impact development rainwater system construction,” which means that a city, like a sponge, can absorb, store, infiltrate, and purify runoff rainwater on site or nearby when it rains, replenish groundwater, and regulate the water cycle; during droughts and water shortages, it can release stored water and put it to use, thereby making the movement of water in the city more “natural.”
　　In recent years, waterlogging whenever it rains and “watching the sea in the city” have become endless troubles for many cities amid rapid expansion. The reason lies in some unscientific planning and construction that has disrupted the natural law of the water cycle. With the rapid advancement of urbanization, people's requirements for urban construction and management are becoming higher and higher. Urban waterlogging caused by extreme weather such as heavy rainfall seriously affects people's normal lives, so people expect governments at all levels to take measures to solve this problem. As an important measure for controlling urban waterlogging and systematically solving the problem of urban water resource utilization, the “sponge city” project naturally carries many citizens' expectations. In the past, urban construction and development often had the problem of being “fast but chaotic.” On the one hand, after infrastructure was built, there was a lack of communication and coordination among departments, frequent repairs and reconstruction, and the long-standing “road zipper” problem, which seriously affected people's normal work and life. On the other hand, some image projects that only care about “face” and ignore the “inner workings” ran rampant; they looked splendid, but in fact had many internal problems, and going back to renovate them had already become too difficult.