Tianjin, as one of the least per-capita share of freshwater resources in China, is a city with severe water shortage, and is also one of the most serious land subsidence areas in China. Land subsidence has become the major geological hazard in Tianjin. There are many depressed areas in Tianjin plain, most of which are wetlands. Building emergency groundwater well fields in depressed areas can supply water for the urban, relieve the land subsidence in urban areas and improve the environment of the depressed areas.