Kaohsiung City is the second largest city in Taiwan and suffers from serious floods during the wet season, but it also badly needs water during the dry season. As economic development advances and pollutants increase, water pollution and shortage of water resources become issues of concern for local people in Kaohsiung. A project has been proposed by the city government and executed by the authors to establish a system of sustainable water management in urban areas. In this system, the Caogong Canals, irrigation channels which were established 170 years ago during the Ching Dynasty of China and are still used today for irrigation, were renovated to bring stable and clean water to the urban areas. It is planned to pump clean water into the canal from a river near the city. In this project, 12 constructed wetland systems, functioning as wetland parks, stormwater storage tanks or eco-detention ponds, were built in the city, and the Caogong Canals are planned to connect all these urban constructed wetlands in the second stage of the project.