# Sustainable Urban Water Management in China: A Case Study from Guangzhou and Kunming
## 4 Linkages between the Urban Water System in Guangzhou and Kunming  
Many stand-alone ecosystem services are now provided by a combination of more distantly linked ecosystem services (e.g., the constructed waterways) that transfer water to cities and agriculture wetlands. These services are also linked to drinking water treatment plants, manufacturing industries, and recreational sites, and they are made up of a variety of interconnected physical elements and infrastructures (e.g., water treatment plants, water and sewage infrastructures) [46]. The cities' numerous water systems are designed to be interconnected. If a single component cannot be resolved in its whole, the entire city water system will become entangled in a vicious spiral. The amount of sewage produced is proportional to the amount of water consumed. Due to Guangzhou's growing population, the more water that is consumed from the water supply system, the greater the pressure on the drainage and sewage systems. Additionally, because many pipes are located beneath roadways, pipeline maintenance may clog roadways and disrupt traffic. Residents and farmers in Kunming's urban areas receive their water from neighboring reservoirs, which are surface water resources. While the natural water supplies are plentiful, insufficient water conservation facilities are less likely to deal with extreme dry seasons in specific years, affecting the urban water supply problem. As a result of the drainage system's development, the number of separate drainage systems has increased, which benefits both the river and wetland water quality. Rainwater flows directly into the river, therefore, it is possible to ensure that all sewage is directed to sewage treatment plants and subsequently to the wetland following its treatment. Additionally, it helps to alleviate the demand on sewage treatment by reducing wastewater production.  
Due to advancements in ecological technology at sewage treatment plants, the outflow water quality can be enhanced, thereby reducing water pollution in wetland areas (Figure 2). Additionally, employing fewer insecticides and planting organically grown crops/plants can help improve the wetland's water ecology. Finally, fostering collaboration between private businesses and the government to manage a wetland and conduct research on biological and ecological technologies can alleviate economic pressure and spur innovation. Additionally, the stakeholders in this region include not only individuals and government, but also businesses. Thus, when the relationship between the city's components is considered, development can proceed on the predicted path.  
From a shared beneficial perspective (Figure 3), the benefits of collaborative projects manifest not only in terms of science, technology, and the environment, but also in social, economic, political, and climate-related dimensions. For instance, incorporating steps to mitigate urban heat island impacts into Sponge City building might promote public participation, hence, consolidating funds for public-private partnerships. The water sensitive city construction in Kunming and Guangzhou has several benefits, including the reduction of water pollution, the purification of sewage by natural processes, and the effect of natural purification on biodiversity. Flowwaters have an adverse effect on people's daily lives and economic activity, impeding social development and policy execution.