With the continuous development of the social economy, the global resources are consumed quickly, especially life-giving on our planet – water resources. It is understood that most countries in the world are in a situation of water shortage. As a natural renewable resource, can get enough water resources through rainwater harvesting. Rainwater harvesting is a green environmental protection project with light pollution, which plays a role in alleviating urban water shortage. Rainwater harvesting plays an important role in improving urban natural ecosystems. Modern urban rainwater harvesting is a large-scale comprehensive new-generation technology that can save water, facilitate the storage of water resources, reduce urban soil erosion and water-logging, greatly reduce water pollution, and improve urban ecological balance effect.

Water resource is basic important natural resources of human beings. Rainwater harvesting is one of the controlling factors of ecological environment; and is an important pillar resource of strategic economy. Rainwater harvesting is an organic component of a country’s comprehensive national strength. With the current urbanization economy in a period of rapid development, the contradiction of insufficient resources, the rapid development of urbanization and the increasing population of the city. The demand for urban water consumption has further increased,;on the other hand, the urban impervious area has gradually expansion, which led to an increase in the loss of rainwater resources a disruption of the balance water cycle system.

Due to the particularly poor quality of rainwater on the surface of the earth, most of it used in reservoirs on the system. Rainwater harvesting is used for greening water and landscape water in the combined drainage system. The ground rainwater collection method includes the green area to replenish the underground water system in the old city. If the rainwater near the ground is collected and transferred to the underground, it will not only reduce the pollution level of the environment, but also increase the treatment efficiency of the urban sewage plant and reduce the treatment cost. It is better to use the diversion system. The ground rainwater flows into the special pipeline of rainwater from the water collection port through the runoff, and then directly into the rainwater storage tank , which is relatively simple.