Hydrological cycle, a dynamic process, which constantly proceeding through evaporation and precipitation, maintains the natural balance of biosphere. In a natural environment, stream flows are stable and runoff velocity is slow. Ground water infiltrated soil and became part of underground water. Nevertheless, human intervention has significantly affected the natural balance of hydrological cycle. Impervious paved surface blocked the infiltration of runoff water and accelerated the hydrological cycle. As a result, a large volume of runoff water carried various urban pollutants as well as precious soils from urban landscape, which leads to severe environmental problem.
So how should we manage storm-water in urban neighborhood and make water cycle become a sustainable measure?
I think the main focus lies in connecting natural process with urban society. In fact, we should reveal the natural hydrological cycle in urban environment and utilize sustainable methods to tell people the importance of managing storm-water and keep the balance of water cycle. For instance, we can build bio-retention pond or rain garden at open space in urban area. After rainstorm, the ponds and gardens will accumulate a great volume of water, which will attract numerous children playing water in the open space. This is the best time to let them know how hydrological cycle works and how important the gardens and ponds of managing water.
Besides, using porous paving materials to build roads can not only maintain enough strength for driving but also enable storm-water infiltrate the surface to replenish underground water. In addition, introducing sewage treatment plants in urban area is also useful. However, all these measures should be exposed to urban residents constantly. It needs continuous involvement as well as the cooperation of local communities and development agencies.
Michael Hough. Cities and Natural Process, Chapter: 2. Water, 2004, pg:5-25