Stormwater Management in Urban Areas

In an anthropogenically intact country, almost all stormwater (SW) is infiltrated, and it is absorbed by plants or evaporated. While SW in urbanized areas hardly finds an unaffected path to reach the natural water cycle, the natural water cycle has changed due to the buildings and roads associated with the growing population and also due to agricultural and forest management. This leads to a gradual change of underground water with a structural change and in extreme SW leads to local flooding. The current dry weather in the Czech Republic (CR) accompanied by extreme weather fluctuation provides the necessity to deal with stormwater management (SWM). Therefore, it is necessary to reduce the surface runoff and then consider connecting the SW to the sewer system or the watercourse. The implementation of the water policy of the European Community is subsequently the basis of legislation in the CR with technical measures for SWM: SW pretreatment, SW retention, and SW infiltration. The average demand for drinking water is over 100 L water per capita per day. However, about 50% of this need does not need to be drinking water. Thus, SW can be used as a replacement for toilet flushing, irrigation, washing, and other use.