Infiltration concept For a return to the natural water cycle
Currently, the cities are sealed over a large area and offer little compensation area. Large cities such as Munich already have a sealing rate of 46.6%. The precipitation therefore rarely seeps into the ground, but is mainly discharged via the canal.
Since the water does not seep away everywhere and is instead discharged via the sewer, the sewer system can be overloaded during heavy rainfall events. In addition, the groundwater supply is steadily decreasing, as only a small amount of water is supplied. Instead, more than 70% of Germany’s drinking water comes from groundwater, so that the water supply continues to decline due to consumption, as well as climatic and building conditions.
In addition, asphalt roads have been proven to have a higher temperature of up to 12 °C compared to water-bound pavements, as they store heat. The average temperature of the asphalt surfaces in summer is over 45° C, so that so-called heat islands form over a large area with little vegetation.