When it rains in Berlin, some of the water ends up in the sewerage system, some of it evaporates and some seeps into the ground. Below the ground, it makes its way into the groundwater. Impermeable rock layers may block its path and divert it. New groundwater formation (groundwater recharge) describes the water that makes it to the ‘bottom’.
The success of this process depends on many factors. Is the ground paved? What kind of rock layers are waiting underground? What is the distance between the surface and the groundwater? And how much rain is actually coming down? In Berlin, the levels of new formation fluctuate greatly. The precipitation volumes that seep away in the end depend primarily on vegetation, soil and depth to the water table, impervious coverage and how much of the area is connected to the sewerage system.
About a fifth of Berlin’s precipitation reaches the groundwater. Currently, 118 million cubic metres of groundwater are newly formed every year. In 2003, it was as high as 130 million. It is important to keep an eye on such developments because climate change impacts upon the water balance. Discover in the following, which areas facilitate new groundwater formation and what it depends on specifically.
