Together with Prof. Dr.-Ing. Helmut Grüning from Münster University of Applied Sciences, Humberg GmbH is developing underground rainwater storage tanks in the root zone of trees in the BeGrüKlim project. These are filled via the existing drainage system, for example with rainwater run-off from car parks or the roofs of adjacent houses. If it then becomes very hot and dry, the trees are efficiently watered via the systems.
For this purpose, sensors monitor the fill level of the retention tanks and the moisture level of the substrate. The data can be sent wirelessly via the mobile phone network to the responsible department of the city administration, so that employees can specifically refill empty "tanks" under trees if it has not rained for a long time. On the other hand, during heavy rainfall, the water can first fill up the underground tank before it flows into the sewage system. This relieves the burden on the sewage system. In addition, the trees reduce the heat island effect in the cities through their transpiration.