The use of rainwater in private households reached a peak in the 1990s, but the droughts of recent years in Germany have brought this technology back into focus. Many people are becoming aware that drinking water is too valuable for watering the garden or flushing the toilet, even for the washing machine at home. Of the 130 litres of water that every citizen statistically consumes per day, more than 50 litres are for the latter purposes and therefore ideal for the use of rainwater. Rainwater utilization systems consist of a storage tank, a filter, the corresponding separate pipe system and a pump. The rainwater collected on the roof reaches the storage tank through pipes and can then be directed to the respective consumers with the pump. Rainwater utilization conserves water resources, relieves the sewerage system and sewage treatment plants during heavy rainfall and helps to reduce the risk of flooding.