Satellite data show that Germany has lost water to the extent of Lake Constance in 20 years. A few clever tricks around the house and garden will help.
It is best to water in the early or late hours of the day. If you can, you should collect rainwater, e.g. in a bin. This allows plants to be watered wonderfully (and inexpensively) In the garden, a layer of mulch over the soil ensures that it does not dry out so quickly - and you do not have to water again so quickly.