The drought delivers its most impressive images precisely from the bottoms of dried up rivers.
But it should also be an occasion in the cities to think about long periods of drought.
For weeks now, the parks in Frankfurt have looked like the Californian desert, the summer is ocher, not green.
Acute drought does not necessarily mean that there is less precipitation on a yearly basis, but the distribution is much more extreme.
Cities must respond to this with the appropriate blue-green infrastructure.
The solution is not to think in terms of drainage concepts and to first call for a more efficient sewage system the next time it rains heavily – the counterpart to a drought.
In times like these, wide sewers mainly lead to stinking gullies.
The sewers take rainwater out of the cities, but we have to make sure that the rain is collected where it falls as much as possible.
Asphalting less, planting more is a logical approach.
There are also technical solutions, ranging from buried rainwater tanks to innovative roof constructions.
Berlin, for example, affords a rainwater agency that has developed a process to turn flat roofs into sponges.
Underneath a green roof area is a frame that resembles beverage crates and whose cavities fill with water when it rains before excess flows into the gutter.
Something like this does not prevent every emergency, there are droughts, for which even the rain collected in recent weeks is not enough.
But stockpiling used to be a matter of course, as was using valuable resources sparingly.
Rainwater, that much is now clear at the latest, must be part of it.