@Walter Hinteler,
There are quite a few pumping stations in Potsdam (and neighboring parts of Berlin) - not surprising, since their are/were quite a few castles around there.
One of my favourites is the
Dairy in the New Garden: originally the dairy to supply the royal court, with stables and sheds for the cows, grazing on the surrounding land to produce milk for the manufacture of butter and cheese.
In 1857 the buildings were slightly changed to become the engine or pump house to water the New Garden.
In 1928 a restaurant was established in the building making it the most popular café, beer house and restaurant in Potsdam until WWII.
Since the early 1990's is a restaurant and café again - said to be the most beautifully situated brewpub in Germany
(In the front, the "water taxi" is a regular public transport line)