When I first moved to Germany in the 1970s, everyone bought their water in crates of 12 glass bottles. The Germans hate still water so the default is.always sparkling. I always assumed.this was.a.throwback to the post-war days when conditions were dire and tap water really was not reliable. It takes a long time to get it into people's heads that tap water is the cleanest option. My parents in law probably never did believe it.
A deposit was paid on the glass bottles and crates, but most people just swapped one for the next one, so you just paid for the water each time. Then plastic bottles were slowly introduced like in the rest of the world. Nowadays Soda Streams are very popular and most people have them so they can still have their water sparkling.
All drinks containers, cans, plastic and glass bottles and crates, now have a deposit on them and you feed them into a machine on your way into the supermarket and get a voucher which you can cash at the till. People bring huge bin liners full of plastic bottles and put them in the machines, so they are bringing back the light plastic bottles. I really don't see why - they must be drinking gallons of Coke or Fanta, or perhaps it is water, it should be banned.