It's astonishing, from a North American perspective, to see the word "free" in front of drinking water. As I mentioned on a few occasions on my European road trip, locating any kind of drinking fountain in zoos throughout the Netherlands, Germany or Belgium was virtually impossible. By contrast, most North American zoos have half-a-dozen "free" drinking water options across their grounds. The combination of constantly buying drinks, plus paying for a large number of zoo maps, were fees that racked up my European trip bill. Those sort of things are almost always free in North America.
Without being to harsh, did it not occur to you that you could fill your bottle, or even bottles, at your accommodation every morning before setting out?
@FunkyGibbon For sure that occurred to me, and it was advantageous to have a full bottle of liquid before arriving at a zoo on several occasions. However, I like to travel light when visiting 95 zoos in a month and I have a tiny camera that slips into my pocket and then essentially nothing in my hands other than a zoo map. It is an enormous inconvenience not to be able to have plenty of drinking fountains across the grounds at zoos and it was a major cultural shock as at hundreds of North American zoos water is "free" just about everywhere. When I first started going around Dutch zoos, with visitors casually puffing away on cigarettes and no drinking water anywhere, it was a massive shock to my system. By the time I reached Belgium, with 8 year-old kids smoking two packs a day and parched mouths in all directions...it was even more outrageous! *
When I visited Krefeld Zoo just after yourself I had to carry my 15kg backpack all the way around the zoo because the staff were adamant there was nowhere it could be stored!
Incidentally, as I think was mentioned in your trip thread, you can just refill your bottle from taps in bathrooms as well, and if you really want to travel so light you don't carry a bottle then you could just drink from them as well.
