Were there really no wells in Amsterdam in the late 1600s?  While researching material for my book about Maria Sybilla Merian I realized that not once had I come across any reference to wells.  Nothing was mentioned in the books I read.  I had not seen any marked on old maps of the city.  Oh there was plenty of water with all of those canals, but I suspected that the canal water was salty since they did connect with the sea.  So where did the residents of Amsterdam get their drinking water?  Who could I ask?

I finally emailed the information desk of the Amsterdam Historical Museum with my question.  Frans Oehlen answered.  He answered my question and provided even more information.
As I thought, canal water was salty.  It was also polluted.  But it was used for washing, and for cleaning doorsteps.
Some people used rainwater collected in wooden rain barrels for their drinking water.  But there was not always enough.
The best water for drinking was brought into Amsterdam by water barges.  These barges brought water from the Amstel River (upstream), the Gein River, and especially from the Vecht River.  This water was for sale, though, and not everyone could afford it.  Also during the winter it could be a serious problem to keep the rivers navigable when they became frozen over.  (Ice cutters probably had a good seasonal business then.)
I had never given a thought to the possibility that people ever might have to buy water back then.  In fact I assumed that buying water was a more modern phenomenon.  I knew from traveling when I was a child that the taste of local water in various places could be quite different, but nobody ever bought and took water with them anywhere.  Only fairly recently has buying bottles and jugs of water become an option…at least in my area of the world.