Is there a limit to how much purified water you can get from one settlement? I have about 11 water pumps and 3 industrial water purifiers and I still don't seem to be getting much water. My plan was to build up Sanctuary and not build up any other settlements. Do you have to assign workers to the pumps? The water just seems to dump in. It just doesn't seem like there's a lot of it.

well if you have supply lines between SH and lets say The Castle both have 20 people in them and you are making no water in SH and the base 40 in the castle you will make 0 extra. but if you have say 80 water making you should get some every so often. i set up SH to make 20 water with 5 people i just restarted and i usually have 10 in my workshop when i come back from doing quests. i don't think water pumps make extra purified waters only the ones you put in the river and take power to run make extras.

Water pumps don't produce excess water, regular and big purifiers will.

Do you have supply routes? They could be taking the water to other settlements.

I will say the production seems slow. I've got 10 industrial purifiers in sanctuary and have less water than I would expect, but i have all my settlements connected as well.