Hi CA, I've been following this thread and didn't really know what to offer you but I did have a thought since it seems you are really having a hard time of it. As others mentioned about the current manager sharing the information with your mother, you "may" actually be able to use that as some leverage in your case right not.
How? Let me share with you. First of all you can approach it from 2 angles. The first, if you choose, is perhaps the best one for you if you WANT to stay put. Write up a letter and get it notarized stating your intent to take legal action against them for sharing private financial (and if there was other personal information) with another party that was an illegal violation. I may be able to find an actual statue in the law for CA for you before Monday but if others would assist it would be appreciated too as my time is limited. At the bottom, make sure you put CC/attorney. Yes I put that right just "attorney". You won't need a name in this case. Present that to the manager of the complex. Explain to him that since he violated your rights you are requesting that either A) he allows you to remain on the property with a new lease(essentially giving you a 2nd chance with the water bill situation and you can literally say this if you like) or B) he allows you to remain until you can find suitable housing otherwise and have not been able to obtain such at this time and have a minor child to consider. It's his choice (and the properties) if they seek to undertake a law suit or would rather settle this equitably. Chances are, I bet they settle. Let him run it by their lawyer too because the law IS on your side at this point in time. The other thing that can be added is, if you can look in your handbook or lease itself, is if there is anything WRITTEN about being given notice about the water bill and non payment affecting your ability to renew a lease. There should be something IN WRITING stating that this would take place either immediately (as in you would not be able to renew, evicted, or you would be given a warning).
Someone else may be able to add to what I've written here. I believe firmly in "where there is a will there is a way" and in this case....your manager just gave you some more ammunition to find another way!
I hope this might help you in some way.