Originally Posted By: MNgopher
What isn't clear to me now is whether you have one outlet from your home that carries everything to the combined sewer (ie: your sump, sanitary, and gutter drainage) or if you have two lines - one for sanitary (which in most of the country would include your floor drain), and another for your sump and gutter discharge.
Either way, if your system is full, that means there is a clog/break/or blockage downstream from your cleanouts that needs to be addressed. It is possible the "blockage" is the system being overwhelmed and over capacity and your basement is the relief valve, in which case too bad for you, and you need a backflow preventer (though that only keeps water from backing in - if you add water on your side, it won't have anywhere to go, and will probably pop out your floor drain).
Regardless, start pulling the drywall out, get the fans going along with a dehumidifier, and get a plumber to sort out the drain issue. If you've had to have the line rodded twice in the past year, odds are you are in for a full line replacement, this being the third time you've needed this service.
If your sump pump and gutters didn't tie into your main line (or had another way out), you'd have way less water in your basement. While not the cause of your problem - they didn't help.
It's not clear to me either. I have ONE main line out to the street. Where they combine, I'm not sure.
I also completely agree that if the gutters didn't tie in the main, I'd have little to no water...