Useable? Well...it won't be filled with sewage, presumably (we're going to have to scrub it down with a bleach and water solution sometime soon). I don't expect that we'll be having lunch or hanging out down there, though. After all, it IS an unfinished basement.

As for drainage, that wasn't really the problem; I don't think that the basement has EVER flooded because of rain, for example. The problem was that the roots sometimes blocked the main line, and all wastewater simply backed up and flooded the basement.

There's no chance of that happening now, though. It's all new pipe.

You know, I'm pretty sure that the pipe was broken long before we bought the place. Yet another reason to be angry at the previous owners.