Ha, you got me. I'm pretty sure there's no leaks at this point, but I'm leaving that space behind the toilet open because...I'm waiting to be inspired by a clever use of that dead space. I was thinking of build a small storage area (maybe for toilet paper or whatever) that could also be tall enough to act as a small shelf behind the toilet.

An excess of ideas is what stops me from completing any project. Once you officially complete it then all those little pending ideas have nowhere to go.