Your finished basement may very well be your pride and joy. You’ve probably spent thousands of dollars and a lot of time converting your concrete foundation into customized living space. You probably don't want a tidal wave of ground water or sewage making it's way into your new finished space. A flash flood, a cresting river or creek, or a simple summer tropical storm can potentially turn your new carpeting and dry-wall into a giant mold fest. Your finished basement isn't really finished, unless you have taken some of these flood prevention steps to protect it in the future.