Most often a homeowner can look into the crawl space and see a dry dirty environment. However, it does not mean that is the all year condition of the space. When weather events, like flash floods, extended heavy rain storms, post landfall hurricanes, and early snow melts can cause a normally dry crawl space to be several inches if not feet under water for extended periods of time. There are signs of these events in your crawl space.
1) Look for water lines on the foundation wall
3) Soft Wet Dirt
Don't forget to download the crawl space encapsulation checklist to make your project go as smooth as possible.