Sump pumps are the best defense against basement (or crawlspace!) flooding. Along with a perimeter drainage system, a sump pump collects and directs water out of your below-grade space. Following flooding or heavy rain, a pressure sensor signals that water has exceeded a certain level. This triggers the sump pump, which sends the water to the perimeter drainage system. The drainage system empties out the water a few feet from your home's foundation.
Encapsulation is the best way to keep crawlspaces dry, sanitary, and safe. Unencapsulated crawlspaces are vulnerable to moisture, mold, mildew, and pests. Moisture leads to mold, which attracts pests and creates disgusting smells that bother upstairs residents. As pests gather in the area, they eventually die, attracting even more critters. Moisture and mold also beget rot, which destroys wooden beams and joists that support the rest of the home. An encapsulation system protects against these dangers. A properly encapsulated crawlspace also provides extra storage space!