A sump pump is a submersible pump that sits at the bottom of a sump pit, which is typically installed at the lowest point in your basement or crawl space. Ground water surrounding your home's foundation is channeled into a perimeter drain system installed at the base of the foundation.
Water finds its way into the perforated drainpipes and is quickly diverted to the sump pit. The sump pump, which is triggered by a float switch, removes the water by pumping it to the nearest storm drain, dry well or detention pond. A sump pump turns on only when water inside the sump pit reaches a pre-determined level.