Sump pumps move water from low parts of a basement or crawlspace. www.MrHardware.com
The pump keeps the under-building dry, and prevents the area from flooding. Usually installed in a sump pit, the water flows into the sump pit through drain tiles or naturally through the soil. Some suck water off a shallow surface of cement or dirt. The pump switches on at a certain water level and switches off again when the lower water drops. The water moves up the pipes, and out away from the building not to return.