French drains are a type of drainage pipe that is used in areas where the water table is high. They are installed in order to prevent flooding in homes and buildings. French drains can be installed for many reasons. They can be installed to prevent water from entering a basement, drain water from a specific area, or collect rainwater from an area where it cannot drain freely on its own. French drains end in an open ditch or sewer system, but some have the ability to discharge into dry wells or septic tanks.