A French drain is a type of drainage system that is designed to redirect water away from a particular area. It is typically installed underground and consists of a perforated pipe that is surrounded by gravel or other porous material, which allows water to filter into the pipe and be carried away.
French drains are commonly used to prevent water from entering basements or other below-ground areas, as well as to control erosion on hillsides or other sloping terrain. They can also be used to redirect surface water away from buildings and other structures, or to control standing water in low-lying areas.
The name "French drain" comes from the fact that the system was first popularized by a 19th-century farmer named Henry French, who used it to improve agricultural drainage on his property. Today, French drains are commonly used in residential, commercial, and industrial settings to manage water runoff and prevent water damage.