A French drain is a trench filled with gravel or rock and contains a perforated pipe that redirects surface or groundwater away from specific areas. Often lined with landscaping fabric to prevent clogging, the pipe helps carry water to a better drainage area, such as a storm drain, dry well, or a low point in the yard. https://texasgardenmaterials.com/landscape-design-houston-tx/french-drain-installation-houston-tx/