Water always flows downhill, and by the easiest route possible. That’s the basic concept behind a French drain, a slightly sloped trench filled with round gravel and a pipe that diverts water away from your house.
French drains provide an easy channel for water to flow through. Water runs into a gravel-filled trench, then into perforated pipe at the bottom of the trench.
Water travels freely through the pipe, which empties a safe distance from the house.