What is the primary purpose of a French drain?

The primary purpose of a French drain is to redirect surface water and groundwater. This type of drainage system is specifically designed to alleviate excess water from areas that are prone to flooding or saturation. By using a trench filled with gravel or rock containing a perforated pipe, the French drain allows water to flow through it and away from foundations or other sensitive areas, effectively managing water drainage.

This system helps to prevent water accumulation and can protect the integrity of structures by reducing hydrostatic pressure against foundations. It is particularly useful in landscapes where gravity can carry water away from problem areas toward a designated drainage outlet. The effective redirection of both surface runoff and subsurface water is a critical aspect of maintaining dry, stable land and preventing water-related damage.