A French Drain, also known as an Interior PRS (Pressure Relief System) is an important waterproofing solution. A PRS relieves the water pressure on exterior walls by allowing the water to drain in through the wall and into the system, where it can be collected and ultimately pumped out of the basement. This involves installing a perimeter drain on the interior of the basement. A section of the floor around the perimeter is dug out, an underground piping system surrounded by crushed stone is installed, then concrete is used to cover the area. All the underground piping is then diverted into an interior sump basin where the water is then pumped into a sewer line or to the exterior far from the house. These systems can be installed either in the full perimeter or partially around the basement, depending on your needs.