Drain Pipe Installation & Water Flow

What happens here

The presenter explains the complete water flow within this integrated system. When precipitation occurs, water will first hit the planting soil, gradually saturating it. The excess water will then trickle down through the permeable geotextile fabric. From there, it will pass efficiently through the coarse drainstone layer. At the very base of this drainstone layer, a perforated drain pipe, typically a black corrugated pipe, is installed. This pipe is designed with small holes to collect all the water that has percolated through the upper layers. It then channels this collected water outwards, away from the retaining wall and the patio structure, usually to a lower grade, a storm drain system, or a designated discharge point. The video visually demonstrates this black corrugated perforated drain pipe extending through the retaining wall structure.

Goal: Install a perforated drain pipe to efficiently remove collected water from behind the wall.