Aquadrain 18H drainage composite is a two part prefabricated sheet drain consisting of a 3-dimensional polypropylene formed dimple core covered with a heavy 8-oz. nonwoven polypropylene filter fabric on one side. The formed dimple core provides compressive strength and collects water for flow to drainage discharge pipes. Aquadrain 18H drainage allows water or other liquids to pass into the drainage core while restricting the passage of soil particles. It is bonded to each dimple to minimize fabric intrusion into the core resulting from backfill pressure. The polypropylene core resists chemical attack and degradation in soil.