Abstract: A drainage system for removing groundwater from underneath a water impervious surface including a first housing located below grade having a continuous sidewall, a floor, an open top extending to or through the surface through which stormwater collecting on the surface may enter into the housing, an outlet extending through the sidewall immediately adjacent to the floor and an inlet through the sidewall. A locking ring is fixed within the inlet, and a drain wick is coupled to the locking ring, the drain wick being configured for collecting groundwater underneath the surface and directing the groundwater through the inlet and into the housing. The drain wick includes a pipe having and plurality of radial openings, a perforated first end cap, a second end including screen and a locking nut configured for coupling to the locking ring and a filter bag located between the screen and end cap.