Abstract: A drainage system located adjacent a pavement subbase includes a tube of a geotextile fabric supported by a self-sustaining water-porous plastic support. An end of the fabric tube and its encased support are compressively received in the flared open end of an outlet connected to a conventional drainpipe. The outlet includes a plurality of projections which trap the fabric tube between the support and the outlet, so as to securely retain it therein. The outlet also preferably includes a plurality of circular beads over which the corrugated drain tube can be frictionally slipped. Alternatively, the outlet can be configured as a flat union of T-shaped junction joining one or more upstream fabric tube-and-support filters with a downstream outlet constructed from an identical fabric tube and support.