An extruded high-density polyethylene (HDPE) drainage core is combined with a non-woven filter fabric that is bonded to the ridges of the geonet. The filter fabric effectively traps soil or sand particles, as well as freshly placed concrete or grout, while allowing filtered water to flow through to irregular surfaces. Due to its crush-resistant properties, geonet drainage composites are ideal for use in demanding applications, including areas subjected to heavy loads or vehicular traffic, both horizontally and vertically.