Abstract: Void-maintaining geocomposite laminates, and drainage systems utilizing those laminates, are provided for location below a road surface or below a large structure such as a building, retaining wall or parking lot. The laminates include at least one fluid-transmissible layer adjacent an upper or lower surface of a polymer-based core. Optionally, another fluid-transmissible layer is provided adjacent a lower surface of the polymer-based core to form geocomposite laminates having high permittivity and high transmissivity. The one or more fluid-transmissible layers are preferably geotextiles. Characteristic of the core element is high transmissivity, that is, a high rate of horizontal flow of gases or liquids through the core. Characteristic of the at least one fluid-transmissible layer is high permittivity, that is, a high rate of vertical transmission of liquids and gases through the geotextile layer and into the core element.