1.1 ,This specification covers geocomposite drainage panels used in highway, turf, and other high-volume subsurface drainage applications. These products consist of a geotextile wrapped around a polymer core. These products are a minimum of 25 mm (1 in.) thick and are available in 150-mm (6 ,in.), 300-mm (12 in.), 450-mm (18 in.), and 600-mm (24 in.) widths.