A drainage tube includes alternating annular peaks and annular valleys on an exterior wall of the tube. An interior wall of the tube is smooth and continuous along its length. The combined exterior wall and interior wall form an elongated tube. In alternating, selected valleys of the exterior wall of the tube are arranged a plurality of slots extending transverse to a longitudinal axis of the tube so that water can drain into the tube through the slots. These plurality of openings extend through the smooth interior wall of the tube to the interior space of the tube. In addition, each of the annular peaks on the exterior wall of the tube includes a recessed groove. At the base of each of these grooves are located a plurality of circular openings having a smaller diameter on the exterior of the tube, increasing in diameter towards the interior of the tube. Corresponding openings are located on the smooth interior wall of the tube so that water can drain into the tube through these additional openings located spaced from the openings in the grooves of the annular peaks of the exterior wall.