Abstract: An improved culvert drainpipe and method of utilizing the same is disclosed characterized by use of an elongate thin wall extruded drainpipe element formed having a generally S-shaped configuration defining a pair of main flow channels and including plural curvilinear projections extending axially along the exterior of the element. The distal edges of the drainpipe element cooperate with one or more elongate wall extensions formed on the interior of the drainpipe element which prevent radial compression and/or collapse of the drainpipe element and deter debris from entering into the main the flow channels. In use, multiple drainpipe elements are bundled together in a generally parallel axis orientation whereby the curvilinear projections serve as secondary flow channels, improve debris segregation, and maintain space between adjacent drainpipe elements.