It also is widely used in parking lots and similar locations to remove sheet flow without complex multiple grades, catch basins, or water channeling devices. Slotted Drain Pipe is a practical, aesthetically pleasing drainage inlet product for the efficient removal of surface water and sheet flow on streets and highways. Western Corrugated Steel Pipe Association (WCSPA).Southeastern Corrugated Steel Pipe Association (SECSPA).Great Lakes Corrugated Steel Pipe Association (GLCSPA).NCSPA Education & Research Institute (NERI).
