Two scuppers cut into either side of this outdoor stairwell prevent water from building up and making the stairs slippery.
A scupper is an opening in the side walls of a vessel or an open-air structure, that allows water to drain instead of pooling within the bulwark or gunwales (of a vessel), or curbing or walls (of a building).
Ship's bulwark and scupper. The scupper hole (8) has a grille cover, with water leading through the scupper pipe (9) to an outlet (10)
There are two main kinds of scuppers:
Ships have scuppers at deck level, to allow for ocean or rainwater drain off.
Buildings with railed rooftops can construct scuppers to let rainwater drain off, instead of pooling within the railing of the roof. Scuppers can also be placed in a parapet, for the same purpose.