For convenience, drainage grooves and a drainage plane can be integrated into the stone surfaces at the sink so that, when rinsing, dishes can be placed at the sink and the water drains into the sink as it dries. Grooves are made on one side or the other of the sink, usually 5 grooves about ~400mm long with or without a recess. It is essential that the groove and drainage recess are at an angle to the sink to fulfil its function and allow water to drain.

The milling of good quality and functional swales and drainage recesses is a technically demanding process, which is carried out with appropriate equipment. It is important that the recess and grooves fulfil their function and are not a decorative feature where water accumulates.