The above-ground system of gutters and rainwater pipes is referred to as roof drainage; the underground pipework is referred to as surface water drains and surface water sewers.
Cyfeirir at y systemau o gwteri a phibelli dŵr glaw uwchben y ddaear fel draenio toeau; cyfeirir at y pibelli o dan y ddaear fel draeniau dŵr wyneb a charthffosiaeth dŵr wyneb.