Natural overland flow
Natural overland flow between private properties occurs when the land is sloping between the properties. Natural overland flow is the water flow path before any excavation, development or building on the land. Ideally, overland flow should be directed towards the street or a drainage system (lawful point of discharge), where available.
Property owners are required to accept natural overland flow from adjoining properties or public land. An upstream property owner cannot be held liable merely because overland surface water flows naturally from his/her land on to the lower land of a neighbour. However the upstream property owner may be liable if actions they undertake result in increased or more concentrated flows than would normally be naturally occurring.