In the absence of a specific servitude entitling your neighbour to dump his water onto you, your first port of call must be the local municipal regulations. These differ from one local authority to another – so you must check what applies in your particular area - but as a general principle, they will probably provide for something along these lines:
- All owners must discharge their storm water onto a public street wherever practicable;
- Only where that is impractical, must you accept water from a higher property (in which event, you can probably recover from your neighbour the cost of any necessary drain or pipeline);
- Alternatively, some municipalities have carte blanche to give directions as they see fit to private owners, e.g. to direct you to allow your neighbour to construct a drain over your property.
Whilst the general rule in our common law is that water has to be accepted by a lower-lying property from a higher-lying property, a recent Supreme Court of Appeal decision demonstrates that – at least in heavily-developed urban areas – this rule will seldom have any practical application. This is because of one very important proviso, namely that you are only obliged to accept the “natural flow” of water. You do not have to accept any increased flow (nor any “concentration” of the flow) resulting from development of the higher property, i.e. landscaping, erection of buildings, paved areas, walls etc.
Critically, the Court held that the onus is on the owner of the higher property to prove what constitutes the “natural flow” of the water, and in practice this is likely to be an impossibly complex task. As the Court commented, “determination of the ‘natural flow’ in the urban context is rendered virtually impossible by the very establishment of a modern urban township”.
So (unless we are talking about a flow of water that demonstrably existed on the property in its “natural state”), the problem is probably your neighbour’s – ask him/her to deal with it, and get legal assistance if that fails.