Can My Neighbour Dig Up or Change the Grade Next to My Property and Flood My Yard in Ontario?

Re-grading that sends water onto your lot can be a problem, and the answer depends on the facts. Under Ontario common law, collected or discharged surface water, such as roof runoff, must not be diverted onto land that would not naturally receive it, or liability for damages can follow. The exception is a prescriptive drainage right, which may arise from 20 years of continuous, open, peaceful, uncontested use without permission, but a court must confirm it and it can be lost if the drainage is increased.

Your municipality may also regulate this. A local municipality may prohibit or regulate the placing or dumping of fill, the removal of topsoil and changes to the grade of land, and may require permits and impose permit conditions. Some activities are exempt, such as activities by a municipality or drain construction under the Drainage Act. Complaint channels vary, so start with your municipality.

If water is damaging your property, a court that can grant an injunction may award damages in addition to or instead of it. Money claims up to $50,000 can go to Small Claims Court, and the basic limitation period is two years from the day the claim was discovered.