My neighbour's new well is affecting my water supply on our Ontario rural property — what can I do?

Groundwater rights in Ontario are not privately owned in the way that surface land is — groundwater is generally a public resource regulated by the province. Under the Ontario Water Resources Act, any person who takes more than a prescribed amount of water from a well must hold a Permit to Take Water issued by the Ministry of the Environment, Conservation and Parks. Smaller domestic wells (for a single household) are typically exempt from the permit requirement.

If a neighbour's new well is drawing down the water table and affecting your well's yield, you may have several options. First, report the issue to the ministry. If the neighbour's well required a permit and the permit conditions are being violated, the ministry has enforcement authority. Even for non-permitted wells, the ministry may investigate significant interference with domestic water supplies.

At common law, the traditional rule was that landowners could draw groundwater freely under their property, which limited nuisance claims based on groundwater interference. However, case law has evolved, and if a neighbour's pumping causes unreasonable interference with your water supply through negligence or malicious action, a claim may be available.

Practical remedies may also include deepening your own well, installing a pump to restore supply, or negotiating a water-sharing arrangement. Speak with a lawyer and, if needed, a hydrogeologist to understand the technical and legal dimensions of the issue.