Neighbouring properties are often the cause of residential and rural flooding. Flooding can arise through insufficient culverts, improper diversions of water, or interference with drainage or absorption of water from/by their land. Often there is a distinction between surface waters and waters flow in a defined channel, though in practice, liability is often attributed in a similar fashion.
The law in Canada has consistently been that an upper landowner is not liable to a lower landowner from damage caused by the natural flow of surface water or water percolating through the ground. The exception here is where the upper landowner has altered or interfered with the natural flow of the surface water or percolating water. This can be done by changing the topography, changing the permeability of the surface (e.g. asphalt), or other changes that negatively impact lower lands. With these changes, the upper landowner must take all reasonable steps to prevent injury to neighbouring lands.
The same can be said for lower landowners. It is clear that lower landowners have a right to block surface waters coming onto their property from upper lands. But this right is again tempered by reasonableness such that the lower landowner must use reasonable care and skill and do no more than is reasonably necessary to protect their land.
There is also an important distinction between surface water and a natural watercourse. A natural watercourse is a definite channel with banks or sides with a bottom or bed where water runs seasonally or all year round. In instances where a person interferes with or makes changes to a natural watercourse, they will often be held liable to the extent those changes were insufficient to handle the flow of the watercourse, even where damage was cause to property not directly bordering the watercourse. Here, even natural events or extraordinary rainfall won't be enough to negate liability.
If you think your flooding issues result from someone else's actions, talk to your insurance provider. If, like in most instances, insurance doesn't cover your loss, talk to a lawyer. Our lawyers at Merovitz Potechin LLP are ready and willing to help those impacted by any type of flooding, large or small.