Stopping a Neighbour's Ongoing Flooding Before Another Storm

The situation

Quang worked as a line cook and Genevieve as an early childhood educator, and together they owned a modest semi-detached home in London that they had spent three years slowly renovating, most recently finishing the basement into a playroom for their toddler. Next door, their neighbour Micheline ran a small landscaping and interlocking contracting business out of her house, storing equipment, gravel and topsoil in her backyard between jobs.

Over one winter, Micheline regraded her property to improve drainage around her own equipment storage area. She raised the level of her yard along the shared property line and installed a short retaining wall, but did nothing to redirect the water that used to soak into her lawn. That water now had only one place to go: downhill, onto Quang and Genevieve's side, and toward their basement window wells. Neither of them had any background in construction or drainage, and for weeks neither of them realized the change next door was the cause — they assumed their own eavestroughs were to blame, and Quang spent a Saturday re-sloping the splash blocks under their own downspouts before the second flood made clear the problem was coming from higher ground, not their own roofline.

The first flood came with a heavy spring rain. Water pooled against their foundation, seeped through a window well, and soaked about a third of their finished basement, ruining a section of laminate flooring and the drywall behind the new playroom shelving. They cleaned it up, assumed it was a one-time event, and mentioned it to Micheline, who was polite but noncommittal about the grading. Five weeks later, after the next significant rainfall, it happened again — worse this time, reaching further into the room and soaking the underside of the drywall along an entire wall.

The legal problem

By the time Quang and Genevieve came to us, they had already sent Micheline a written request asking her to restore the grading or add drainage to stop the water crossing onto their land. She did not respond. Meanwhile, a contractor's report they commissioned estimated repair costs at around $14,500 for waterproofing, drywall replacement and flooring, and forecast a real risk of mould if a third flood occurred before the underlying cause was fixed.

This is a nuisance problem under Ontario's common law: a property owner who alters their land in a way that causes water, debris or other harm to flow onto a neighbour's property can be liable for the damage that results, even without any intent to cause harm. The available remedies are damages to compensate for what has already happened, and an injunction — a court order requiring the responsible party to stop the harmful conduct or to take steps to correct it.

The challenge was timing. Waiting for a full trial, which can take a year or more from start to finish, meant Quang and Genevieve would likely face at least one more flood season with the grading unchanged. A claim for damages alone, filed in Small Claims Court where claims up to a set monetary limit are heard, would not compel Micheline to fix the grading at all — Small Claims Court can order a defendant to pay money, but it cannot order someone to change how they use their land. Getting the water stopped required an injunction, which only the Superior Court can grant, filed on an urgent basis before the next major rainfall.

What we did

1. Documented the pattern before moving. We worked with Quang and Genevieve to assemble photographs from both flood events, the contractor's damage report, rainfall records for the two dates in question, and photographs of the regraded yard showing the water's path. A court asked to grant urgent relief needs to see a clear, provable pattern, not just one bad afternoon.
2. Filed for an interlocutory injunction in the Superior Court. This is a temporary order made before a case is fully resolved, meant to preserve the situation and prevent further harm while the underlying dispute is litigated. We paired it with a claim for damages to cover the repair costs already incurred, so both problems — the ongoing risk and the past harm — were addressed in the same proceeding.
3. Argued the three-part test courts apply to injunctions. A party seeking this kind of order generally has to show there is a serious legal issue to be tried, that they will suffer harm that cannot adequately be fixed with money alone if the order is refused, and that granting the order causes less hardship overall than refusing it. We argued that repeated flooding of a finished basement, with a real mould risk building each time it recurred, was exactly the kind of ongoing, compounding harm that damages after the fact could not properly undo — Quang and Genevieve would be litigating for a year while their basement kept flooding.
4. Requested the application be heard on short notice. Because a forecasted rain system was approaching within the following two weeks, we asked the court to hear the matter urgently rather than on the usual timeline, giving Micheline's side a shortened but fair opportunity to respond before the next storm arrived.
5. Negotiated the terms of compliance once the order was granted. An injunction that simply says the flooding must stop, without specifics, invites more disputes about what compliance means. We worked out concrete terms with Micheline's lawyer: a swale and grading correction along the property line, installed within a defined window, with a follow-up inspection to confirm the work matched what was ordered.

The outcome

The court granted the interlocutory injunction, ordering Micheline to stop directing surface water onto Quang and Genevieve's property and to correct the grading along the shared line within a set period. The forecasted storm arrived before the corrective work was finished, but the temporary measures Micheline put in place under the order — sandbagging and a temporary diversion channel — held, and no third flood occurred.

With the immediate risk contained, the damages claim settled rather than going to a full trial. Micheline's insurer ultimately paid Quang and Genevieve about $16,800 toward the repair costs and the increased home insurance premium they had absorbed after filing two flood-related claims in one year. That figure covered the bulk of the $14,500 repair estimate plus roughly $2,300 in related costs, short of their full original claim of about $19,000 once minor items were negotiated down, which is a typical outcome when a case resolves by settlement rather than a judge's award after trial. Neither side wanted to spend another year in the Superior Court arguing over the last few thousand dollars once the drainage itself was fixed, and the settlement let both households move on before the following spring's rains arrived.

The corrected grading was inspected and confirmed compliant, and the interlocutory injunction was later converted into a permanent order by consent, meaning Micheline agreed to make the drainage fix a lasting condition rather than litigating the point further. Two full rainy seasons have passed since without incident, and Quang and Genevieve were able to finish rebuilding the playroom without wondering whether the next storm would undo the work again.

What you can learn from this