What Counts as a Trigger Depth for Snow Removal?

3 min read · Thames Valley Snow, London, Ontario

Trigger depth is one of the most important terms in a snow removal contract, yet it's rarely explained clearly. In simple terms, it's the amount of snowfall that has to accumulate before your snow removal company automatically dispatches a crew to clear your property. Understanding this number changes how you experience every storm all winter long.

Most seasonal contracts set the trigger depth somewhere between two and five centimetres. A lower trigger, like two centimetres, means crews come out more often, even for light dustings, keeping your driveway consistently clear but potentially costing more in labour over the season. A higher trigger, like five centimetres, means fewer visits but the possibility of a thin layer of snow sitting on your driveway for a few hours before a crew shows up.

The right trigger depth depends on what you actually need. Someone who leaves for work at 6 a.m. every day probably wants a lower trigger so their driveway is reliably clear no matter how light the overnight snowfall was. A retiree who works from home might be fine with a higher trigger and less frequent visits, since a light dusting isn't a real obstacle for them.

It's worth asking your provider how they measure trigger depth too. Some use official Environment Canada snowfall totals for the region, others measure on-site at your property, which can matter during localized lake-effect bursts that hit some parts of London harder than others.

Thames Valley Snow sets trigger depth with each homeowner individually rather than applying one blanket number to every property, because a family with an early commute has different needs than a retired couple working from home. Knowing your trigger depth before the season starts means no surprises when the first flakes fall.

Thames Valley Snow trigger

Residential seasonal visits are automatic at 5 cm or more. In long storms, the crew returns so snow does not build too deep before it is cleared.

Commercial triggers

Commercial contracts set the trigger in writing. Many sites choose a lower trigger for sidewalks and entrances than for the lot, and some add per-event salting. The trigger and the opening time both shape the price.

Ice without snow

Freezing rain and refreeze can be dangerous with no snowfall at all. Seasonal salting ($175) includes freezing rain and refreeze visits.

Frequently asked questions

Who decides if the trigger was reached?

The crew goes by snowfall in your area and conditions on site.

Can I choose a lower trigger?

For commercial sites, yes, it is set in the contract. For residential, ask the team.

What's included… and what's extra

A Thames Valley Snow seasonal residential plan starts from $650 for a standard driveway. It covers clearing the driveway every time snowfall reaches the trigger depth in your agreement, plus the windrow the city plow leaves at the end of the driveway. Larger driveways are priced on our snow removal prices page.

Popular add-ons, priced per season: walkway and steps $150–175, salting $175, priority service $125, pet-safe salt $120, driveway extension $95 and city sidewalk clearing $90. Add only what your property needs; everything is listed on the quote so there are no surprises. Get your fixed price or call or text (548) 888-8702.