What Is a Trigger Depth in a Snow Removal Contract?

Quick answer

• What it is: the snowfall depth that starts a plowing or clearing visit.
• What it sets: when you must respond, and when you can bill.
• What it needs: a unit (cm or inches), where it is measured, and what counts if you disagree.
• What it doesn’t cover: ice. De-icing needs its own trigger, because ice can form on nights with no snow.
• There is no standard number. It is whatever you and the client agree and write down.

How to choose the number

• Lower for busy surfaces. You can set a lower trigger for walks, entrances and ramps than for the parking lot, because people walk there first.
• “Any snow” is a trigger too. Some clients want service at any accumulation. Price it for the extra visits it brings.
• Match your capacity. A lower trigger means more visits in a light storm. Make sure your crews can reach every site that triggers at once.
• Price it in. Per-event prices and seasonal prices both depend on how many visits the trigger produces. The free pricing calculator asks for it.

Where and how it is measured

1. Where: an undisturbed spot on the site, not a drift, a pile or a sheltered corner. Name it if the site is big.
2. What counts: new snow since it started falling, or since your last visit, on the surface you service.
3. How: a ruler or a marked stake, with a time-stamped photo of the reading when it matters.
4. If you disagree: name a weather source in the contract, such as an Environment and Climate Change Canada or U.S. National Weather Service station near the site.

De-icing needs its own trigger

Snow depth says nothing about ice. Freezing rain, refreeze after a thaw and a clear, cold night after a melt can all need salt with no snow to plow. Write a separate de-icing trigger, based on conditions such as ice, freezing rain or a pavement temperature you name, and treat each de-icing visit as its own event, with its own rate on a per-event contract.

A snowfall usually brings both: a plowing visit at the trigger, then a de-icing visit. They are two events. On a per-event contract that prices de-icing separately, each is its own line on the invoice; if your contract includes de-icing with the plowing visit, say so in writing, so the client is never billed twice for one storm.

Wording you can adapt

“Plowing starts when [5 cm / 2 in] of new snow has accumulated on the parking lot, measured at [location]. Walks and entrances are cleared at [2.5 cm / 1 in]. De-icing is a separate visit, started by [ice, freezing rain or refreeze]. Where depth is disputed, the [named weather station] record for the site’s area applies. Service begins within [response time] of the trigger.”

Pair it with a definition of when an event ends, so a storm with a lull is billed the same way every time. Per-event billing explained covers that sentence, and the contract clauses guide covers the rest of the contract. Have a local lawyer review the final wording.

Arguments a clear trigger prevents

• “You plowed a dusting and billed us for it.”
• “It snowed and nobody came.”
• “That was one storm, not two.”
• “The walks were icy but you only plowed.”

Setting your triggers in Icey Software

We make Icey Software. In Settings → How you work → Triggers & season, you set your snow trigger, in centimetres or inches to match your units, and your de-icing temperature trigger, along with your response time. Your quotes and contracts print what you enter there; leave a trigger blank and your documents make no promise about it.

Weather Center has a “Notify me” alert you can switch on for when the forecast crosses your snowfall trigger. Free forever up to 10 sites and 5 crew. Every feature.