Toronto & the GTA
Do You Need a Backflow Preventer for a Sprinkler System in Ontario?
Yes. Under the Ontario Building Code, a lawn irrigation system connected to the drinking-water supply must have an approved backflow preventer, so water from the sprinkler lines can never flow back into your home's water. Some municipalities also require the device to be tested by a certified tester.
Updated
What is backflow?
Backflow happens when water flows the wrong way, from the sprinkler lines back into your house plumbing. A sudden drop in city water pressure, for example during a watermain break, can pull water out of the irrigation pipes, and that water can carry fertilizer, soil and bacteria.
Common types of backflow preventer for irrigation
The right device depends on your connection, the height of the sprinklers and local rules. The types used on lawn irrigation include:
- Pressure vacuum breaker (PVB), installed above the highest sprinkler head
- Double check valve assembly (DCVA)
- Reduced pressure principle assembly (RP), the highest level of protection
Does it need to be tested?
Testable devices may have to be checked by a certified backflow tester, often when installed and then on a regular schedule. Requirements vary by municipality, so we confirm what applies to your address.
Winter care
The backflow preventer is often the most exposed part of the system. It is drained and checked during every HigreenWall fall closing so it does not freeze and crack.
Is it included in your estimate?
Our online calculator does not include the backflow preventer, because the right device depends on your water connection. We confirm it at the free site visit and quote it separately.