Boulevard Trees in Calgary: Who's Responsible?

That big elm or ash tree between your sidewalk and the curb — it shades your front yard, drops leaves on your lawn, and occasionally sends a root into your sewer line. But who actually owns it? Who is responsible for maintaining it? And what happens if you want it removed? Boulevard trees in Calgary exist in a grey area that confuses many homeowners. Here is how it actually works.

The City Owns Boulevard Trees

In Calgary, the strip of land between the sidewalk and the street — the boulevard — is city property. Trees planted on this strip are owned and managed by the City of Calgary's Urban Forestry department. This applies even if you or a previous owner originally planted the tree. Once it is on city land, it is a city tree.

The city's urban forest inventory includes roughly 7 million trees on public land, including boulevard trees, park trees, and trees along pathways. Boulevard trees make up a significant portion of this inventory, especially in established neighbourhoods where they were planted decades ago and have grown to full maturity.

What the City Is Responsible For

As the owner, the City of Calgary is responsible for:

• Pruning: The city prunes boulevard trees on a cyclical basis, typically every seven to ten years depending on the neighbourhood and species. Pruning focuses on structural health, clearance over sidewalks and streets, and sight-line maintenance at intersections.
• Removal: If a boulevard tree is dead, dying, or hazardous, the city will remove it. Residents can report problem trees through the 311 app or by calling 311.
• Replacement: When a boulevard tree is removed, the city generally replaces it with a new tree, though there may be a waiting period depending on planting schedules and available stock.
• Storm damage: If a boulevard tree is damaged in a storm, the city handles the cleanup and any necessary removal.

What You Cannot Do

Because boulevard trees are city property, there are important restrictions on what homeowners can do:

• You cannot remove a boulevard tree. Even if the tree is causing problems — root intrusion, excessive shade, sidewalk heaving — you cannot remove it without the city's authorization. Unauthorized removal of a city tree can result in fines and a requirement to pay for a replacement.
• You cannot prune a boulevard tree. Technically, any pruning of a city tree requires authorization. In practice, the city does not usually object to homeowners removing small deadwood or trimming minor branches, but any significant pruning should be requested through the city.
• You cannot apply chemicals. Spraying pesticides, herbicides, or any chemical treatment on a boulevard tree without city approval is not permitted.

What You Can Do

While your options are limited, you are not powerless:

• Report issues: If a boulevard tree is dead, damaged, leaning, or has large dead branches, report it through Calgary's 311 service. The city will schedule an inspection.
• Request pruning: If a boulevard tree's branches are interfering with your property — blocking a window, rubbing against your roof, or hanging low over your driveway — you can request a pruning visit through 311.
• Water and mulch: Caring for the tree's health is encouraged. Watering a boulevard tree during dry periods, especially newly planted ones, helps it establish and thrive. You can apply mulch around the base, following proper technique (flat ring, not volcano).
• Request removal for cause: If you believe a boulevard tree poses a genuine hazard or is causing demonstrable damage (such as root intrusion into your sewer line), you can submit a request for the city to assess it. If the city agrees the tree needs to be removed, they will handle it.

The Sewer Line Question

One of the most common complaints about boulevard trees is root intrusion into sewer lines. Older Calgary neighbourhoods with clay sewer pipes are particularly vulnerable — tree roots seek out the moisture and nutrients in sewer lines and enter through joints and cracks. The city generally takes the position that the roots follow existing pipe defects rather than causing them, which means the homeowner is typically responsible for sewer line repairs even when boulevard tree roots are the immediate cause.

If you are dealing with recurring sewer backups from boulevard tree roots, the most effective long-term solution is usually relining or replacing the sewer lateral from your house to the main. Root cutting and chemical root treatment are temporary fixes that require repeated application.

Trees on Property Lines

Boulevard trees should not be confused with trees on or near property lines between neighbours. Those follow different rules. In Alberta, if a tree's trunk is entirely on your neighbour's property, the tree belongs to them. You have the right to trim branches and roots that cross onto your property, but only up to the property line. It is good practice to discuss significant trimming with your neighbour first, both for relationship reasons and because aggressive root cutting on one side can destabilize the tree.

Getting the Best Outcome

If you have a boulevard tree that is causing problems, patience and persistence through the city's reporting system is the most effective approach. Document the issue with photos, submit a 311 request, and follow up if you do not hear back within a reasonable timeframe. The city's urban forestry staff are generally responsive, but they manage hundreds of thousands of trees with limited resources, so prioritization is based on safety risk.

For trees on your own private property, you have full authority to prune, treat, or remove as needed — and an arborist can help you make the right call.