What's Ottawa's tree protection bylaw saying about my driveway?

Ottawa's tree protection bylaw can significantly impact driveway projects, especially if you're planning to widen, relocate, or install a new driveway near existing trees. The City of Ottawa Tree Protection By-law (2009-200) requires permits for removing or injuring trees over certain sizes and establishes protection zones that can restrict driveway work.

Key bylaw requirements include needing a permit to remove any tree with a diameter of 10 cm or larger (measured 1.4 metres above ground), and this applies to trees on both private property and city property. For driveway projects, this becomes critical because many Ottawa homes have mature maples, oaks, or ash trees near existing driveways that homeowners want to widen or reconfigure. The bylaw also prohibits damaging tree roots within the "critical root zone" — typically extending 10 to 12 times the tree's diameter from the trunk.

Driveway-specific implications are substantial in Ottawa's established neighbourhoods. If your driveway expansion requires removing a protected tree, you'll need a tree removal permit from the City (currently $50 plus replacement requirements). More commonly, driveway work near existing trees can damage critical roots even without removing the tree itself. Excavating for new base material, trenching for drainage, or operating heavy equipment within the critical root zone can severely damage or kill trees, potentially resulting in bylaw violations and fines up to $100,000 for destroying distinctive trees.

Replacement requirements are expensive and mandatory. The bylaw requires replacing removed trees with new plantings of equivalent ecological value — often meaning multiple smaller trees for each large tree removed. In heritage districts like the Glebe or Westboro, replacement requirements can be even more stringent. Some homeowners discover that the cost of tree removal permits, replacement plantings, and landscape restoration exceeds the cost of the driveway work itself.

Practical planning steps include having a certified arborist assess any trees within 15 metres of your planned driveway work before getting contractor quotes. The arborist can identify which trees are protected under the bylaw, map critical root zones, and recommend construction methods that minimize root damage. Many paving contractors in Ottawa work with arborists regularly and can suggest root-friendly excavation techniques like hand digging near trees or installing root barriers during construction.

When to hire professionals: Any driveway project involving trees over 10 cm diameter requires coordination between your paving contractor, a certified arborist, and potentially the City of Ottawa forestry department. Tree protection during construction is not DIY work — improper root cutting can destabilize large trees, creating safety hazards and liability issues. Professional arborists can also help design driveway layouts that work around existing trees rather than requiring removal.

Need help finding contractors experienced with Ottawa's tree protection requirements? Ottawa Driveways can match you with paving professionals who regularly navigate these bylaw requirements and work with certified arborists.