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Tree Protection and Removal

The purpose of the Tree Code is to preserve the wooded character of the City of Lake Oswego and to protect trees as a natural resource of the City by:

  • Regulating the removal of trees;
  • Encouraging and assisting property owner in managing large forested properties; and
  • Prescribing preventative protection measures to avoid damage to trees during site development.

What trees are regulated by the Tree Code?

Any woody plant with a trunk that is 6 inches in diameter at breast height (DBH) or greater with the capacity to achieve a mature height greater than 16 feet. Stumps, shrubs and hedges, including rhododendrons, camellias, English laurel, Portuguese laurel, photinia, arborvitae, and hazelnut, are not considered trees.

How do I measure the diameter at breast height (DBH) of a tree?

DBH is determined by measuring the circumference (all the way around the trunk of the tree) in inches of the main trunk at 4.5 feet above the ground and dividing by pi (3.14). If the main trunk splits into smaller leaders below 4.5 feet, measure the circumference just below the trunk split.

Diameter at Breast Height