Tree Removal Permit in Lake Oswego, OR
Permit Summary
Do You Need a Tree Removal Permit?
Exemptions
A tree-removal permit is generally not required for a tree under 6 inches DBH. Normal pruning does not require a tree-removal permit, but topping or removal of 50% or more of a tree's crown is regulated as removal. The City also states that no removal permit is required when an entire tree has already fallen to the ground. Stumps, shrubs, and hedges that are not regulated as trees are outside the ordinary tree-removal permit requirement.
Protected Trees & Removal Eligibility
Protected Tree Rules
The current Discretionary Type II materials classify certain trees as significant, including Douglas-fir at 35 inches DBH or greater; grand fir, ponderosa pine, western hemlock, and western redcedar at 24 inches DBH or greater; Oregon white oak, madrone, and Pacific yew greater than 15 inches DBH; other non-invasive species at 30 inches DBH or greater; designated Heritage Trees regardless of size; and specified last-remaining trees on a property. Trees protected by a prior development approval, Heritage Trees, trees on Historic Landmark properties, and trees in specified overlays or special setbacks are not eligible for the ordinary Type I pathway and may require another review path.
When Removal Is Allowed
Lake Oswego uses several permit paths. Type I is an over-the-counter path for qualifying small trees and edible fruit trees on eligible private residential property. Separate paths exist for dead/dying and EAB-susceptible trees, hazard trees, emergency trees, invasive species, verification of trees already approved through development review, and forest management. Other removals use Type II review. Discretionary Type II requires findings addressing the reason for removal and impacts, and the 2026 amendments add a pathway for qualifying moderate-risk trees. Ash trees may use the Dead, Dying and EAB-Susceptible permit with positive identification by a certified arborist or photo verification; the City restricts ash pruning and removal to October 1 through March 31 during the EAB dormant season.
Replacement Requirements
Replacement Rules
Mitigation depends on the permit type and site. Current City materials require 1:1 replacement for Type I, Type II, and Verification removals, except qualifying significant trees removed for development under Type II or Verification generally require 2:1 mitigation. Edible fruit trees removed under Type I do not require mitigation. Dead/dying/EAB-susceptible, hazard, and invasive-tree removals require replacement in specified locations or circumstances, including public right-of-way when replanting is required, protected Sensitive Lands, or trees required by an approved landscape or mitigation plan. Standard replacement size is generally at least a 1.5-inch-caliper deciduous tree or a 6-foot-tall evergreen; native-tree removals require native replacement where specified. Planting is generally on site first; if the City determines planting is infeasible, approved off-site planting or payment into the City Tree Fund may be used. Mitigation planting is typically due within 90 days unless the permit establishes another schedule, and the City inspects planted mitigation trees.
Arborist & Professional Requirements
Professional Requirements
When professional documentation is required, Lake Oswego uses qualified arborists. The City defines an arborist by International Society of Arboriculture certification. Clear and Objective Type II applications require the tree inventory to be prepared by a certified arborist. Hazard applications may require a Tree Risk Assessment Qualification (TRAQ) arborist to complete the City's hazard evaluation when photographs do not establish the required risk level. The City may also require an arborist report for Discretionary Type II review. The rules do not establish a general requirement that every permitted tree removal be performed by an arborist.
Public Notice Requirements
Notice Rules
Public notice applies to Type II review, not ordinary over-the-counter permits. Under the rules effective October 1, 2026, the Type II public-comment period is 7 days. Discretionary Type II applications use the City's notice form, yellow tree markings, and a public notice sign maintained for the comment period, with neighborhood-association notice. For qualifying Clear and Objective Type II applications, state law limits mailed notice to properties within 100 feet and the City does not use the ordinary yellow site-notice sign; only the applicant may appeal a Clear and Objective decision. Appeals of Type II staff decisions are heard by a hearings officer under the updated process.
Emergency Tree Removal
An emergency tree is one presenting an immediate danger of collapse and a clear and present hazard to persons or property, or a tree whose removal is immediately necessary to restore interrupted utility service. When an emergency occurs outside normal City processing hours, removal may proceed only to the extent necessary to address the immediate hazard; photographs must document the condition, and the owner must apply for a retroactive emergency tree-removal permit within 7 days. The City may require an independent arborist review if the emergency status is not adequately established.
Development & Special Areas
Development-Related Rules
The 2026 amendments created a Clear and Objective Type II track for qualifying tree removal associated with new or replacement dwelling units, accessory dwelling units, and creation of residential lots. Qualifying Clear and Objective projects generally must meet a 45% minimum tree-retention standard; projects below that standard are subject to the adopted Tree Retention Deficit Fee. Clear and Objective submittals include a certified-arborist tree inventory and tree-protection plan, and the amendments also added street-tree planting requirements. Other Type II removals, including many additions or remodels unrelated to new housing and projects using discretionary review, remain on the Discretionary Type II track. Trees already approved for removal through a major or minor development decision may use the Verification Permit process. Tree-protection measures and a staff inspection are required before specified development work or building-permit issuance when tree protection applies.
Special Zone Rules
Type I removal is not available for trees protected by a development approval; designated Heritage Trees; trees on properties on the Historic Landmark Designation List; trees in Resource Conservation (RC), Resource Protection (RP), or Habitat Benefit Area (HBA) protection areas; trees in the Willamette River Greenway overlay; trees within the 25-foot Oswego Lake Special Setback; or trees on City-owned or public property, including public rights-of-way. These trees may require another permit path and additional findings or mitigation. Sensitive Lands and public right-of-way locations can trigger replacement requirements. Work in the public right-of-way also requires the City's applicable traffic-control authorization before tree work.
What You Need Before Applying
Requirements
Determine the applicable tree-removal permit category before work begins. For regulated trees, submit the applicable City application with owner authorization and required plans or evidence, identify and mark the tree as required, pay the applicable fee, and obtain approval before removal unless the emergency procedure applies. Additional tree-protection, right-of-way, development, mitigation, or professional documentation requirements apply in specified circumstances.
Required Documents
Submittals depend on the permit path. General applications require applicant and property-owner information/authorization, a site plan identifying the tree(s), and a mitigation plan when required; dead, hazard, and emergency requests require photographs, and a hazard request may require the City's hazard evaluation form. Discretionary Type II applications require the Type II application, notice materials, site plan, mitigation plan, and applicable checklist, landscape plan, or arborist report. Clear and Objective Type II applications require a notice form, tree-protection plan, and a tree inventory prepared by a certified arborist, with mitigation information.