Since October 1, two tree permits at Lake Oswego City Hall cost the same $26. One covers an ordinary Type I removal, such as a 12-inch maple crowding the patio, and it requires you to plant a new tree. The other covers an ash tree in the same backyard. In most cases it requires no replanting, even when the tree looks healthy.
The city is asking homeowners to replace the trees they choose to remove. It is also clearing the way for them to take down a species that state foresters expect to lose almost entirely.
Same Fee, Different Obligations
The updated tree regulations took effect October 1, 2026. The City's notice lists the changes: Type I permits now require mitigation, except for fruit trees. There is a new over-the-counter permit for ash, and ash trees are off the Native Tree Mitigation List. The City's 2024 Type I application asked for a site plan but no mitigation plan. Type I is the permit most homeowners use, so that is the part of the change they will notice first.
The City's tree permit table shows how the permit types compare for a private yard:
| Permit type | What it covers | Replacement tree required? | 2026 fee |
|---|---|---|---|
| Type I | Up to two trees per calendar year at 6 to 15 inches DBH, or any number of fruit trees, in private residential yards | Yes, 1:1, except fruit trees | $26 |
| Dead, declining or EAB-susceptible | Trees dead or in irreversible decline, or species susceptible to emerald ash borer | Only in the public right-of-way, Sensitive Lands, or an approved mitigation or landscape plan | $26 |
| Hazard | Trees likely to fall and injure people or property, or damaging utilities | In some circumstances | $26 |
| Type II Discretionary | Trees that have outgrown their space, or removal for landscaping | Yes | $261 first tree, $26 each additional |
| Emergency | Trees in immediate danger of collapse | No | None |
Any tree 6 inches or more in diameter at breast height, measured 4.5 feet off the ground, needs a permit. The new general application form states the Type I rule plainly: "Mitigation Plan Required (at a 1:1 planting ratio; no mitigation required for fruit trees)." For dead, declining or EAB-susceptible trees, it asks for photos taken up close and of the canopy. A mitigation plan applies only in the three listed situations.
Why Ash Got Its Own Permit
Emerald ash borer is the reason. Here is the beetle's progress through the region:
- June 30, 2022. The Oregon Department of Agriculture records the state's first detection, in Forest Grove.
- September 2025. A joint release from state agencies and Portland Parks & Recreation reported new detections at Hazeldale Park and Killin Wetlands in Washington County, at two Clackamas County locations, and at David Douglas Aquatics Center in Multnomah County.
- August 2026. OPB reported that the beetle had spread to Multnomah, Clackamas, Yamhill and Marion counties, with notable infestations in Tualatin, Newberg and Northeast Portland. It was also newly confirmed in Beaverton, Salem, Silverton and the Rock Creek area.
Clackamas County is now inside the state's permanent EAB quarantine, along with Washington, Yamhill, Marion and Multnomah counties. The infestation OPB named in Tualatin is just across the city's southern border. In the same OPB report, forestry officials said Oregon could lose up to 99% of its ash trees over time.
That projection explains the rest of the ash changes. The City describes the new permit as a way to remove ash trees "in preparation for Emerald Ash Borer," so the permit is meant to be used before a tree declines. Ash also came off the City's Native Tree Mitigation List and Master Plant List. The updated lists point to drought-tolerant and wildfire-resistant species as substitutes. So when a Lake Oswego homeowner plants a replacement for any removed tree, an ash no longer counts.
Telling an Ash From Everything Else in the Yard
The ash permit only helps if you know which tree is an ash. The state's EAB identification guide lists these signs:
- Leaves. Deciduous and pinnately compound, usually with 5 to 9 leaflets.
- Branching. Twigs and branches grow in opposite pairs.
- The beetle. Metallic green, about 3/8 to 1/2 inch long, and hard to spot. Other green insects can look similar.
- Damage. Canopy thinning from the top down, sprouts, bark splits, S-shaped larval galleries under the bark, and clean D-shaped exit holes about 1/8 inch wide.
The same guide says suspected sightings can be reported to the Oregon Invasive Species Hotline. The state's EAB status map is the resource for where the beetle has been confirmed.
What the Replacement Tree Looks Like
For a Type I removal, a replacement tree is now part of the cost of the project. The City's mitigation handout gives examples of planting size: a deciduous tree with a 1.5-inch caliper or a 6-foot evergreen. It also says staff may specify the species or stature.
The replacement goes on the same property first. If the City decides there isn't room, the owner can plant on another property they own or control within the city. A payment to the City's Tree Fund is the last option. The City Council sets that fee each year.
This rule matters most on smaller lots where the canopy is already dense. There, removing one tree often means figuring out where its replacement can actually grow. Planning that before you file is part of the project.
The Bigger Debate Was About Development
Most of the debate over the code was about development, not backyards. In May, the Lake Oswego Review reported that the update had two drivers. A state law requires "clear and objective standards" for tree removal. Some residents also worried that developers could remove trees too easily while risky trees were too hard to remove. In the same story, Mayor Joe Buck pointed to the January 2024 ice storm. "Lake Oswego has the highest tree canopy in the region, so our goals are slightly different than most other communities who are looking to grow their canopy," he said.
The Review reported in July that the City Council approved two ordinances on July 21. Here is how the result affects homeowners:
- The 45% retention standard applies to new housing. The new Clear and Objective Track covers Type II removals for new dwelling units and new residential lots, which generally must keep at least 45% of their trees. Ordinary yard removals are not part of it.
- Type II reviews move faster. The public comment period dropped from 14 days to 7. Appeals of staff decisions now go to a hearings officer, whose decision is final. Before, they went to the Development Review Commission.
- Moderate-risk trees have a new route. The Type II Discretionary Track now offers a limited way to remove trees rated moderate risk when certain criteria are met.
- Right-of-way trees are still unsettled. Council postponed the question of who pays to remove dead trees in the public right-of-way. In May, staff estimated that maintenance on such a tree can approach $6,000. They added that EAB-related work will push those costs higher.
The ash permit makes removal easy in private yards, while the question of who pays for ash trees and other trees along the street is still open.
Two Thursdays at City Hall
As of late October, the City's online code does not yet include the amendments. The City expected its eCode360 vendor to add them by the end of the month. Until then, the adopted text is in Ordinance 2978, which covers the tree code, and Ordinance 2974, which covers the Community Development Code. The City stopped accepting older application forms on October 1. The current versions are on its printable forms page.
The City is holding two hybrid workshops, each 5 to 6:30 p.m. You can attend in person or online, and you must register in advance:
- Thursday, Oct. 29: Tree Removal Permits: Permit Types & Recent Code Amendments
- Thursday, Nov. 12: Clear & Objective Track Type II for Residential Development
For questions about a specific property, contact the Planning Department at [email protected] or 503-635-0290. This post is general information, not legal advice. The City's planning staff and a certified arborist are the right people to confirm how the rules apply to your trees.
A replanting obligation or an ash tree near the deck can become part of the conversation when a Lake Oswego home changes hands. If you're planning yard work before a sale, or weighing a home with a mature canopy, Matt Booth Winback can go over what the new code means for that property. Let's Connect.
