Skip to Main Content


February 26, 2015

A City Council goal from 2014 is to “Amend the tree code to more appropriately address large land parcels, both private and public, for forest management.” (A related goal for 2015 is to initiate a community dialogue on other aspects of the Tree Code.) On October 7, 2014 the City Council received a staff presentation on the Tree Code with respect to large forested parcels. At that study session, Council directed staff to proceed in developing code amendments.

On March 10, 2015, the City Council will hold a study session on Ordinance 2664 (PP 14-0005). A public hearing is scheduled for March 17, 2015.  To learn more about the proposed amendment, click here.


One of the benefits of living in Lake Oswego is the abundance of trees in the city — we live in an urban forest. Much of the character of the City of Lake Oswego is defined by trees. Lake Oswego leads other communities in its overall protection of trees. Street trees beautify the City and soften the built landscape. Trees in parks and natural areas provide shade and wildlife habitat. Trees in neighborhoods impart a sense of place and connection to the natural world. The urban forest as a whole adds to the livability and desirability of the community. Trees are essential to the urban ecosystem, cleaning our air, helping rainfall infiltrate, cooling buildings and streets, and absorbing city noise.

Regulation of tree removal through the permit process protects the natural setting in Lake Oswego. The city has regulated tree removal and mandated tree protection by local law for approximately 30 years.  Anyone proposing to remove a tree over five inches in diameter is required to go through a permit process and justify the tree removal.  The city regularly requires the planting of replacement (or mitigation) trees when other trees have been permitted to be removed. Both homeowners and businesses are required to obtain a permit to cut a tree.

Type I Permit

The Type I Permit is for trees between 5 and 10 inches DBH. It is issued at the Planning counter and is easy to get. Type I Permits are only available for residentially zoned property developed with a single family dwelling, and only two trees may be removed per calendar year per residential lot.

Type II Permit

A Type II Permit is for trees that do not qualify for a Type I, Invasive, Dead, Hazard, Emergency or Verification Permit (see terms defined later in this brochure). This includes trees greater than 10” DBH on all lots within the City. The Type II permit requires more intensive evaluation and staff time, and takes approximately one month to complete. The applicant posts a sign, obtained from the City, that describes the proposed tree removal. This begins the 14-day public comment period, during which staff reviews the application and makes a site visit. At the end of the comment period, staff issues a tentative decision. If the tentative decision is for approval, a second sign will be posted by staff which starts a 14-day appeal period. During this period, the tentative decision can be appealed to the Development Review Commission.

Dead Tree Permit

Dead tree permits can usually be issued at the Planning counter with appropriate evidence. However, between November 1 and April 15, permits for dead deciduous trees require a site visit by City staff because all deciduous trees look dead in the winter. Unless the tree is deemed a hazard to persons or property, Dead Tree Permits may not be issued for trees located in stream corridors or protected tree groves.

Hazard Tree Permit

A Hazard Tree permit is issued for trees that are cracked, split, leaning or physically damaged to the degree that it is clear that the tree is likely to fall and injure persons or property and where pruning will not alleviate the hazard. This application requires a Hazard Evaluation Form completed by a certified arborist, which gives the tree a hazard rating based on failure potential, size of the part most likely to fall, and what activity or structure is under the tree. Hazard Tree Permits require staff review.

Invasive Tree Removal

The City encourages the removal of invasive tree species by offering an expedited removal permit at no cost. The City does not require the removal of invasive tree species, but offers an easy and efficient process for property owners wanting to do so. (See Invasive Species Tree Identification Guide below.)

Emergency Tree Permit

An Emergency Tree permit is issued for trees that present an immediate danger of collapse and represent a clear hazard to persons or property.  “Immediate danger of collapse” means that the tree is already leaning, surrounding soil is heaving, and there is significant likelihood that the tree or a portion of it will fall before a tree cutting permit can
be obtained through a non-emergency process.

Verification Permit

A Verification Tree Permit is issued for sites that have received development approval through a Major or Minor Development Process during which specific trees were identified for removal.

Tree Protection Permit

Tree protection fencing is required prior to conducting any development activities including, but not limited to, clearing, grading, construction, excavation, or demolition work on any site.