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Street Tree Planting Requirements

There are requirements for trees planted along public or private roads and access roads, including types of trees, setbacks and more.

Regulations for street trees

Urban Street Tree Standards
Urban Street Tree Standards

Requirements for street trees - those fronting public or private streets or access drives - within the Urban Growth Boundary.

CDC Section 407-7

Corner Vision
Corner Vision Street Trees

Lots or parcels on street corners must maintain sight requirements 

CDC Section 418-3

Approved Street Trees
Approved Street Trees

Our list of Approved Street Trees are in our Road Design and Construction Standards. Species are appropriate for street and sidewalk frontages.

Street Tree List

407-7 Urban Street Tree Standards

Inside an urban growth boundary, when fronting on public or private roadways or access drives, new structures including a Single Detached Dwelling Unit or Duplex on an existing lot or parcel, or Middle Housing, and any Standard Land Division or Middle Housing Land Division, shall be required to plant street trees in accordance with the following standards:


The species of street trees to be planted shall be chosen from the approved list of street trees unless approval of another species is given by the Director through a Type I procedure. Trees shall be selected and spaced to provide canopy overlap for shade. Trees shall be installed at an average of one tree per 35 feet of lineal road frontage unless otherwise required by district standards, or the Director approves, through a Type I procedure, a greater average spacing based on submitted evidence demonstrating the approved species typically requires such spacing, and that the alternative spacing will result in canopy overlap.


Exemption from the requirement to plant street trees may be granted by the Director to the extent that existing trees meet location and diameter requirements below. This exemption may be granted through a Type I procedure;


Street trees shall be installed on public or private property no more than five feet from the designated right-of-way; and


Street trees shall be a minimum of 1½ inches in diameter as measured at four feet above grade.

481.3 Corner Vision

Lots or parcels on street corners (public and/or private) shall maintain a sight triangle with no sight obstruction between 3 feet and 10 feet in height as measured from street grade. Sight obstructions include, but are not limited to, fences, vegetation, berms, and structures. The sight triangle shall be measured from the street corner (apex), a distance of 20 feet along each street side (see Figure 1). For the purpose of this Section, street corner is defined as that point where the extended edge of the road surface of two intersecting streets meet. The county may require additional vision clearance based on a hazard identified by the county. Nothing in this Section shall supersede proper application of the sight distance standards in Section 501-8.5 F.


You can plant a street tree in unincorporated Washington County without a permit, except in Significant Natural Resource areas. (See: How do I know if my property is in a Significant Natural Resource area.)

You need a right-of-way permit if tree planting or removal impacts traffic. Visit Planting or Removing Street Trees.

For the urban unincorporated area (areas outside of cities), the County's map showing areas with SNRs are found in the  community plans. Staff can assist you via email or in person by visiting our offices during regular business hours

For lands outside the Urban Growth Boundary (UGB), the Rural/Natural Resource Plan (RNRP) contains maps that show the properties that may have SNR areas.

Please contact Development Review/Current Planning to confirm the location and types of mapped SNR on your site by emailing [email protected] or calling 503-846-8761. Staff can also assist you in person. Visit us in Suite 350 in the Public Services Building during regular business hours. 

The County does not regulate tree removal on private properties unless the trees are located in County-designated Significant Natural Resource (SNR) areas. Email [email protected] to determine if the trees are in an SNR area before removing them.

In all other areas, tree removal is typically at the discretion of a property owner and does not require a permit unless removal impacts traffic. Visit Planting or Removing Street Trees.

Neighboring property owners who disagree with tree maintenance/removal may be eligible for free mediation services through Beaverton Center for Mediation and Dialogue (east of 185th Avenue) or Hillsboro Mediation Program (west of 185th Avenue). 


Contact Us

Development Review/Current Planning



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