2021-10-05_TreeProtectionProceduresL:/FORMS/Tree Protection/2021-10_TP_APPLICATION-General/2021-10-05_TreeProtectionProcedures
PLANNING AND BUILDING SERVICES
TREE PROTECTION PROCEDURES & INFORMATION
(also, for Sensitive Lands District protection)
Email codeenforcement@lakeoswego.city or Phone 503-635-0290 to schedule
a site visit consultation or a tree protection inspection.
1. Inspection Required:
a. Prior to any development activities (unless a pre-construction activity listed below); and,
b. Prior to issuance of a building, demolition and plumbing permit or a Notice to proceed.
Fencing and other protection measures must be installed, inspected, and approved before beginning
development.
2. Site consultation available: An applicant may schedule a meeting at the property with an inspector to discuss
tree protection measures prior to installing tree protection fencing. The meeting should include a certified
arborist and the excavation contractor;
3. Pre-construction activities: Limited activities may occur prior to the issuance of a Tree Protection plan if a
certified arborist is present to avoid tree damage or injury. Examples: exploratory excavation by hand to locate
tree roots; and, the cutting of understory vegetation to install tree protection and erosion control measures;
4. Tree protection zone – determining the fence locations.
a. Find the drip-line of the tree canopy;
b. Determine the protection radius of the tree; measure the trunk diameter 4.5’ from the ground and
extend out 1’ of protection radius for each 1” of trunk diameter; and,
c. Mark the location (drip-line or protection radius) that is the greater distance from the trunk;
5. Arborist report: A report from a certified arborist is required if protection fencing cannot be installed at the
edge of a tree protection zone as described in #4 above. The report shall provide the information provided on
the “Arborist Report – Information & Inspections Required” document for each tree with a modified tree
protection zone.
6. Fencing minimum requirements:
a. Height: Provide a minimum 4-foot high metal fence i.e. chain-link, chain-link panels, or heavy gage wire.
b. Posts, spacing and panels: Place fence posts no more than 8 feet apart.
i. Fence panel bases must be anchored with rebar or metal posts buried 2’ or more.
c. Flush with grade: Install fencing flush with the initial undisturbed grade of the protection zone.
d. Signs: Attach a City approved sign to every 3rd fence panel/section (sign template attached).
e. Maintenance: Maintain protection fencing in good effective condition at the inspected location. Repair
damaged fencing prior to resuming work in the area.
f. Removal: Remove fencing only after: installation of utilities and stormwater improvements; construction
of driveway/parking areas; and completion of exterior building walls.
7. Sensitive lands district and required open space tracts/easements: Install protection fencing at resource
boundaries of streams and wetlands and at the edge of open space tracts/easements which are on, or adjacent
to the development area.
a. Surveyor Statement: Provide a statement from a licensed surveyor confirming the boundary of the
sensitive land resource (stream or wetland) was surveyed and staked for placement of the protection
fencing.