City of Milwaukie, OR Article III Private Trees in Residential Zones

§ 16.32.042 TREE PRESERVATION AND PLANTING WITH DEVELOPMENT IN RESIDENTIAL ZONES.

A. Applicability

The tree preservation and planting standards in this subsection apply in residential zones to the construction of a new residential dwelling unit(s) that results in an increase of building footprint.

B. Tree Preservation Standards

1. Healthy trees at least six-inch DBH are required to be preserved except when their removal is required for construction, demolition, grading, utilities, and other development impacts.

2. When a development application includes the removal of a healthy tree 30 inches DBH or greater, a Significant Tree Removal Fee shall be assessed in accordance with the consolidated fee schedule. This fee does not relieve the applicant of any other requirements of this chapter, including replacement trees, tree protection measures, or required arborist reports.

3. Preservation of at least 40% on-site healthy private tree canopy coverage is required unless mitigation is provided according to Subsection 16.32.042.E. See Figures 16.32.042.B.2-a and B.2-b for examples of when mitigation is or is not required. (See Subsection 16.32.042.D.3 for information on calculating tree canopy coverage.)

4. For development sites with 40% or less on-site healthy private tree canopy coverage, the removal of healthy private tree canopy is not allowed unless mitigation is provided according to Subsection 16.32.042.E.

5. Trees of any size that are listed on the Milwaukie Rare or Threatened Tree List must be prioritized for preservation; if removed, healthy trees from this list will incur an additional fee as listed on the Consolidated Fee Schedule.

6. Unhealthy trees and tree species on the Oregon State Noxious Weed List or Milwaukie Invasive Tree List, as well as trees within designated natural resource areas (as per Section 19.402) that are listed as nuisance species on the Milwaukie Plant List, are not required to be preserved in conjunction with applicable development as established in Subsection 16.32.042.A.

7. The applicant must provide a performance bond for existing trees that are preserved for purposes of addressing the 40% canopy coverage standard, to ensure their survival for such period of time as identified in the Consolidated Fee Schedule. On-site trees may be exempt from the performance bond requirements if the Urban Forester or an ISA Certified Arborist determine that construction activities do not present a significant impact to tree health. Existing trees used for canopy credit do not qualify for removal based on the criteria outlined in Subsection 16.32.044 D.2.(11).

Figure 16.32.042.B.2-a

Tree removal with mitigation

Figure 16.32.042.B.2-b

Tree removal without mitigation

C. Planting Standards

1. At least 40% tree canopy is required for a development site from existing healthy trees or new tree plantings unless mitigation is provided according to Subsection 16.32.042E. See Figure 16.32.042.C.1 for an example of tree planting where mitigation is not required.

2. The minimum size of newly planted trees is 1.5-inch caliper for broadleaf trees and five feet tall for conifers unless otherwise approved by the Urban Forester. Newly planted trees must be in good health with the size and quality consistent with ISA Best Management Practices and ANSI Z60.2 standards.

3. The species selection and spacing of trees to be planted must be such that it provides for the eventual mature size of the trees. Soil type, soil conditions and other site constraints must be considered when selecting species for planting.

4. Root barriers must be installed according to the manufacturer's specifications when a tree is planted within five feet of pavement or an underground utility box unless otherwise approved by the Urban Forester.

5. Where there are overhead high voltage utility lines, the tree species selected must be of a type that, at full maturity, will not require pruning to avoid interference with the lines.

6. Newly planted trees must survive a minimum number of years beyond the date of planting, with a performance bond to ensure that each new tree is replaced if it does not survive through the minimum period. See the Consolidated Fee Schedule for details. All trees planted for canopy credit would not qualify for removal based on the criteria outlined in Subsection 16.32.044D.2.(11).

Figure 16.32.042.C.1

Tree planting without mitigation

D. Tree Canopy Calculations and Credits

The following situations are eligible for credit towards tree canopy requirements when trees are planted or preserved in accordance with applicable City standards:

1. On-Site Trees

a. 100% of the existing crown area or mature crown area of on-site healthy private trees that are preserved, whichever is greater.

(1) In cases where a portion of the crown area of an on-site healthy private tree extends off site, the entire crown area is eligible for credit towards the tree canopy requirements.

(2) In cases where a portion of the crown area of an off-site private tree extends on site, the crown area is not eligible for credit towards the tree canopy requirements.

(3) Healthy on-site trees with DBHs of 12 inches or greater may receive additional canopy credits for existing or future mature crown area (whichever is greater) to be factored into preservation calculations as defined in the Consolidated Fee Schedule.

b. 75% of the future mature crown area of planted on-site private trees.

2. Street Trees

a. 50% of the existing crown area of street trees that are preserved in the public right-of-way directly abutting the development site.

b. 50% of the mature crown area of newly planted street trees in the public right-of-way directly abutting the development site.

3. Interpretations

a. When the trunk of a tree crosses a property line at ground level it is considered an on-site tree; except that when the trunk crosses a public right-of-way line at ground level, it is considered a street tree for the purposes of these tree planting standards.

b. Public right-of-way will be considered off-site for the purposes of these planting standard calculations.

c. Tree species on the Oregon State Noxious Weed List or Milwaukie Invasive Tree List are not to be included in the total canopy calculations.

d. Trees of any species that are less than six-inches DBH are not to be included in the total canopy calculations unless a bond is provided.

e. The Milwaukie Mature Tree Crown Area Reference List is the primary resource for determining the estimated tree canopy area for various species.

Table 16.32.042D summarizes the credits eligible for the tree canopy requirements of Section 16.32.042.

Table 16.32.042.D Eligible Credits for Tree Canopy Requirements
Tree Location	Existing Preserved Trees	Newly Planted Trees
On-Site Trees (Trees located within the tax lot)	100% of existing or future mature crown area, whichever is greater1	75% of future mature crown area
Street Trees (Street tees within the adjacent ROW)	50% of existing or future mature crown area, whichever is greater	50% of future mature crown area

1	Healthy on-site trees with DBH of 12 inches or greater may receive additional canopy credits for existing or future mature crown area—see Consolidated Fee Schedule.

E. Mitigation Fees

If the tree preservation and/or tree planting standards are not met, mitigation fees must be provided to the Tree Fund as follows:

1. The fee in lieu of preservation standard in the Consolidated Fee Schedule, based on the percentage of removed onsite healthy private canopy coverage below the 40% minimum tree canopy preservation standard established in Subsection 16.32.042B.

2. The fee in lieu of planting standard in the Consolidated Fee Schedule, based on the square footage of tree canopy that would be required to meet the 40% tree planting standard established in Subsection 16.32.042C.

F. Variance Procedure

An applicant may apply for a variance to the tree preservation and/or tree planting standards. An application for a variance will be heard and decided by the Planning Commission in accordance with the provisions of Section 19.1006 (Type III review) according to Section 19.911. In addition to meeting the Type III variance approval criteria established in Subsection 19.911.4.B, the applicant is required to demonstrate that equivalent or greater environmental benefits are provided as preserving or planting the required tree canopy.

Examples of activities that may justify a variance include but are not limited to:

1. Use of techniques that minimize hydrological impacts beyond regulatory requirements (examples include porous pavement, green roofs, infiltration planters/rain gardens, flow through planters, LIDA (low impact development approach) swales, vegetated filter strips, vegetated swales, extended dry basins, and constructed water quality wetlands).

2. Use of techniques that minimize reliance on fossil fuels and production of greenhouse gases beyond regulatory requirements through the use of energy efficient building technologies, on-site energy production technologies, and green buildings standards (Section 19.510).

3. Use of techniques that preserve and enhance wildlife habitat beyond regulatory requirements, including, but not limited to, the use of native plant species in landscape design, restoration of native habitat and preservation of habitat through the use of conservation easements or other protective instruments.

4. Use of techniques that preserve open space for sustainable urban agriculture through the use of conservation easements or other protective instruments at sites that are not compatible with tree canopy preservation or planting.

G. Tree Protection Standards

Trees to be retained must be protected from development impacts according to the standards in this subsection to be eligible for tree preservation and tree canopy credit. A tree protection plan prepared by an ISA Certified Arborist that demonstrates adequate protection of the trees to be preserved is required. The tree protection plan must be approved by the Urban Forester. Tree protection methods and specifications must be consistent with ISA Best Management Practices using either the prescriptive path or performance path tree protection methods as described below.

1. Prescriptive Path for Tree Protection

a. Root protection zone

(1) For on-site trees and off-site trees with root protection zones that extend into the site, provide a minimum one-foot radius (measured horizontally away from the center of the tree trunk) for each inch of trunk diameter at breast height. Root protection zones for off-site trees may be estimated.

(2) For street trees, the Urban Forester will prescribe the required root protection zone after reviewing the applicant's proposed root protection zone.

b. Encroachments into a root protection zone

(1) Existing encroachments into the root protection zone, including structures, paved surfaces and utilities, may remain.

(2) New encroachments into the root protection zone are allowed provided:

(a) The area of all new encroachments is less than 25% of the remaining root protection zone area when existing encroachments are subtracted; and

(b) No new encroachment is closer than half the required radius distance from the trunk (see Figure 16.32.042.G.1.b).

(3) Installation of landscape planting is not an encroachment.

(4) Any in-ground irrigation systems are considered encroachments.

Figure 16.32.042.G.1.b - Example of Permissible RPZ Encroachments

c. Protection fencing

(1) Protection fencing consisting of a minimum four-foot-high metal chain link or no-climb horse fence and secured with six-foot metal posts must be established at the perimeter of the root protection zone and permissible encroachment area on the development site. Existing structures and/or existing secured fencing at least 3.5 feet tall can serve as the required protective fencing. Protection fencing (new or existing) must be sturdy, highly visible, and not easily movable.

(2) When a root protection zone extends beyond the development site, protection fencing for private trees is not required to extend beyond the development site. Existing structures and/or existing secured fencing at least 3.5 feet tall can serve as the required protective fencing. If prescribed by the Urban Forester, protection fencing for street trees may extend beyond the development site.

(3) Protection fencing is required to be installed before any ground disturbing activities or construction begins, including clearing and grading, and must remain in place until final inspection.

(4) Signage designating the protection zone and penalties for violations must be displayed in a prominent location on each protection fence.

d. Prohibitions within the root protection zone

Except as allowed by Subsection 16.32.042.G.1.b, the following are prohibited within the root protection zone of each tree: ground disturbance or construction activity including vehicle or equipment access (but excluding access on existing streets or driveways), storage of equipment or materials including soil, temporary or permanent stockpiling, proposed buildings, impervious surfaces, underground utilities, excavation or fill, trenching or other work activities.

Variances from the prescriptive path protection standards for off-site trees are prohibited. The Urban Forester's determination of whether the prescriptive path standards are met is final and not subject to appeal.

2. Performance Path for Tree Protection

When the standards of the prescriptive path for tree protection cannot be met, the applicant may propose alternative measures to modify the prescriptive root protection zone and use a performance path for tree protection, provided the following criteria are met as approved by the Urban Forester:

a. An alternative root protection zone plan is prepared by an ISA Certified Arborist who has examined the specific tree's size, location, and extent of root cover, evaluated the tree's tolerance to construction impacts based on its species and health, and identified any past impacts that have occurred within the root zone.

b. The alternative root protection zone plan includes the rationale used to demonstrate that the alternate method provides an adequate level of protection based on the findings from a site visit by the project arborist.

c. If the alternative tree protection method involves alternative construction techniques, the project arborist has provided an explanation of the techniques and materials used.

d. The protection zone is marked with signage, stating that penalties will apply for violations, and providing contact information for the arborist.

H. Soil Volume Standards

1. General Standards

a. To be eligible for tree canopy credit as outlined in Subsection 16.32.042.D, planted trees must be provided access to at least 1,000 cubic feet of soil volume according to the standards in this subsection. A soil volume plan prepared by an ISA Certified Arborist is required and must demonstrate that at least 1,000 cubic feet of soil volume is available per tree as determined by the Urban Forester or designee. Soil volume methods and specifications must be consistent with ISA Best Management Practices using either the prescriptive path or performance path soil volume methods. The project arborist must verify with the Urban Forester in writing that the soil volume plan has been successfully implemented prior to tree planting.

b. If the existing soils at the site and abutting sites are determined by the project arborist or Urban Forester to be adequate to support healthy tree growth to maturity based on factors including but not limited to compaction levels, drainage, fertility, pH, and potential contaminants, the existing soils may be used to meet the soil volume requirements.

c. The assumed soil volume depth for planting will be three feet unless otherwise determined by the project arborist or Urban Forester.

d. A soil volume area of at least 333 square feet must be accessible to each tree when the assumed soil volume depth is three feet.

e. The soil volume areas must be continuous and within a fifty-foot radius of the tree to be planted. Continuous soil volume areas must be at least three feet wide for the entire area.

f. Trees may share the same soil volume area provided that all spacing requirements of this subsection are met.

g. Soil contaminants (i.e., soil containing construction debris, concrete, garbage, or any other substance that renders the soil inadequate to support healthy tree growth to maturity as determined by the Urban Forester) are prohibited from the soil volume areas.

2. Prescriptive Path for Soil Volume

a. Soil volume areas must be protected from construction impacts through any combination of the following methods:

(1) Protection fencing:

(a) Fencing consisting of a minimum four-foot-high metal chain link or no-climb horse fence, secured with six-foot metal posts established at the edge of the soil volume area on the development site. Existing secured fencing at least 3.5 feet tall can serve as the required protective fencing.

(b) When a soil volume area extends beyond the development site, protection fencing is not required to extend beyond the development site. Existing or new secured fencing at least 3.5 feet tall can serve as the required protective fencing.

(c) Signage designating the protection zone and penalties for violations must be secured in a prominent location on each protection fence.

(2) Compaction prevention options for encroachment into soil volume areas:

(a) Steel plates placed over the soil volume area, or

(b) A twelve-inch layer of coarse wood chips over geotextile fabric continuously maintained over the soil volume area, or

(c) A six-inch layer of crushed gravel over geotextile fabric continuously maintained over the soil volume area.

The Urban Forester's determination of whether the prescriptive path standards are met is final and not subject to appeal.

3. Performance Path for Soil Volume

a. When the standards of the prescriptive path for soil volume cannot be met; or if the existing soils at the site and abutting sites are determined by the Urban Forester to be inadequate to support healthy tree growth to maturity based on factors such as compaction levels, drainage, fertility, pH, and potential contamination prior to or resulting from development, a performance path soil volume plan is required.

b. Soils in areas of construction access that do not receive compaction prevention treatment and soils in areas of grading, paving, and construction are considered inadequate for tree growth unless a performance path soil volume plan is provided.

c. The following methods may be addressed in performance path soil volume plans but are dependent on specific site conditions and should be submitted by the applicant on a project basis in coordination with other professionals such as civil and geotechnical engineers, landscape architects, and soil scientists as needed:

(1) Compaction Reduction.

(a) Tilling.

(b) Backhoe turning.

(c) Subsoiling.

(2) Soil Amendments.

(a) Organic amendments.

(b) Mineral amendments.

(c) Biological amendments.

(d) Chemical amendments.

(3) Topsoil Replacement (when soil contamination or soil removal occurs).

(4) Soil Under Pavement.

(a) Structural soil cells.

(b) Structural tree soils.

(c) Soil vaults.

(d) Soils under suspended pavement.

I. Application Requirements

For all applicable developments, applications must be submitted by an ISA Certified Arborist that also has the ISA Tree Risk Assessment Qualification (TRAQ). Applications must demonstrate compliance with the applicable provisions of Subsections 16.32.042.B through H. Other professionals such as engineers, landscape architects, soil scientists, and surveyors may assist the project arborist as needed in preparing the required information, but the arborist must organize, review, and approve the final product. The minimum submittal requirements include an inventory of existing trees, tree preservation plan (if applicable), tree planting plan (if applicable), arborist report, and payment of review fee as established in the Consolidated Fee Schedule.

The following establishes requirements for the various submittal components:

1. Tree Inventory

a. Trees with any of the following characteristics must be inventoried:

(1) Six-inch DBH or greater;

(2) Two-inch DBH or greater listed on the Oregon State Noxious Weed List or Milwaukie Invasive Tree List;

(3) Less than six-inch DBH for species listed on the Milwaukie Rare or Threatened Tree List; and/or

(4) Less than six-inch DBH that will be preserved and included in the calculation of required canopy.

b. The location of all trees meeting the requirements of Subsection 16.32.042.I.1.a. must be identified, including:

(1) On-site trees;

(2) Trees within abutting public rights-of-way; and

(3) Trees on abutting sites and in the abutting right-of-way with root protection zones that extend into the site.

The locations and information for trees on abutting sites may be estimated.

c. Number each inventoried tree for identification at the site and on the plans.

d. Identify the common name and scientific name of each inventoried tree.

e. Measure the DBH of each inventoried tree in inches according to accepted ISA standards.

f. Measure the approximate average crown radius of each inventoried tree in feet.

g. Provide the crown area of each inventoried tree using the following formula: (crown radius)² x ℼ.

h. Assess the health condition of each inventoried tree using the following categories:

(1) Good (no significant health issues);

(2) Fair (moderate health issues but likely viable for the foreseeable future);

(3) Poor (significant health issues and likely in decline);

(4) Very Poor or Dead (in severe decline or dead).

i. Identify whether the inventoried tree is on the Milwaukie Rare or Threatened Tree List.

j. Identify whether the inventoried tree is proposed for removal or retention.

k. Organize the tree inventory information in a table or other format approved in writing by the Urban Forester.

2. Tree Preservation Plan

a. Provide a site plan drawn to scale.

b. Include the existing tree locations and corresponding tree numbers from the tree inventory and identify which trees are subject to potential impacts identified in Subsection 16.32.042.I.2.d.

c. Identify rare or threatened trees as described in the Milwaukie Rare or Threatened Tree List.

d. Identify the following site disturbances to scale:

(1) Demolition;

(2) Tree removal;

(3) Staging, storage, and construction access;

(4) Grading and filling;

(5) Paving;

(6) Construction of structures, foundations, and walls;

(7) Utility construction;

(8) Trenching and boring;

(9) Excavation;

(10) Any other demolition or construction activities that could result in ground disturbances and/or tree damage.

e. Locate tree and soil protection fencing to scale.

f. Locate soil compaction prevention methods to scale.

g. Identify prescriptive/performance path tree protection and soil volume areas.

h. Include tree and soil volume protection specifications from the arborist report on the plans including a detailed description of tree and soil volume protection fencing and signage.

i. The elements of the tree preservation plan may be included on multiple plan sheets for clarity.

j. The final approved set of construction drawings must include the tree preservation plan to ensure contractors, inspectors, and other professionals have access to the information.

3. Tree Planting Plan

a. Provide a site plan drawn to scale.

b. Include the existing trees to be retained and their crown areas to scale.

c. Include the trees to be planted and their mature crown areas to scale based on the Milwaukie Mature Tree Crown Area List.

d. Identify the soil volume areas for each tree to be planted to scale.

e. For prescriptive/performance path soil volume areas, identify the methods and specifications as applicable for:

(1) Protection fencing (including signage details);

(2) Compaction Reduction;

(3) Soil Amendments;

(4) Topsoil Replacement; and/or

(5) Soil Under Pavement.

f. The tree planting should demonstrate consistency with ISA Best Management Practices.

g. The elements of the tree planting plan may be included on multiple plan sheets for clarity.

h. The final approved set of construction drawings must include the tree canopy plan to ensure contractors, inspectors, and other professionals have access to the information.

4. Arborist Report

a. Provide a written narrative that summarizes the information from the tree inventory, tree preservation plan, and tree planting plan.

b. Provide findings and calculations that demonstrate whether the tree preservation standards in Subsection 16.32.042.B have been met.

c. Provide findings and calculations that demonstrate whether the tree planting standards in Subsection 16.32.042.C have been met.

d. If the tree preservation and/or tree planting standards have not been met, provide calculations for the applicable tree mitigation fees as required by Subsection 16.32.042.E.

e. If the applicant is seeking a variance to the tree preservation and/or tree planting standards in place of providing mitigation fees, provide findings that demonstrate the proposal provides equivalent or greater environmental benefits as preserving or planting the required tree canopy consistent as required by Subsection 16.32.042.F.

f. Provide findings that demonstrate compliance with the tree protection standards in Subsection 16.32.042.G.

g. Provide findings that demonstrate compliance with the soil volume standards in Subsection 16.32.042.H.

(Ord. 2247, 1/21/2025; Ord. 2254, 7/8/2025; Ord. 2261, 2/3/2026; Ord. 2263, 4/21/2026)

§ 16.32.044 NON-DEVELOPMENT PRIVATE TREE REMOVAL IN RESIDENTIAL ZONES.

The City encourages retention of healthy private trees where practical alternatives to removal exist, and where those alternatives meet the owner's objectives for reasonable use and enjoyment of the property. Where there is discretion in a decision about non-development private tree removal, various factors are considered to ensure that significant adverse impacts are avoided or mitigated, weighing the broader economic, ecological, and community concerns.

A. Applicability

A permit is required prior to the removal of the following private trees in residential zones:

1. Trees that are at least six-inch DBH.

2. Trees that are less than six-inch DBH as specified on the Milwaukie Rare or Threatened Tree List.

3. Trees that were planted to meet any requirements in Section 16.32.042 or 16.32.044.

B. Permit Exemptions

Tree removal permits are not required in residential zones when:

1. Tree removal is approved with development as provided in Subsection 16.32.042.A.

2. The removal of trees that are grown for commercial agricultural or horticultural purposes including fruit trees, nut trees, or holiday trees.

3. The removal is of a tree(s) within a designated natural resource area as regulated by Section 19.402. Such removal will be governed by the applicable standards of Section 19.402 unless otherwise noted. If the removal does not meet the approval criteria for a Type A permit as outlined in Subsection 16.32.044.D.2, a Type B permit will be required (including applicable mitigation fees as listed in the Consolidated Fee Schedule).

C. Applications

An application for a tree removal permit must be made upon forms prescribed by the City and contain the following:

1. Photograph(s) that clearly identify the tree(s) proposed for removal.

2. The number, DBH, species, and location of the trees proposed to be cut on a site plan of the property drawn to scale.

3. Information as to whether the tree is within a Habitat Conservation Area overlay district or is part of an approved landscape or mitigation plan.

4. Any additional information required by the City.

5. An application for a tree cutting permit must be accompanied by the correct fee as established in the Consolidated Fee Schedule.

D. Type A Tree Removal Permits

Type A tree removal permits are technical determinations regarding the facts of a particular request and the application of City standards to ensure that work is performed in accordance with ISA Best Management Practices to protect trees, the public, and public infrastructure, and to ensure appropriate tree replacement. Type A permits are reviewed administratively by the Urban Forester without public notice, and the decision may be appealed to the City Manager by the applicant.

1. Application Requirements

a. Applications for a Type A tree removal permit must meet the submittal requirements of Subsection 16.32.044.C.

b. Additional information may also be required.

(1) If the Urban Forester requires additional information to review an application, the Urban Forester will send a notice to the applicant requesting the additional information.

(2) The applicant will have a maximum of 30 days from the date of the Urban Forester's notice to submit the additional information.

(3) If the additional information is not received by the Urban Forester within 30 days from the date of the Urban Forester's notice, the application will be voided on the 31st day, with no refund of the filing fee.

2. Approval Criteria

A Type A permit will be issued only if the following criteria are met, as determined by the Urban Forester:

a. The proposed tree removal will be performed according to current ISA Best Management Practices.

b. The tree proposed for removal meets one or more of the following criteria:

(1) The tree is dead or dying and cannot be saved as determined by an ISA Certified Arborist in accordance with ISA standards.

(2) The tree has sustained physical damage that will cause it to die or enter an advanced state of decline. The City may require additional documentation from an ISA Certified Arborist to demonstrate that this criterion is met.

(3) The tree is having an adverse effect on existing infrastructure or buildings that cannot be mitigated by pruning, reasonable alternative construction techniques, or accepted arboricultural practices or the tree is located within 10 feet of a dwelling unit and presents a significant ongoing or unavoidable conflict with the structure as determined by the Urban Forester.

(4) The tree poses an unreasonable risk to the occupants of the property, the adjacent property, or the general public, as determined by an ISA Certified Arborist that is Tree Risk Assessment Qualified (TRAQ) in accordance with current ISA Tree Risk Assessment Best Management Practices.

(5) The tree is on the Oregon State Noxious Weed List or the Milwaukie Invasive Tree List, or, if located within a designated natural resources area as regulated by Section 19.402, the tree is listed as a nuisance species on the Milwaukie Plant List.

(6) The tree is part of a stormwater management system and has grown too large to remain an effective part of the system.

(7) The tree location conflicts with areas of public street widening, construction, or extension as shown in the Transportation System Plan and there is no practicable alternative to removing the tree.

(8) Tree removal is required for the purposes of a building or land use permit, utility or infrastructure installation, or utility or infrastructure repair and there is no practicable alternative to removing the tree.

(9) The tree is recommended for removal by a designated fire marshal for Clackamas County because it presents a significant fire risk to habitable structures or limits emergency access for rescue workers, and the risk or access issue cannot be abated through pruning or other means that would result in tree retention.

(10) An ISA Certified Arborist determines that thinning of interior trees within a stand of trees is necessary for overall stand health, the thinning will result in no less than 80% canopy cover at maturity for the area to be thinned, and that thinning of non-native trees is maximized prior to thinning of native trees.

(11) Healthy trees. One healthy tree may be removed per tax lot per twelve-month period if the tree is less than 12 inches in diameter at breast height and is not required to be preserved by a condition of a land use review, a provision of Chapter 16.32 or Title 19, or as part of a required stormwater facility.

3. Mitigation Requirements

Unless removed for thinning purposes (Subsection 16.32.044.D.2.b(10)) or invasive species status (Subsection 16.32.044.D.2.b.(5)), replacement of a removed tree is required as mitigation. The Urban Forester will condition the removal of each tree upon the planting of a replacement tree as follows:

a. The minimum size of replacement trees is 1.5-inch caliper for broadleaf trees and five-foot tall for conifers unless otherwise approved by the Urban Forester. Trees planted must be in good health with the size and quality consistent with ISA Best Management Practices and ANSI Z60.1 standards.

b. Replacement trees must be planted in a manner consistent with ISA Best Management Practices.

c. The replacement tree must substantively replace the function and values of the tree that was removed wherever practicable. For example, a long-lived evergreen native tree that abuts a designated natural resources area (as per Section 19.402) must be replaced with a long-lived evergreen native tree that abuts a designated natural resources area.

d. If planting a replacement tree is not practicable, the Urban Forester may allow a tree replacement fee in lieu according to the Consolidated Fee Schedule.

4. Decision by the Urban Forester

a. The Urban Forester's decision will be based on an evaluation of the facts and applicable standards and review criteria in Subsection 16.32.044D.2.

b. The Urban Forester may issue the permit, deny the permit, or may apply conditions of approval to the permit to ensure the request complies with the applicable review criteria and standards.

c. Any work done under a permit must be performed in strict accordance with the terms and provisions of this chapter and conditions of approval of the permit.

d. The Urban Forester must notify the applicant of the decision in writing.

e. If no appeal is filed as specified in Subsection 16.32.044E.5, the decision of the Urban Forester is final.

E. Type B Tree Removal Permit

A Type B tree removal permit may be approved by the Urban Forester if the Type A tree removal approval standards cannot be met. Type B permits involve the consideration of relevant technical and qualitative factors to prevent risks to public health and safety and to ensure that the impacts of tree removal are mitigated. Type B permits are reviewed administratively by the Urban Forester. The Type B process is more discretionary than the Type A process and may consider a range of options for approving, approving with conditions, or denying a tree removal permit application.

1. Application Requirements

a. Applications for a Type B tree removal permit must meet the submittal requirements of Subsection 16,32.044.C.

b. Additional information may also be required.

(1) If the Urban Forester requires additional information to review an application, the Urban Forester will send a notice to the applicant requesting the additional information.

(2) The applicant will have a maximum of 30 days from the date of the Urban Forester's notice to submit the additional information.

(3) If the additional information is not received by the Urban Forester within 30 days from the date of the Urban Forester's notice, the application will be voided on the 31st day, with no refund of the filing fee.

2. Review and Approval Criteria

The City will not issue a Type B permit for the removal of a healthy, functioning tree without a demonstration by the applicant that extraordinary circumstances exist. Maintenance or the replacement of pavement, removal of tree litter, or other minor inconveniences may or may not constitute extraordinary circumstances.

Decisions regarding removal of healthy, functioning trees are fact-specific and are made on a case-by-case basis by the Urban Forester. In determining whether extraordinary circumstances exist that warrant the major pruning or removal of a healthy tree, the Urban Forester will consider:

a. Whether the species of tree is appropriate for its location;

b. Whether the crown, stem, or root growth has developed in a manner that would prevent continued healthy growth or is negatively impacting other trees;

c. Whether maintenance of the tree creates an unreasonable burden for the property owner; and

d. Whether the removal will significantly affect public safety or neighborhood character based on the following:

(1) The age, size, form, species, general condition, pruning history and any unique qualities or attributes of the trees;

(2) The cumulative impacts of current and prior tree removals in the area; and

(3) When the tree is associated with a grove, whether removal of the tree will have a significant adverse impact on the viability of other trees or make other trees considerably more vulnerable to windthrow.

3. Mitigation Requirements

a. Replacement of a removed tree is usually required as mitigation. The Urban Forester will at a minimum condition the removal of a tree based on Subsection 16.32.044.D.3 (planting standards and exceptions for thinned or invasive-species trees). In addition, the Urban Forester will condition the removal of each tree upon the planting of additional replacement tree(s) as outlined in Table 16.32.044.E.3:

Table 16.32.044.E.3 Required Replacement Trees for Type B Permits
Diameter at Breast Height (DBH) of Tree Removed	Number of Additional Trees Required Beyond 1:1 Replacement	Total Replacement Trees Required
6" DBH to <12" DBH		1 tree
12" DBH to <24" DBH	1 trees	2 trees
24" DBH to <36" DBH	2 trees	3 trees
36" DBH or greater	3 trees	4 trees

b. In addition, mitigation fees must be provided to the Tree Fund for each healthy private tree removed in conjunction with an approved Type B permit. See the Consolidated Fee Schedule for details.

4. Decision by the Urban Forester

a. The Urban Forester's decision must be based on an evaluation of the facts and applicable standards and review factors in Subsection 16.32.044.E.2.

b. The Urban Forester may issue the permit, deny the permit, or may apply conditions of approval to the permit to ensure the request complies with the applicable review factors and standards.

c. Any work done under a permit must be performed in strict accordance with the terms and provisions of this chapter and conditions of approval of the permit.

d. The Urban Forester must notify the applicant of the decision in writing.

e. If no appeal is filed as specified in Subsection 16.32.044.E.5, the decision of the Urban Forester is final.

5. Appeals

The applicant may appeal the Urban Forester's decision.

a. Appeals must be:

(1) Filed with the Urban Forester on forms prescribed by the City;

(2) Filed within 14 days from the date of the Urban Forester's decision; and

(3) Specifically identify how the Urban Forester erred in applying the standards or review criteria.

b. Appeals are heard by the City Manager.

(1) The City Manager will consider the application against the applicable standards or review criteria, taking into consideration information provided by the applicant and City staff.

(2) The City Manager may affirm or reverse the Urban Forester's decision or remand the decision to the Urban Forester to determine appropriate actions.

(3) The appeal decision of the City Manager is final and may not be appealed to another review body within the City.

(Ord. 2247, 1/21/2025; Ord. 2254, 7/8/2025; Ord. 2261, 2/3/2026; Ord. 2263, 4/21/2026)