The purpose of this chapter is to establish processes and standards that ensure the City maximizes the environmental, economic, health, community, and aesthetic benefits provided by its urban forest. It is the intent of this code to establish, maintain, and increase the quantity and quality of tree cover in the City, and to ensure our urban forest is healthy, abundant, and climate resilient.
This code is designed to:
1. 
Foster urban forest growth to achieve 40% canopy coverage by 2040.
2. 
Maintain trees in a healthy condition through best management practices.
3. 
Manage the urban forest for a diversity of tree ages and species.
4. 
Manage street trees appropriately to maximize benefits and minimize hazards and conflicts with infrastructure.
5. 
Ensure the preservation and planting of tree canopy with development and redevelopment of housing in residential zones.
6. 
Regulate the removal, replanting, and management of trees prior to and following development and redevelopment in residential zones.
7. 
Implement applicable urban forest goals, policies, objectives, and action items in the Comprehensive Plan, Climate Action Plan, and Urban Forest Management Plan.
(Ord. 2247, 1/21/2025)
The following definitions will apply for terminology used in this chapter. If a definition is not listed in this chapter, the definition in Title 19 will apply. Where definitions are not provided in this chapter or Title 19, their normal dictionary meaning will apply:
"Arbor Day/Week"
means a day/week designated by the City to celebrate and acknowledge the importance of trees in the urban environment.
"Arboriculture"
means the practice and study of the care of trees and other woody plants in the landscape.
"Building footprint"
means the area covered by the outer structural walls of a building, measured in square feet. Included in the calculation of footprint are: roofed structures that are not fully enclosed; building features such as patio covers, roofed porches, and decks; or similar features with a surface height of more than 18 inches above average grade. Footprint does not include eaves.
"Caliper"
is the trunk diameter for nursery stock trees measured six inches from the soil line; if caliper is greater than four inches, the caliper measurement is taken at 12 inches from the soil line.
"Canopy"
is the layer of leaves, branches and stems of trees that cover the ground when viewed from above. Canopy cover is measured as the proportion of a fixed area of the ground covered by tree crowns.
"City"
means the City of Milwaukie.
"City Engineer"
means the city engineer of the City of Milwaukie or designee.
"City Manager"
means the city manager or the city manager's authorized representative or designee.
"Consolidated Fee Schedule"
is the schedule of City fees and charges adopted by City Council for the services provided by the City.
"Council of Tree and Landscape Appraisers (CTLA)"
means the publishers of the Guide for Plant Appraisal.
"Crown"
means area of the tree above the ground, measured in mass, volume, or area extending from the trunk and including the branches, stems, leaves, and reproductive structures.
"Crown Area"
means the average area in square feet that the tree crown covers (see Figure 16.32.010-1).
Figure 16.32.010-1 - Measuring Crown Area
"Cutting"
means the felling or removal of a tree, or any procedure that naturally results in the death or substantial destruction of a tree. Cutting does not include normal trimming or pruning but does include topping of trees.
"Damaged tree"
means a tree that is injured or knocked down by human activity to the extent that mortality or serious deterioration is likely to occur.
"DBH"
means the diameter at breast height.
"Dead tree"
means a tree that is dead or has been damaged beyond repair or where not enough live tissue, green leaves, limbs, or branches exist to sustain life.
"Diameter at breast height" or "DBH"
means the measurement of mature trees as measured at a height 4.5 feet above the mean ground level at the base of the tree (Figure 16.32.010-2A). The DBH may be determined by measuring the circumference of the tree trunk 4.5 feet above the mean ground level at the base of the tree and dividing by 3.14. Trees existing on slopes are measured at the lowest point of ground at the base of the tree (Figure 16.32.010-2B). When the trunk branches or splits less than 4.5 feet from the ground, measure the smallest circumference below the lowest branch and divide by 3.14 (Figure 16.32.010-2C). For multi-stemmed trees, the size is determined by measuring all the trunks, and then adding the total diameter of the largest trunk to one-half the diameter of each additional trunk. A multi-stemmed tree has trunks that are connected above the ground and does not include individual trees growing close together or from a common root stock that do not have trunks connected above the ground (see Figure 16.32.010-2).
Figure 16.32.010-2 - Measuring Diameter at Breast Height
"Drip line"
means the perimeter measured on the ground at the outermost crown by drawing an imaginary vertical line from the circumference of the crown, straight down to the ground below.
"Dying tree"
means a tree that is diseased, infested by insects, deteriorating, or rotting, as determined by a professional certified in the appropriate field, and that cannot be saved by reasonable treatment or pruning, or a tree that must be removed to prevent the spread of infestation or disease to other trees.
"Hazardous tree"
means a tree or tree part that presents a public safety hazard or poses imminent danger to property as determined by an ISA Qualified Tree Risk Assessor, and such hazard or danger cannot reasonably be alleviated by treatment or pruning.
"Healthy tree"
means a tree that is rated by a professional with expertise in the field of forestry or arboriculture as being in fair or good health condition using International Society of Arboriculture (ISA) Best Management Practices and the rating system in this chapter.
"Invasive species"
means a tree, shrub, or other woody vegetation that is on the Oregon State Noxious Weed List or listed on the Milwaukie Invasive Tree List in the Public Works Standards.
"ISA"
means the International Society of Arboriculture.
"ISA Best Management Practices"
means the guidelines established by ISA for arboricultural practices for use by arborists, tree workers, and the people who employ their services.
"Major tree pruning"
means the trimming or removal of 20% or more of the live crown, or removal of or injury to roots within a radial distance from the tree of six times the tree's DBH or over 25% of the root protection zone (see Figure 16.32.042.G.1.b) during any twelve-month period.
"Minor tree pruning"
means the trimming or removal of less than 20% of the live crown, or removal of or injury to roots beyond a radial distance from the tree of six times the tree's DBH or less than 25% of the root protection zone (see Figure 16.32.042.G.1.b) during a twelve-month period.
"NDA"
means Neighborhood District Association.
"Noxious weed"
means a terrestrial, aquatic, or marine plant designated by the State Weed Board under ORS 569.615.
"Owner"
means any person who owns land, or a lessee, agent, employee, or other person acting on behalf of the owner with the owner's written consent.
"Park tree"
means a tree, shrub, or other woody vegetation within a City park.
"Person"
means any natural person, firm, partnership, association, social or fraternal organization, corporation, estate, trust, receiver, syndicate, branch of government, or any other group or combination acting as a unit.
"Private tree"
means a tree, shrub, or other woody vegetation on land not owned or maintained by the City and the trunk of the tree does not cross a public right-of-way or public property line.
"Public agency"
means any public agency or public utility as defined in ORS 757.005, or a drainage district organized under ORS Chapter 547.
"Public tree"
means a tree, shrub, or other woody vegetation on land owned or maintained by the City, but does not include a tree, shrub, or other woody vegetation in the right-of-way.
"Right-of-way"
means an area that allows for the passage of people or goods. Right-of- way includes passageways such as freeways, pedestrian connections, alleys, and all streets. A right-of-way may be dedicated or deeded to the public for public use and under the control of a public agency, or it may be privately owned. A right-of-way that is not dedicated or deeded to the public is usually in a tract or easement.
"Shrub"
means any plant with multiple woody stems that does not have a defined crown and does not grow taller than a height of 16 feet.
"Street tree"
means a tree, shrub, or other woody vegetation on land within the right-of- way. When any portion of the trunk of a tree crosses a public right-of-way line at ground level, it is considered a street tree.
"Street Tree List"
is the list of tree and shrub species approved by the City for planting within the right-of-way.
"Topping"
means the pruning practice used to reduce tree height by cutting to a predetermined crown limit without regard to tree health or structural integrity. Topping does not include acceptable pruning practices as described in the American National Standards Institute (ANSI) "A-300 Pruning Standards" and companion "Best Management Practices" for tree pruning" published by the International Society of Arboriculture, such as size reduction, utility clearance, or risk mitigation to remove a safety hazard, dead or diseased material. Topping is considered "tree removal".
"Tree"
means any living woody plant characterized by one main stem or trunk and many branches, or a multi-stemmed trunk system with a defined crown, that will obtain a height of at least 16 feet at maturity.
"Tree Board"
means the City of Milwaukie Tree Board.
"Tree canopy"
means the aggregate or collective tree crowns.
"Tree Fund"
means the Tree Fund as created by this chapter.
"Tree removal"
means the cutting or removal of 50% or more of the crown, trunk, or root system of a plant, the uprooting or severing of the main trunk of the tree, topping, or any act that causes, or may reasonably be expected to cause the tree to die as determined by an ISA Certified Arborist.
"Unhealthy tree"
means a tree that is rated by a professional with expertise in the field of forestry or arboriculture as being in poor or very poor/dead health condition using International Society of Arboriculture (ISA) Best Management Practices and the rating system in this Chapter.
"Urban forest"
means the trees that exist within the City.
"Urban Forest Management Plan"
is the management plan adopted by City Council for the management of the City's urban forest.
"Urban Forester"
means the Urban Forester of the City of Milwaukie, or designee.
"Utility"
is a public utility, business, or organization that supplies energy, gas, heat, steam, water, communications, or other services through or associated with telephone lines, cable service, and other telecommunication technologies, sewage disposal and treatment, and other operations for public service.
(Ord. 2247, 1/21/2025)
A. 
City Manager
1. 
The City Manager is authorized to administer and enforce the provisions of this chapter.
2. 
The City Manager is authorized to adopt procedures and forms to implement the provisions of this chapter.
3. 
The City Manager may delegate as needed any authority granted by this chapter to a designee as deemed appropriate by the City Manager.
B. 
City Authority
The City has the ultimate authority to:
1. 
Interpret the provisions of Chapter 16.32 and determine whether code criteria have been met.
2. 
Establish conditions of permit and land use approval to ensure Chapter 16.32 is properly implemented.
3. 
Create rules and procedures as needed to implement Chapter 16.32. Rules and procedures may include, but are not limited to:
a. 
City of Milwaukie tree lists;
b. 
Tree protection standards, specifications, and procedures;
c. 
Tree planting standards, specifications, and procedures;
d. 
Tree establishment and maintenance standards, specifications, and procedures;
e. 
Performance bonding, letters of credit, and cash assurances to help ensure proper tree protection, planting, and establishment;
f. 
Tree protection inspections and oversight;
g. 
Soil protection inspections and oversight;
h. 
Performance path tree protection standards and specifications;
i. 
Performance path soil volume standards and specifications; and
j. 
Fees for permit applications, reviews, mitigation, inspections, and violations.
(Ord. 2247, 1/21/2025)
A. 
Establishment
A City Tree Fund is hereby established for the collection of any funds used for the purpose and intent set forth by this chapter.
B. 
Funding Sources
The following funding sources may be allocated to the Tree Fund:
1. 
Tree permit revenue;
2. 
Payments received in lieu of required and/or supplemental plantings;
3. 
Civil penalties collected pursuant to this chapter;
4. 
Agreed-upon restoration payments or settlements in lieu of penalties;
5. 
Sale of trees or wood from City property;
6. 
Donations and grants for tree purposes;
7. 
Sale of seedlings by the City; and
8. 
Other monies allocated by City Council.
C. 
Funding Purposes
The Tree Board will provide recommendations to the City Council during each budget cycle for how the fund will be allocated. The City will use the Tree Fund for the following purposes:
1. 
Expanding, maintaining, and preserving the urban forest within the City;
2. 
Planting and maintaining trees within the City;
3. 
Establishing a public tree nursery;
4. 
Supporting public education related to urban forestry;
5. 
Assessing urban forest canopy coverage; or
6. 
Any other purpose related to trees, woodland protection, and enhancement as determined by the City Council.
(Ord. 2247, 1/21/2025)