A Significant Tree is defined as any tree that has a diameter equal to or greater than 6 inches measured at 4.5 feet above the ground.
An Exceptional Tree is defined as any tree that has a diameter equal to or greater than 30 inches, and they are valued at 1.5 times their diameter.
Significant Trees that meet the requirements of one of the special circumstances under the Tree Protection Ordinance do not require mitigation for a tree removal permit.
Special circumstances include, but are not limited to:
- the tree is assessed as 100% dead by a Certified Arborist,
- the tree is assessed as dangerous by a Certified Arborist,
- emergency circumstances (such as the tree has uprooted and is in danger of falling onto people or property),
- the tree poses significant negative impacts on an existing structure,
- removing the tree would benefit other existing Significant Trees on the property.
Tree Removal Application Requirements
Photos are required for all tree removal applications. At a minimum, all tree removal applications shall include:
- A photo clearly showing the entire tree including its crown.
- A photo showing the diameter measurement of the tree.
Please refer to the Tree Protection Ordinance Regulations for a complete list of the special circumstances and the required documents for each type of circumstance. Incomplete applications will not be reviewed until all missing information has been submitted.
Property owners may submit tree removal applications but a Certified Arborist or another professional assessment may be required. For example, a Certified Arborist is required for trees that are dead or dangerous. A Professional Engineer may be required for applications to remove a tree that poses a significant impact on a structure. The City Arborist and other Urban Forestry staff cannot serve as Certified Arborists for private tree removals. Reputable Certified Arborists can be found, and their credentials verified, via the Massachusetts Arborists Association and/or the International Society of Arboriculture:
Massachusetts Arborists Association: https://massarbor.org/directory.php
International Society of Arboriculture: https://www.treesaregood.org/
Tree Removal Mitigation Requirements
When removing a Significant Tree that does not meet the requirements of a special circumstance under the Tree Protection Ordinance, mitigation will be required. Mitigation can be fulfilled through planting on the property, payment to the City’s Tree Replacement Fund, or a combination of planting and payment. Planting Replacement Trees can significantly reduce mitigation payment. The remaining mitigation payment after planting Replacement Trees is calculated by subtracting the diameter of the Replacement Tree from the Significant Tree to be removed, dividing by two, and multiplying by the cost per inch to plant a tree under the City’s most recent tree planting and maintenance contract inclusive of purchasing, planting, watering, and maintaining trees for a period of 5 years. The current cost is $850 per inch. If there are more Replacement Trees than Significant Trees to be removed, the additional diameter of the Replacement Trees is accounted for in the mitigation payment.
A mitigation payment is required for all Significant Trees removed where an insufficient quantity of
Replacement Trees is provided. A 10% mitigation payment applies to property owners who qualify for the City’s residential real estate property tax exemption.
For mitigation requirements associated with Large Projects, or any project which requires a special permit under §§ 4.26.l - 4.26.3, §19.20, §11.12.1, §11.12.2, or §11.12.3 of the Zoning Ordinance, please refer to the complete Tree Protection Ordinance language.
Calculating Tree Removal Mitigation
The formula for calculating a mitigation payment is as follows:
Mitigation Payment = [[(diameter in inches of Significant Tree – diameter in inches of Replacement Tree)/2] – diameter of any additional Replacement Trees] x $850
Please see below for examples of mitigation based on different sizes of Significant Trees and Replacement Trees.
Remove a 6” tree and plant 0 Replacement Trees
Mitigation Payment = 6” x $850/inch
Mitigation Payment = $5,100
Mitigation Payment with Residential Exemption = $510
Remove a 6” tree and plant one 2” Replacement Tree
Mitigation Payment = [(6” – 2” Replacement Tree)/2] x $850/inch
Mitigation Payment = [4”/2] x $850/inch
Mitigation Payment = 2” x $850/inch
Mitigation Payment = $1,700
Mitigation Payment with Residential Exemption = $170
Remove a 6” tree and plant two 2” Replacement Trees
Mitigation Payment = [[(6” – 2” Replacement Tree)/2] – 2” additional Replacement Tree] x $850/inch
Mitigation Payment = [(4”/2) – 2” additional Replacement Tree] x $850/inch
Mitigation Payment = (2” – 2”) x $850/inch
Mitigation Payment = $0
Mitigation Payment with Residential Exemption = $0
Remove 6” and 10” trees, plant one 2” Replacement Tree
Mitigation Payment = [[(6” – 2” Replacement Tree)/2] + 10”] x $850/inch
Mitigation Payment = [(4”/2) + 10”] x $850/inch
Mitigation Payment = (2” +10”) x $850/inch
Mitigation Payment = 12” x $850/inch
Mitigation Payment = $10,200
Mitigation Payment with Residential Exemption = $1,020
Remove 6” and 10” trees, plant two 2” Replacement Trees
Mitigation Payment = [[(6” – 2” Replacement Tree)/2] + [(10” – 2” Replacement Tree)/2]] x $850/inch
Mitigation Payment = [(4”/2) + (8”/2)] x $850/inch
Mitigation Payment = (2” + 4”) x $850/inch
Mitigation Payment = 6” x $850/inch
Mitigation Payment = $5,100
Mitigation Payment with Residential Exemption = $510
Remove 32” tree, plant 0 Replacement Trees
Mitigation Payment = (32” x 1.5 Exceptional Tree multiplier) x $850/inch
Mitigation Payment = 48” x $850/inch
Mitigation Payment = $40,800
Mitigation Payment with Residential Exemption = $4,080
Remove 32” tree, plant four 2” Replacement Trees
Mitigation Payment = Replacement Tree]/2] – 6” additional Replacement Trees] x $850/inch
Mitigation Payment = [[(48" – 2" Replacement Tree]/2] – 6” additional Replacement Trees] x $850/inch
Mitigation Payment = [[(46”/2) – 6” additional Replacement Trees] x $850/inch
Mitigation Payment = (23” – 6”) x $850/inch
Mitigation Payment = 17” x $850/inch
Mitigation Payment = $14,450
Mitigation Payment with Residential Exemption = $1,445
Tree removal applications where mitigation will be fulfilled through planting require the following Replacement Tree information:
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The size (caliper) of Replacement Tree(s),
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Species of the Replacement Tree(s)
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Planned planting location (plan or photos),
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Anticipated planting date, and
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A 5 year care and maintenance plan. The City has provided a default care and maintenance plan under the Useful Documents and Resources section of this webpage.
Replacement Trees will continue to be identified as Replacement Trees for a period of 10 years after they are planted. A tree removal permit is required to remove any Replacement Tree, regardless of its size. The species of Replacement Tree may be selected by the property owner. Species of shrubs such as arborvitae may not be planted to fulfill mitigation requirements. Please see the City’s tree planting list for species recommended by the Urban Forestry Division. All Significant Tree documentation and any Replacement Tree documentation and/or mitigation payment must be submitted before a tree removal permit can be issued.
Mitigation payments can be made via check dropped off at the DPW main office at 147 Hampshire St or online through the permitting portal. Checks should be made out to “The City of Cambridge”, please include the tree removal application number in the memo line. Payments completed online are subject to convenience fees.