Office of the Mayor
City of Seattle
Bruce A. Harrell, Mayor
Executive Order 2023-03: One Seattle Tree Plan: Growing and Fostering an Equitable Tree Canopy on Public Land
An Executive Order directing City departments to protect and grow our City's tree canopy by developing and enacting specific actions to prepare for and mitigate the impacts of climate change and invasive pests on trees found within City of Seattle
property to address equity concerns and to protect our environment.
WHEREAS, urban trees, forests, and riparian ecosystems are critical green infrastructure that provide essential benefits by helping to cool our city during increasing heatwaves, lessen the urban heat island effect, mitigate stormwater runoff, sequester
carbon, filter other pollutants, provide habitat for urban wildlife, improve physical and mental health for residents, and, in ways that are relevant to location and species, maintain cultural heritage and Tribal identity; and
WHEREAS, recent studies have shown that Seattle's tree canopy cover has decreased between 2016 and 2021, led by declines in tree canopy within our City parks and Neighborhood Residential Zones; and
WHEREAS, there are significant equity concerns as marginalized communities across Seattle disproportionately lack tree canopy. Data shows Black, Indigenous, and People of Color (BIPOC) communities tend to have lower canopy coverage (between 10% and 20%)
compared to predominately affluent, white communities. Specific under-treed areas of the city include Rainier Valley, the Lower Duwamish, and Georgetown; and
WHEREAS, Seattle has a goal of increasing its tree canopy cover from 28.1% as of 2021 to at least 30% by 2037, as well as improving tree health and the equitable distribution of trees throughout the city to support healthy communities and improve
resiliency to climate change; and
WHEREAS, climate change is creating hotter, drier environments. Changing seasonal precipitation creates drought stress that threatens the health of trees and makes it difficult for younger trees to become established; and
WHEREAS, many of the trees planted in Seattle are neither native nor climate adapted, are nearing the end of their life span, or some combination thereof, making them less able to withstand extended summer drought; and
WHEREAS, introduced disease and pests are significant threats to the City's tree canopy in the coming decades. Commerce and climate change continue to facilitate introduction of novel species into native ecosystems and the urban tree canopy. The Emerald
Ash Borer, which has decimated Ash trees across the country, was discovered in Portland in 2022 and has the potential to wipe out Seattle's entire Ash tree population. Two other dangerous pests, the Bronze Birch Borer and Spongy Moth, have already
arrived in Seattle. While healthy trees can better ward off pests and disease, trees stressed from drought and higher temperatures are more susceptible to damage and mortality; and
WHEREAS, the City of Seattle is the property owner and steward of over 119,000 acres of forested ecosystems outside of city limits, including the Cedar River and South Fork Tolt River watersheds and Skagit River dams. Forests in these watersheds filter
the region's drinking water, clean air, sequester carbon, and provide essential habitat for wildlife and other plants that must also adapt to the impacts of changing climate conditions and wildfire threat; and
WHEREAS, the seven City departments responsible for properties with trees and forests (SCDI, SDOT, SCL, SPU, SPR, FAS, and CEN) currently report to OSE on a quarterly basis each year the number of trees removed on city property and the number of trees
planted by City departments, and OSE works with the departments each year to incorporate this data into an Urban Forestry Progress Report.
NOW, THEREFORE, I, Bruce A. Harrell, Mayor of Seattle, in recognition of the existing and coming threats to trees on City of Seattle property, order City departments to:
1. Grow the City's urban tree canopy and address inequity within the canopy through the following:
a. Create a One Seattle Tree Fund, collected from fee-in-lieu payments from developers and private property owners in accordance with Seattle's Tree Protection Code, SMC 25.11.
b. Target new tree plantings in areas with:
Low canopy cover, specifically BIPOC communities and communities most impacted by urban heat islands and unmitigated stormwater.
High-opportunity areas, such as publicly owned rights-of-way and parks.
c. Expand public-private partnerships to support new, innovative funding mechanisms to maintain and grow Seattle's urban forest on public lands and in Seattle's rights of way.
In addition to the successful Green Seattle Partnership, explore new engagement with philanthropy, private businesses, and NGOs.
Explore a partnership between Seattle Parks and Recreation and the Seattle Parks Foundation, and in collaboration with other relevant departments, to determine the feasibility of a carbon crediting system to fund urban forestation projects,
particularly in neighborhoods with a historic tree deficit.
Where feasible, leverage federal and state carbon mitigation funding sources to increase canopy growth and maintenance.
d. Replace every healthy, site-appropriate tree removed from City property within city limits with a minimum of three trees; replace every tree on City property within city limits removed because it has died or is otherwise hazardous or invasive
with a minimum of two trees. New and replacement trees shall meet the following requirements:
To the extent practicable, tree selection should consider native species, indigenous or cultural significance to the area in which it is being planted, or a climate adaptive species from a similar ecosystem that will maximize mitigation of
carbon and stormwater runoff and be resilient to climate change and pests.
Follow "Right Tree, Right Place" principles, ensuring mature trees will be an appropriate width and height for their location and will not damage existing infrastructure or structures, including underground utilities.
Wherever feasible, departments should choose the largest tree species (at maturity) appropriate for the site.
Replacement plantings shall be planted within two years of removal or demise.
These tree replacement requirements supersede those established in Executive Order 03-05: Tree Replacement.
e. Remediate unhealthy trees and trees creating conflicts through department staff assessment. If a tree cannot be assisted, replacement species selection will be made in accordance with the replacement requirements above.
f. Maximize survival during the first five years of planting, when trees are most vulnerable, by ensuring that all trees that are replaced have a robust maintenance plan.
2. Steward City-managed forested watersheds outside of urban areas for the long-term provision of ecosystem services to the communities we serve, based on principles of diversity, equity, and inclusion and best available scientific knowledge.
3. Report on urban area tree canopy expansion and protection progress through the annual Urban Forestry Progress Report and an additional biannual budget and staff report. The Progress Report will include additional data reported to OSE by the
seven City departments responsible for properties with trees (SCDI, SDOT, SCL, SPU, SPR, FAS, and CEN).
The reporting will include, at a minimum, the following metrics:
o An estimate of the number of trees and/or canopy acreage each department is responsible for maintaining;
o Number of trees removed;
o Number of trees that have died, along with cause of death; and
o Number of trees replanted, contextualized by general species selection criteria.
Each of the metrics above will include a breakdown of trees in equity priority neighborhoods and trees outside those areas, as well as a breakdown of evergreen and deciduous species.
The annual Progress Report will also include department plans for the coming year for implementation of the Tree Canopy Equity and Resilience Plan, including plans for tree maintenance and increasing canopy across City properties.
Additionally, OSE will develop a biannual budget and staff report detailing resources dedicated to urban forestry, by department. This report will communicate One Seattle Urban Forestry investments to protect, care for, and expand healthy and
resilient trees on public land.
Inquiries regarding this Executive Order should be directed to Director of Policy, Dan Eder, at Dan.Eder@seattle.gov.
Dated this 7th day of March, 2023.
Bruce A. Harrell
Mayor of Seattle