Current Work

Current work

Next steps in the project

Area near Sea-Tac where there has been tree removal and replanting.

Area near Sea-Tac where there has been tree removal and replanting.

One hundred seventy-four trees on public and private property have been identified for removal. The trees either currently obstruct the airport’s airspace or will soon obstruct the airport’s airspace. The Port is removing these trees in 2020/2021.

The 174 trees represent a significant decrease from the initial number of trees identified by the Port as obstructions requiring removal. Based upon earlier public comment and Commission guidance, the Port completed a comprehensive re-analysis of the airport’s airspace requirements in consultation with the Federal Aviation Administration (FAA). The re-analysis led the Port to modify its guidelines for tree removal to emphasize runway surfaces impacting primary flight operations, rather than emphasizing every runway surface subject to FAA obstruction guidelines.

The trees identified for removal are on Washington State Department of Transportation (WSDOT) property, public right of way, school district property, Port of Seattle property and private property. Approximately 60% of the trees lie within WSDOT’s current and future SR 509 right of way.

The Port will substantively comply with all applicable federal, state and local requirements to the extent practicable; plant up to four trees for every tree removed; abide by critical area ordinances for trees in wetlands and buffer areas; and implement actions according to the State Environmental Policy Act (SEPA).

Obstruction removal summary

Jurisdiction/ Property Ownership1 Number of Obstructions Notes
Port 6 Includes two obstructions in critical areas (one in a wetland and one in the wetland buffer).
WSDOT 104 Obstructions are located on WSDOT right of way for the planned SR 509 extension project.
City of SeaTac Public 46 This category includes 27 obstructions located on Highline School District Property.
Private 10 Obstructions in this category are located on Hillgrove Cemetery and residential properties.
Subtotal 56
City of Burien Public 0
Private 7 Obstructions are located on a single vacant property zoned residential.
Subtotal 7
City of Des Moines Public 1 Obstruction is located on the border of a residential property and city street right of way.
Subtotal 1
Total 174

Site vicinity and locations of obstructions

Map showing site vicinity and locations of obstructions, including all jurisdictions.

Click image to enlarge.


Orange dot


Green diagonal lines

Port of Seattle ownership

Gray diagonal grid

WSDOT SR 509 right of way


light blue

City of Burien

light blue

City of Des Moines

light blue

City of SeaTac

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