Port Property

Port property

Photo showing off-site area used for Site P-5 mitigation

Off-site area used for Site P-5 mitigation.

Below are the six Port of Seattle areas where invasive species, tree removal, site preparation and replanting work is nearly complete. Click on the site title bars below to learn more about each site’s environmental characteristics and the number of trees removed and replanted. The Port replanted more than four times as many trees and shrubs as it removed and is on the second year of monitoring the success of its new plantings.

Work on sites P-1, P-2, P-3 and P-6 was completed in the fall of 2017. For sites P-4 and P-5, the Port Commission called for more community engagement before determining the removal and replanting approach. Why? Most over-height conifers were located within those sites, and both sites are also adjacent to residential properties. Using input submitted at a community workshop and through an online open house, the Port developed a preferred approach for sites P-4 and P-5 that reflected the community’s feedback. The approach called for removing only existing obstructions, restoring the sites with a low-growing forest and planting an additional 3.5 acre off-site location with tall-growing native conifers south of sites P-4 and P-5 where the conifers would not become future obstructions. The off-site location included removing substantial invasive species cover and is located adjacent to a residential area where the restoration provides a visual aesthetic.

Please note: On Site P-5, six trees have penetrated the airport’s airspace since the work concluded and will be removed in 2020/2021. Visit the Other Public Property tab for the locations of the six trees.

Photo showing off-site area used for Site P-5 mitigation

Off-site area used for Site P-5 mitigation.

Trees removed on Port property

Map showing site vicinity and locations of trees removed from Port property.

Click image to enlarge.

Legend

Orange dot

Obstructions removed on Port property

Green diagonal lines

Port of Seattle ownership

Gray diagonal grid

WSDOT SR 509 right of way

Jurisdiction

light blue

City of Burien

light blue

City of Des Moines

light blue

City of SeaTac

Site P-1

Removed: 56 trees

Replanted: 118 trees

This 2.5-acre tract is the only Port site located north of Sea-Tac Airport and includes a wetland, wetland buffer and steep slopes. In addition to five tree obstructions and 51 potential tree obstructions, the site contained invasive species (including English ivy, common holly and Himalayan blackberry).

Photo showing replanting as part of the Site P-1 mitigation.

Site P-2

Removed: 239 trees

Replanted: 76 trees

This 16.5-acre site is located west of the airport near the Port’s west side office. This area is adjacent to two wetlands and contains wetland buffers and steep slopes. In addition to 82 tree obstructions and 157 potential tree obstructions, the site contained invasive species including dense Himalayan blackberry and Scotch broom.

Photo showing replanting as part of the Site P-2 mitigation.

Site P-3

Removed: 298 trees

Replanted: 1363 trees

This site, located south of the airport and east of the Tyee mitigation site, includes Site P-3a (24 acres) to the north and Site P-3b (35 acres) to the south. Both sites include wetlands, wetland buffers and steep slopes, though the wetland complexes within Site P-3a are much more contiguous than in Site P-3b. Site P-3b also contains a stream and stream buffer. Site P-3a contained 89 existing and 158 potential obstructions; Site P-3b contained 26 existing and 25 potential obstructions. Site P-3b also contains a fair amount of ornamental landscape areas that were once part of the Tyee Valley Golf Course.

Photo showing replanting as part of the Site P-3 mitigation.

Site P-4

Removed: 38 trees

Replanted: 193 trees on-site
+ 94 trees off-site

This 0.7-acre tract is located south of the airport on vacant land adjacent to S. 200th St. The site contained 23 obstructions and required removing 15 additional trees to enable access and obstruction removal. The site is partially forested with a dominant invasive understory including ivy, blackberry, nightshade and hedge bindweed. Replanting actions were performed on-site with low-growing native varietals, along with tall-growing native trees off-site where they will not become obstructions in the future.

Photo showing replanting as part of the Site P-4 mitigation.

Site P-5

Removed: 134 trees

Replanted: 989 trees on-site
+ 483 trees off-site

This 3.5-acre tract south of the airport contained 94 obstructions and required removing 40 additional understory trees to enable access and obstruction removal. The forested site contains interspersed native (Oregon grape, salal, sword fern) and invasive (including English ivy, common holly and Himalayan blackberry) understory shrubs and ground cover. Replanting actions were performed on-site with low-growing native varietals, along with tall-growing native trees off-site where they will not become obstructions in the future.

Photo showing replanting as part of the Site P-5 mitigation.

Site P-6

Removed: 18 trees

Replanted: 54 trees

This 16-acre site is located to the south of the airport and to the west of Sites P-3a and P-3b; the site contained 18 existing obstructions.

Photo showing replanting as part of the Site P-6 mitigation.


Go To Next Page