The purpose of this project is to remove invasive vegetation and plant native plants (primarily trees and shrubs) within the riparian zone of the Duwamish River in partnership with public and private property owners. Ensuring the survival of these plantings through ongoing monitoring and maintenance will also be emphasized. King County WRIA 9 and City of Tukwila staff recently established contact with landowners along the river who are interested in implementing riparian restoration projects. King County intends to work with the City of Tukwila and public and private landowners to coordinate volunteers and restoration crews to remove invasives and plant native plants along the Duwamish to benefit fish, wildlife, water quality, and the people living and working in the area. This work will build on the ongoing progress made controlling common reed (Phragmites australis) and perennial pepperweed (Lepidum latifolium) along the Duwamish River, as well as efforts to control knotweed (Polygonum sp.) upstream on the Green River and on King County levees.

A systematic plan to control knotweed and other regulated weeds (e.g., perennial pepperweed and garlic mustard [Alliaria petiolata]) along the banks of the Duwamish Waterway within the City of Tukwila will be developed. The first year of control will be
undertaken in 2013, after property access is granted. Subsequent years of treatment and monitoring will also be completed, and areas of weed removal will be planted with native plants, focusing on large infestations where natural native plant regeneration is not likely. The third year of treatment and planting for approximately half of the knotweed area is currently not funded.

Targeted restoration will be completed within the Duwamish and Allentown neighborhoods and public lands owned by Seattle City Light and City of Tukwila. In this phase 1, public lands will be targeted for tree canopy restoration by removing invasive plants (primarily Himalayan blackberry, English ivy and clematis) and planting native plants and coniferous trees. At least 8 private landowners have already agreed to participate; adjacent landowners will be prioritized for restoration work.

Much of this project is in the high priority Duwamish estuary 'transition zone' between fresh and salt water, which provides the appropriate range of salinities for juvenile Chinook and chum to transition to salt water. Limited opportunities exist to create shallow and off-channel rearing habitat for juveniles in the transition zone due to residential, commercial and industrial land uses along the river. Where there is no opportunity for setting back banks, a healthy riparian tree canopy will provide shade, insects for juvenile fish to eat, and large wood for later recruitment into the waterway. Existing vegetated banks of the Duwamish River are largely comprised of rip rap and invasive plants, and some deciduous forest. This grant will leverage assistance from the City of
Tukwila, volunteers, and public and private landowners to restore native vegetation and coniferous trees along the Duwamish River in locations that are not suitable for shallow water habitat creation.