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Project Summary

Duwamish River Estuary Intertidal Wetlands

Northwest Regional Map


1. Project Identification

Name Duwamish River Estuary Intertidal Wetlands
Region Northwest
State Washington
Location Duwamish Waterway, Seattle WA
Date of this update  

2. Problem(s) addressed (e.g. habitat degradation, species of fish (juvenile salmon, etc. (use categories from Lessons Learned Report)

Habitat Degradation

3. Project Description (Please include qualitative information, e.g. acres of habitat restored, miles of steam reopened to migration, and legislative authorization, e.g. WRDA, ISTEA, CWA/NEP, CZMA, etc.)

Local geologic conditions in the Pacific Northwest have limited the extent of broad, flat coastal areas considered essential for modern human development. This topography has directly influenced the location and manner in which commercial development in the areas surrounding Seattle, Washington's Puget Sound has evolved, thereby placing significant development pressures on the coastal wetlands and other coastal habitats of the Puget Sound Estuary.

The Port of Seattle, located in the Duwamish River estuary within Puget Sound, provides an example of the industrial history in this area. The Duwamish River provides a passageway to the inland portions of the state, and thus has been an area of heavy industrial development. Concrete, glass, steel, and lumber factories, and construction and barge companies have all been a part of its economic fabric. This development, while playing a significant role in the economic expansion of the Seattle region, has taken a heavy environmental toll. The developmental history of the Duwamish Estuary has resulted in the loss of approximately 98% of its former intertidal marshes and mudflats. These habitats are critical to juvenile salmon and many other species of aquatic and terrestrial wildlife, and their loss represents a serious threat to the ecological integrity of both the Duwamish River Estuary and the greater Puget Sound. Despite this heavy loss, the Duwamish river system continues to provide remnants of valuable habitat function within a highly urbanized area. The river still supports a limited heron rookery and salmon fishery, however, that productivity could be increased if additional habitat were established.

This Coastal America project has remediated some of the impacts of historical industrialization with enhanced and restored environmental features. Three sites along the Duwamish River were identified for initial restoration; the Turning Basin, the General Services Administration (GSA) site, and Terminal 105. These three areas were chosen based on their availability and suitability for restoration and their potential to show marked improvements in critical habitats with restricted funding. Each project had three basic phases: first, the removal of debris; next, the regrading of the shoreline and bottom sediments to restore appropriate intertidal elevations, and; finally, the reestablishment of a riparian buffer.

There are a number of habitat reconstruction technologies being demonstrated in this group of projects. For example, at the GSA site modified log booms are being used to minimize boat wake impacts along the shoreline. Another is the construction of an intertidal bench on existing rip rap, along with modified rip-rap bank tops to facilitate the development of a more robust riparian buffer that is better able to withstand erosive forces. These projects also have individual education components such as interpretive signs to explain the ecological importance of the features being developed at these sites. Volunteer youth groups were used in the planting of the intertidal and riparian buffer areas, an activity that also had an education component to it, as these volunteers learned about the importance of these small ecological improvements. The restoration of these sites will help to partially restore salmon and other aquatic wildlife populations and their habitat, enhance public access to the river, and improve the quality of life along this active waterfront. The net result is ecological restoration and sustained environmental features along with continued economic development.

These restoration activities have been undertaken under the leadership of the FWS in partnership with the NMFS, the EPA, the COE, the GSA, and the Port of Seattle. The NMFS conducted contaminant sampling and evaluation, review and analysis of monitoring data. The EPA providing overall federal coordination, baseline sediment sampling, and development and facilitation of monitoring and sampling plans for project evaluation. The COE for technical assistance in engineering, design and construction, baseline sediment sampling and analysis and the administration of permit requirements. The General Services Administration (GSA) was the facilities manager of the GSA site. The Port of Seattle also played a major role as the lead nonfederal sponsor.

4. Goals/Benefits (quantify where possible using measures of success list)

About three acres of intertidal nearshore habitat were restored in a highly industrialized waterway.

Was a cost-benefit study conducted for this project? yes/no If yes, provide a summary of findings.

No

5. Partners (include each participant's responsibilities - funding, permitting, etc.)

6. Funding/Contributions (organization and amount)

7. Legislative authorities used by each participant

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8. Value added by Coastal America Partnership Approach

  1. Would the project have been undertaken by a single agency? (yes or no)

    No, Coastal America facilitated the funding from USFWS to the project.

  2. IF YES: How was the project different as a Coastal America Partnership Project than it would have been as a single agency project? (e.g. size and scope, funding, time frame, etc.)

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9. Project Status

Initiation date 1992
Completion date 1996
Current stage Completed

10. Contacts

11. Any additional information/comments

These were (are demonstration projects. The purpose was to show different restoration techniques that could be implemented in an urban environment. Additionally, we have four years of monitoring data on these sites.

This page was last updated on Saturday, 24-Jun-2000 11:48:48 EDT
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