HomeMy WebLinkAboutReg 2011-10-17 Item 2 - Presentation - Shoreline Restoration ProjectCity of Tukwila
Jim Haggerton, Mayor
INFORMATIONAL MEMORANDUM
TO:
FROM:
DATE:
SUBJECT
ISSUE
Mayor Haggerton
City Council
Brandon J. Miles, Senior Planner
September 28, 2011
Special Presentation on Shoreline Restoration Project by Bluefield
Holdings on behalf of Seattle City Light.
Representatives from Bluefield Holdings will provide the Council a short presentation on a
shoreline restoration project that will be completed along the Duwamish River on behalf of
Seattle City Light.
BACKGROUND
Bluefield Holdings is planning on completing several shoreline restoration projects within the
lower Duwamish River area. Most of the projects will be located within in the City of Seattle, but
one project will be competed on property owned by the Seattle City Light located within the City
of Tukwila.
Bluefield Holdings offers an interesting business model. Bluefield will complete restoration
projects as part of the Superfund cleanup for the Duwamish Waterway. The company then sells
the credits that they generate from the cleanup to potentially responsible parties at a significant
discount. Essentially, the company is using the market as way to complete restoration project
along the shoreline. The City of Tukwila is not a potentially responsible party.
Representatives from Bluefield Holdings will brief the Council about the company and about the
shoreline restoration project that will occur in the City. The presentation will not take more than
ten minutes.
DISCUSSION
None
RECOMMENDATION
Information only, no action needed by the Council.
ATTACHMENTS
A. Information about Bluefield Holdings
B. Information about the proposed shoreline restoration project in the City of Tukwila
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Duwamish River Habitat Restoration Program
Delridge Transmission Line Right of Way
Tukwila, Washington
October 2011
Background:
The City of Seattle and Bluefield Holdings, Inc. are working on the final conceptual designs for
natural resource habitat projects on City of Seattle owned property along the Duwamish
Waterway. There are 12 properties currently under a master lease to Bluefield Holdings, Inc.
The first phase of habitat construction will be on four parcels three are on Seattle Department
of Transportation property under the Spokane Street Bridge located within the City of Seattle
and one is on Seattle City Light property located in the City of Tukwila on the east bank of the
Duwamish River.
Site History
The Project in the City of Tukwila is adjacent to the existing King County North Winds Weir
restoration project site to the south. Seattle City Light transmission lines on the property and
will remain. A portion of the property is currently used to store power poles but a new pole
yard is being constructed. The habitat project will not begin until Seattle City Light completes
the pole yard move and the City of Seattle has approved the conceptual design.
The existing intertidal portion of the Project site includes rubble, riprap, and predominated
invasive species. Consequently, aquatic habitat in the area is very poor. Industrial
development along the Lower Duwamish Waterway has largely eliminated off- channel habitat
used by estuarine species, resulting in limited rearing and refuge habitat in the existing channel.
Habitat Restoration
The restoration Project in the City of Tukwila will create or restore approximately 2.43 acres of
habitat from lands currently occupied by riprap and un- vegetated upland. Combined, with the
adjacent King County North Winds Weir restoration project, would create more than 6.0 acres
of total habitat restoration. The restoration will create a new off- channel inlet which will provide
refuge and feeding opportunities for out migrating salmonids, juvenile English sole, shorebirds
and waders. The restored uplands adjacent to the created inlet will provide food and refuge for
a broad range of bird groups.
A long -term stewardship fund will be established to continue all appropriate maintenance of the
Project to ensure the longevity of the fully functioning habitat.
Construction activities will include removal of existing rubble and debris from the shoreline,
excavation of upland soils to create new intertidal area, and replacing riprap where possible
with fish- friendly materials including sediment, fish mix gravels, and anchored large woody
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debris. The new off- channel inlet will maximize the length and width of intertidal habitat within
the confines of the existing utilities and infrastructure at the Site.
The current face of the property running parallel with the Duwamish River will be sloped back
and the riprap face of the shoreline will be replaced with larger natural boulders, cobble
material, and anchored large woody debris to the extent practicable within slope and
hydrodynamic limitations. For the purposes of hydraulic stability during high flow storm events,
some rock (rip rap or quarry spalls) may be installed under more fish friendly materials as
appropriate. The Site will be finished with additional soil cover, the planting of upland
vegetation, and planting and seeding of a tidal marsh.
Following initial construction of the Project, operations, maintenance and monitoring activities
will be conducted to enhance the survivability of newly established plants, as well as to evaluate
the performance of the newly created habitat. The goal of the Project is to create a self
sustaining habitat that will complement any existing natural resources and further enhance the
natural ecosystem and support native marsh species.
Public Outreach for Seattle City Light /Delridge Transmission Line
As with any development, the permitting phase of the project will carry with it a specific public
involvement and comment process. However, it is important to the City of Seattle and a
requirement of Bluefield Holdings, Inc. lease that the draft designs be reviewed by key
stakeholders before they are submitted for construction permitting. Seattle City Light will then
report to the Seattle City Council on the outreach to key stakeholders, approve the conceptual
design and then it will enter the permitting phase.
The designs have been developed to maximize the amount of natural, salmon friendly habitat in
keeping with the requirements of the Natural Resource Trustees for the Duwamish Waterway.
Both land and water public access will be included in the project designs where possible.
Public access could include viewing from the North Winds Weir area and signage (both for
upland viewers as well as toward the water for water borne viewers).
Public access will not be possible in areas where there are safety concerns or where public
access could lessen the ecological benefits of natural habitat for endangered species.
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