Blair Waterway Berth and Channel Deepening and Nearshore Habitat Restoration

Abstract: The Port of Tacoma (Port) and the Northwest Seaport Alliance (NWSA) are in the process of modernizing the Blair Waterway and associated deep-draft container terminal facilities in Tacoma, Washington, to accommodate newer and larger container vessels that are being used by the ocean carriers. As part of the modernization effort, a deepened waterway within the existing federal navigation channel and berthing areas are required. The U.S. Army Corps of Engineers (USACE) is overseeing and managing the deepening of the Blair Waterway federal navigation channel, and the Port and NWSA are responsible for the deepening of the container terminal facility berthing areas, including Husky Terminal and Washington United Terminals, located on the Blair Waterway. In addition to the berth-deepening work at the terminals, the Port is exploring options to beneficially reuse suitable dredged material to create nearshore habitat improvements at a nearby shoreline location—referred to as the East Commencement Bay Habitat Opportunity (ECHO)—as well as at other potential shoreline locations within Commencement Bay.

Deepening the berth areas at the existing container facilities to accommodate larger and deeper-draft container vessels will require installation of toe wall structures at the berth areas to support existing underpier slopes, after which the berth areas will be dredged to the deeper required operational elevations. In addition to the design and construction of the berth-deepening elements, the Port is also managing sediment characterization of the berth areas and the federal navigation channel to identify suitability of material for beneficial reuse, open-water disposal, or disposal at an upland landfill facility. Results from the sediment characterization efforts will inform development of an innovative dredged material management approach for sediments removed within the berth areas and the federal navigation channel. In addition to the Port exploring nearshore habitat restoration and enhancement opportunities at the ECHO site, the Port will also coordinate with project stakeholders (USACE, local tribes, state and local regulatory agencies, and the public) to identify other options for beneficial reuse of suitable dredged material to support nearshore habitat restoration and development of upland Port-owned properties. Material identified as unsuitable for open-water disposal or beneficial reuse will be taken to an upland landfill facility for final disposal.

This paper will provide a general overview of the approach for development of the berth area and federal navigation channel deepening design and sediment characterization programs, describing the associated complexities, anticipated challenges, and mitigation measures that will be developed to successfully design and implement the project. Specific complexities and challenges that will be addressed include integrated project permitting, design and construction sequencing, schedule planning, dredged material management planning, and obtaining support from key project stakeholders.

How does this project / topic contribute to the advancement of the industry and profession?: This project provides an example of a large-scale navigation channel and berth-deepening effort that allows one of the largest container ports in North America to modernize two container facilities while also developing a dredged material management approach that maximizes the opportunities for beneficial reuse and habitat restoration.

Does the project / topic implement new and innovative techniques, materials, technologies, and delivery methods?: The innovative element of this project will include development of a dredged material management approach that considers project planning, sequencing for implementation, environmental quality of dredged sediment, and Port and stakeholder interests to optimize the opportunities to beneficially reuse suitable materials for habitat restoration and Port property improvements.

What was the most challenging aspect of your project / topic and how did you handle it to ensure success?: The most challenging aspect of this project includes successful coordination between key project stakeholders (USACE, local tribes, state and local regulatory agencies, and the public) to meet stakeholder requirements and to optimize project outcomes in the best interests of all parties involved.

Who is the target audience for this paper?: The target audience is port environmental and engineering directors, project managers, regulatory agencies, and professional services design firms who have interest in developing similar innovative approaches for designing complex dredging and material management projects with varying stakeholder interests and multiple project funding sources.