As one of only a few locations on the island not having an adequate bypass route for emergency vehicles, Oakes Road was designed to provide a bypass in the event that this section of SR 525 becomes blocked. To offset unavoidable wetland, stream, and buffer impacts associated with the construction of the bypass, a compensatory wetland mitigation plan was designed to support local, state, and federal permitting.
Roadway Design with Unique Environmental Implications
A new, two-lane asphalt roadway, Oakes Road included features such as graded shoulders, drainage ditches and culverts; bioretention and infiltration LID facilities; retaining walls; onsite wetland and stream mitigation; utility relocations; channelization; and signing. The federally-funded project was also unique in that it traverses land parcels containing uncut forests and existing homes which ultimately required establishing an alignment that met objectives while also seeking to minimize property impacts and setbacks from existing structures and private wells. The goal of the mitigation site is to enhance an existing low-functioning wet pasture to a high-functioning wetland with a mosaic of wetland habitats using native plants. Otak led the planning and design of Oakes Road along with the wetland delineation and functional assessment, including coordination of environmental permitting, documentation, and plan installation.
Ongoing work across numerous planning and design projects with the City of Burien has resulted in several regional stormwater facilities to serve redevelopment and growth. With several targeted and city-wide stormwater plans in place, the City of Burien is addressing drainage issues and investing in green infrastructure to support development while protecting local streams. In developing these plans and its subsequent projects, Otak also led community engagement in person and through interactive GIS StoryMaps to ensure an equitable process as well as community and staff buy-in.
Leveraging GIS Data for Ongoing, Equitable Stormwater Improvement
Starting with a master drainage plan for the North East Redevelopment Area (NERA), the City of Burien has expanded its stormwater approach and broader infrastructure development goals. Using hydrologic analysis and hydraulic modeling, the NERA plan included managing existing and future stormwater needs. The plan was implemented through years of design work, including all the way through construction management for regional stormwater facilities. Later, a Stormwater Management Action Plan (SMAP) was developed based on basin-level GIS analyses to protect and improve Miller Creek through green infrastructure and policy changes in the downtown catchment. The broader Burien stormwater master plan goes further to analyze city-wide drainage issues and design system improvements. These actions position the city to reduce flooding and improve water quality for the community.
To integrate current community priorities and ensure consistency with state and regional growth management planning, the Envision SeaTac 2044 Comprehensive Plan was updated to aid decision-making and development for the next twenty years. Otak collaborated closely with City staff to provide inclusive and extensive community engagement to help shape the plan, and we helped guide City leadership review throughout the comprehensive planning process. We also developed a geographic information systems (GIS)-based Equity Index Mapping Tool to help the City understand and expand access to opportunities—housing choices, parks and recreation, healthy foods, transit and transportation choices, social and public services, jobs and economic options, and other quality of life enhancements.
Expanding Communitywide Access to Opportunities, Aided by Geospatial Mapping
Strengthening the community’s identity and planning for anticipated growth and change, the updated SeaTac Comprehensive Plan provides guidance for decision-making and policy with a focus on enhancing community well-being and expanding access to opportunities informed by development of a specific SeaTac Equity Index Mapping Tool. Key growth strategies include expanding multimodal transportation and access to light rail stations, providing a range of housing choices for residents, and enhancing services and infrastructure to support growth and development. The Equity Index Tool helped identify and address inequities within the community to better guide the allocation of resources and focus of policy-making in long-range planning. The comprehensive plan provides elected and appointed officials, city staff, residents, and the business and development communities, with a comprehensive, consistent, equitable, easy to use, and culturally-relevant plan.
A 120-foot replacement for the Kellogg Creek Bridge was needed after being compromised during extreme weather events. The clear span design solved flooding and scour issues from the creek beneath while also protecting a unique, pre-existing fish ladder.
A More Resilient Structure and Sustainable Aquatic Habitat
Because of significant structural issues caused by extreme weather events, Kellogg Creek Bridge included a fast-track approach for the procurement of the design-build team and required quick mobilization and efficiency to meet aggressive construction timeframes. Unusual hydraulics consisting of backwater from the Willamette River resulted in high flows in Kellogg Creek, causing significant scour. The design also enhanced the south bank below the bridge by adding woody debris for fish habitat along with rock revetment for bank stabilization. Otak was the lead design consultant, quality manger, and construction manager for Kellogg Creek Bridge, placing an emphasis on climate change resilience and the sustainability of aquatic habitats.
To provide a more natural open discharge and eliminate a fish barrier from the outfall of Riverton Creek into the Duwamish River, associated flap gates and pipe culverts would need to be removed.
Improved Fish Passage and Pedestrian Bridge
Incorporated into the work was the design of a bridge to carry the Green River Trail over the new Riverton Creek channel. Improvements also include the removal of a portion of an existing concrete retaining wall and of retrofit an existing sheet pile wall that supports Pacific Highway South using soil anchors. Design of a new deep retaining wall supports a private parking lot. Included in stream enhancements was a focus on riparian plantings. In addition to executing the project, the Otak team led updates to previously provided reports and developing plan, specification and estimates (PS&E).
The SR520 Program involved three major design-build projects including a pontoon fabrication contract valued at over $300M, bridge replacement and HOV project at over $800M and highway expansion project at over $350M. Work included three major bus transit stations, signalization, communications, maintenance base and toll systems.
Complete Support for Large Transportation Program Goals
In accordance with WSDOT manuals and guidance documents, the SR520 design build program totaled $4.6B and required significant advising, business and construction support. Otak worked with all partners in developing, implementing and executing initiatives, plans and support for permitting, design and construction delivery. The firm provided eight full time staff in roles ranging from inspection, scheduling and program management to claims, compliance and progress reporting. This included responsibility for all weekly, monthly, and quarterly reporting related to program delivery, finance and executive briefings.
In widening ground transportation access to the airport from four to six lanes, the arrivals road project for the Port of Seattle provides additional capacity and improves safety.
Air Cargo Road Safety Improvements and Arrivals Road Widening
Updates to air cargo road improved intersection operations, accommodated nonmotorized travel, improved employee parking and transit bus stops, upgraded the cell phone parking lot, and completed illumination signage and landscaping. Otak provided a part-time project manager to oversee this large civil infrastructure project at Sea-Tac Airport.
With goals to improve public safety, reduce maintenance frequency, increase drainage system reliability, restore aquatic and riparian habitat, and improve water quality, the City of Issaquah sought to develop a surface and stormwater master plan (SSWMP). The plan develops a prioritized list of stormwater infrastructure and habitat restoration projects to be implemented within a 20-year timeframe, simultaneously helping the city many its grown while remaining compliant with NPDES permitting. The Otak team worked with the city to develop the plan and subsequent projects that would address the impacts of impaired surface water quality, aquatic and riparian habitat degradation, increased flooding, and aging infrastructure.
In reconnecting Johnson Creek to its historic floodplain, the stream restoration plan provided flood storage for peak flow attenuation, and improved riverine and wetland habitats. Otak led the overall project management, geomorphic assessment, monitoring data interpretation, hydrologic analysis and hydraulic modeling, as well as the comprehensive restoration design.
Enhanced Habitats for Endangered Species
Working with the City of Portland Bureau of Environmental Services (BES), the Cedar Crossing Restoration enhanced native riparian vegetation and tree canopy, creating high-flow refugia for listed Endangered Species Act (ESA) species, particularly several ESA-listed salmonids. Overarching project elements involved demolition of structures, management of contaminated soil as well as a number of complex design, permitting and site preparation considerations. The stream restoration design included in-stream channel structures, bank stabilization, large woody debris structures and the removal of nearly 2,000 feet of a century-old WPA rock wall that lined both banks of the stream.
An affordable housing community takes shape in Lincoln City, Oregon. In designing Wecoma Place, Otak drew inspiration from the site’s surroundings to emulate the enduring nature of the Oregon coast.
Affordable Housing Designed for a Displaced Community
Wecoma Place is comprised of three masses that resemble the large geomorphic shapes along the beach. The various patterns in the siding battens represent the wind-swept grasses found along the coastal landscape. The 44-unit building provides a place to live for residents of Lincoln County displaced by The Echo Mountain Fire in 2020. The units are designed to maximize natural light in the coastal environment and the building is oriented around a courtyard that provides space to recreate and acts as a buffer between the building and Highway 101.
Manage Cookie Consent
To provide the best experience, we use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us to process data such as browsing behavior or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions.
Functional
Always active
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
Preferences
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
Statistics
The technical storage or access that is used exclusively for statistical purposes.The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
Marketing
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.
