2020 Annual WASLA Conference

Integrating Ecosystem Restoration into Sound Transit's East Link Extension Light Rail Project


The development of Sound Transit's light rail network throughout metropolitan Seattle has faced many challenges, including the avoidance of environmentally sensitive areas. The East Link Extension project, which will service Bellevue and a small portion of Redmond, will have unavoidable impacts to wetlands, streams, and their associated buffers. Nearby mitigation sites were very limited in this highly urbanized location, but a significant amount of the compensatory mitigation was handled within two Bellevue sites: the West Tributary to Kelsey Creek site and the Sweyolocken site. Both sites encountered engineering and permitting challenges, but they have both been successfully installed. The success of ecological and engineering functions will be closely monitored in the short- and long-term in an effort to assist other future projects of similar nature.

Speaker Bios:

Jason Long, Senior Landscape Architect - HNTB Corporation

Jason is a Professional Landscape Architect with 26 years of experience. He has managed and developed a variety of plans and reports for municipalities throughout western Washington and Arizona. Jason's main focus has always been to bridge the gap between natural and built systems, and he has successfully incorporated sustainable design techniques whenever the opportunity arises. His experience in site planning, landscape architecture, wetland and stream restoration and mitigation, low impact development design, erosion and sediment control, and environmental planning and permitting have proven to be an asset in sustainable design efforts. Jason's knowledge of local and regional regulations and procedures, combined with his understanding of ecological demands, has been regularly integrated into projects involving site planning, landscape design, and LID planning and implementation.

Marti Louther, Environmental Compliance Manager - Sound Transit

Marti is a wetland biologist with 25 years' experience working in wetland identification, permitting and restoration in the Pacific Northwest. She currently works for Sound Transit in their Environmental Compliance Division, which focuses on ensuring that all projects are developed, designed, and constructed to meet federal, state and local critical areas regulations. Marti works closely with a variety of technical experts including wetland scientists, landscape architects, fisheries biologists, and hydrogeologists to guide and develop habitat restoration projects. These projects off-set impacts from light rail, train, and bus expansions.

Minsoo Doo, Landscape Archtiect - HNTB Corporation

Minsoo is a landscape architect with experience in landscape design, wetland and stream restoration, and environmental planning. He works with transportation engineers, natural resource scientists, and environmental planners to address some of the most challenging and complex transportation and other municipal projects in the region. He has also assisted public and private clients in all phases of planning, design, and construction projects located in Washington, New York, and Virginia. Additional experience includes field sampling, spatial analysis using geographical information system (GIS), and preparing graphics and visual simulations. Minsoo is also experienced in the LEED rating system, sustainable design, and low impact development design (LID) and implementation.

Learning Objectives:

  • Measure ecological functions within both sites to meet permitting requirements and to share results with other projects of similar nature.
  • Evaluate hydrologic and hydraulic functions over time and the relationship with ecological functions.
  • Analyze native vegetation growth and determine why certain species are succeeding or not succeeding.
  • Study all ecological and engineering functions as urban structures are developed adjacent to and near the West Tributary to Kelsey Creek site.