Nature-based Resilience for Coastal Highways

Tina Hodges, FHWA, and Mike Ruth, FHWA
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  • Mike Ruth, Federal Highway Administration
  • Tina Hodges, Federal Highway Administration
  • Bret Webb, University of South Alabama
  • Stefanie Hom, Metropolitan Transportation Commission
  • Kristin Tremain, AECOM
  • Jeffrey K. King, US Army Corps of Engineers
  • Philip Wurst, Oregon DOT


Transportation agencies must protect expensive public infrastructure from coastal flooding, especially as rising sea levels, higher storm surges, urbanization, and ecosystem stresses add complexity to already dynamic coastal systems and communities.  This session will explore how transportation agencies can use nature-based solutions to protect coastal highways from the damage and disruption of flooding and erosion under current and future conditions, while providing habitat and recreation benefits.

FHWA will be releasing an implementation guide in summer 2019 that will provide transportation agencies with information on how to use nature-based solutions, such as restoration of marshes, reefs, and dunes, to protect coastal highways from flooding.  The implementation guide builds on an earlier white paper, series of peer exchanges, and five pilot projects with state transportation agencies.

The 21 mile SR-37 corridor follows the shore of San Pablo Bay, connecting the east and west portions of the northern San Francisco Bay Area.  This congested highway traverses an ecologically sensitive wetlands area and is vulnerable to coastal flooding. SR-37 was closed for a month in 2017 due to flooding from heavy storms, and based on current sea level rise projects, the highway is expected to be permanently inundated by 2050.  Working with numerous partners, Caltrans and MTC developed a strategy that integrates transportation, ecosystem, and sea level rise adaptation into one design.

US Army Corps of Engineers research and pilot projects demonstrate the ability of nature-based solutions to provide flood protection as well as environmental benefits. USACE is also leading an effort to develop international guidelines for natural and nature-based features.

Oregon DOT developed conceptual designs for nature-based flood protection for three locations along coastal highway US 101 vulnerable to storms and coastal bluff erosion. These designs included cobble beaches, artificial dunes, sand tubes, mechanically stabilized earth, rip rap, and planted terraces. Oregon DOT analyzed the coastal protection potential of these designs using wave runup analysis. Oregon DOT also engaged land use and permitting agencies on design options.

Mike Ruth is an Ecologist at the Federal Highway Administration.  Current projects include Eco-Logical, NEPA and permitting streamlining, nature-based resilience, and tidal restrictions.  He worked previously for the US Army Corps of Engineers.

Tina Hodges is an Environmental Protection Specialist at the Federal Highway Administration, specializing in sustainability and resilience.  She leads FHWA’s Nature-based Resilience for Coastal Highways project.  She holds a Masters in Public Policy from the University of Maryland.

Bret Webb is a Professor of Coastal Engineering at the University of South Alabama.  His research focuses on coastal resilience and nature-based solutions.  He is co-editor of an upcoming book on living shorelines.  He is a registered professional engineer and a Board Certified Coastal Engineer.

Stefanie Hom is a principal transportation planner at the San Francisco Bay Area's Metropolitan Transportation Commission. Projects include sea level rise adaptation strategies for Alameda County, SR37, and Dumbarton Bridge corridor.  She holds a Master of City and Regional Planning from Rutgers.

Kristin Tremain is a Project Manager, Senior Biologist, and Climate Ecologist at AECOM with over 11 years of expertise in transportation and climate resilience. Her work integrates natural resources resiliency into the planning and design of restoration, transportation and infrastructure projects. 

Jeffrey K. King, PhD, PE serves as Deputy National Lead for the Engineering With Nature Initiative for the US Army Corps of Engineers.  In addition to leading and managing a broad array of EWN activities and collaborative efforts, Jeff is also advancing R&D projects within the EWN portfolio.

Philip Wurst is a Senior Geotechnical Engineer at the Oregon Department of Transportation.  He served as a key member of the pilot project team analyzing nature-based strategies to protect the Oregon coastal highway from bluff erosion and sea level rise.