Designing the San Jose to Merced Project Section of California's High-Speed Rail System to Support Wildlife Movement

Stephanie Parsons, California High-Speed Rail
Date From
Date To
Big Sur


  • Stephanie Parsons, California High-Speed Rail
  • John Hunter, California High-Speed Rail
  • Rebecca Sloan, ICF
  • Jake Smith, Santa Clara Valley Open Space Authority
  • Rosanna McGuire, HNTB


The San Jose to Merced project section of the California High-Speed Rail Project passes through urban, agricultural, and natural landscapes in the Santa Clara Valley, Inner Coast Range, and San Joaquin Valley. In these landscapes, the alignment crosses multiple regionally significant corridors for wildlife movement. Some, such as Coyote Valley in Santa Clara County, are already imperiled by infrastructure and development. These corridors are used by a diverse assemblage of animals. Because the HSR project will be bordered by an 8-foot-high security fence for much of its length, it could block wildlife movement in these corridors and elsewhere. However, the California Streets and Highway Code and California Environmental Quality Act mandate that the HSR system mitigate its effects on wildlife movement to the extent feasible.

Therefore, we designed more than 80 wildlife crossings for the project, and modified other design features, to substantially reduce effects on wildlife movement. We did this through an iterative process involving planners, biologists, GIS analysts, and engineers, with participants representing the California High-Speed Rail Authority, local government agencies, and non-governmental organizations. It allowed for project modifications to reduce impacts, resolved conflicts among design features, and addressed stakeholder concerns and applied their local knowledge. This process was informed by earlier HSR experience in planning and designing for wildlife movement in the Central Valley and Southern California.  

Along the project's alignment, we modeled permeability to movement of focal species selected to represent different movement guilds under existing and post-project conditions. For locations with reduced permeability, we evaluated the effects and worked with local stakeholders and experts to inform design-related solutions. Solutions included dedicated wildlife undercrossings, fencing and culvert modifications, and embankment conversion to viaduct. 

Our panel's presentations will provide an overview of the project, its context, and approach to maintaining wildlife movement; a description of the permeability modeling used to evaluate project effects; stakeholder participation in and contributions to the design process; and the engineering challenges posed by wildlife crossings and how these were solved. 

Our interactive discussion will focus on sharing insights on how to effectively develop transportation projects to support continued movement of wildlife.

Stephanie Parsons, CHST Program Permit, Mitigation, and Compliance Lead, is responsible for developing and implementing natural resource permits, mitigation strategies, and compliance approaches for the project. She is a biologist with over 20 years of professional experience as a leader in strategic and collaborative permitting and compliance implementation.

John Hunter serves as California High-Speed Rail's task lead for biological resource planning and permitting for the San Jose to Merced Project Section. He is an ecologist with more than 30 years of professional experience with ecological research, conservation planning, and the design, assessment, and permitting of water, energy, and transportation projects. He received his doctorate in plant biology from the University of California Davis, has taught at State University of New York Brockport, edited the peer-reviewed journal Madroño, and currently serves on the board of directors of the California Native Plant Society.

Rebecca Sloan is the lead author of the San Jose to Merced Project Section Wildlife Corridor Assessment Report. She has more than 15 years of experience conducting ecological research and technical analyses to inform regulatory compliance and mitigation planning for water, energy, transportation and resource development projects. She holds a Bachelor's of Science in Marine Science and a Master's of Science in Environmental Studies and has severed as the Science Advisor for the Stevens & Permanente Creeks Watershed Council and on the board of the Central Coast Chapter of the Conservation Society.

Jake Smith works on Real Property and Conservation Initiatives at the Santa Clara Valley Open Space Authority, where he helped to coordinate the Authority's engagement with the California High-Speed Rail project. He has over 7 years' experience supporting multi-partner strategic planning and land conservation projects and has helped develop the Santa Clara Valley Greenprint, The Coyote Valley Landscape Linkage, The Santa Clara Valley Agricultural Plan, and the Coyote Valley Water Resources Investment Strategy. He Jake holds a B.S. in Environmental Management and Protection and a M.S. in Coastal and Watershed Science & Policy.

Rosanna McGuire is an environmental planner at HNTB in Oakland, California. For the past few years, she has helped coordinate environmental analysis and engineering design for San Francisco to San Jose and San Jose to Merced HSR project sections, including managing design of wildlife crossings. She has 10 years of experience in environmental planning, primarily in developing and reviewing environmental impact assessments and monitoring environmental compliance on construction projects. Her undergraduate degree in ecology, masters in environmental studies, and early career work as a wildlife biologist provided the foundation for understanding project impacts on all environmental resource areas.