Highway 17 Wildlife and Regional Trail Crossings Project (Santa Clara County, California)

Julie Andersen, Midpeninsula Regional Open Space District
Meredith Manning, Midpeninsula Regional Open Space District; Tanya Diamond, Pathways for Wildlife; Randy Anderson, TrailPeople; Tony Clevenger. WTI-Montana State University
Topic Area
Terrestrial Wildlife and Ecosystem Interactions with Transportation

A roadkill hotspot has been identified on Highway 17 in Santa Clara County near Lexington Reservoir. Various data point to this location, including wildlife corridor analysis, large carnivore telemetry data, and roadkill data collected from 2000-2018. In this same area, there is a large gap in regional trails due to highway infrastructure and other barriers (roads, water and other infrastructure). This project has significant public support and partial funding.
In 2016, the Midpeninsula Regional Open Space District (Midpen) undertook a feasibility study to determine potential locations for a wildlife and a trail crossing of Highway 17 near Lexington Reservoir. Potential locations for a wildlife crossing were based on: 1) proximity to where animals cross and will continue to attempt to cross, 2) where there is suitable topography, soils, and access to provide appropriately shaped and sized structures, 3) providing habitat connectivity, 4) adequate line of sight, 5) less human exposure, and 6) ability to accommodate special status species. Potential locations for a trail crossing were based on: 1) ability to accommodate full range of potential trail users, 2) direct connections to existing trails, 3) ability to provide a safe and enjoyable trail, 4) ability to provide feasible trail connections, and 5) ability to provide emergency and maintenance access.
A total of eight alternatives at five locations were identified. These include two wildlife only, three combined wildlife and trail crossings, and three trail only alternatives. Ideally two separate structures would be provided (one for wildlife and one for trails), but in the event only one location is feasible, then combined wildlife and trail options are provided. Directional wildlife fencing was identified for each of the structures. All alternatives were submitted to the California Department of Transportation (Caltrans) for review. Construction of new structure(s) will be within the Highway 17 right of way and the completed structure(s) may be incorporated into the state highway system if agreed to by Caltrans. Midpen is working with adjacent landowners, stakeholders, and partner agencies to obtain property rights for wildlife and public trail access across/through future structure(s) as well as initiating maintenance, monitoring, and patrol discussions to develop agreements for future structure(s) and directional fencing. Monitoring and post construction roadkill surveys will determine efficacy of built structure(s) and associated fencing.
In addition to roadkill data and feasible trail connections, the ability to secure property rights, stakeholder negotiations, and available funding will ultimately determine which alternative(s) are able to be constructed. The key is to prepare alternatives that meet the project purpose and goals, so that no matter which alternative(s) are selected they will be beneficial to wildlife and facilitate regional trail connections.

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