National Wildlife Federation
Wallis Annenberg Wildlife Crossing
Born out of a decades-long effort to reconnect fragmented habitat, reduce vehicular strikes, and provide safe passage to a larger home range for Puma concolor – the mountain lions of the Santa Monica Mountains – the Wallis Annenberg Wildlife Crossing is a novel green infrastructure and ecological restoration solution that, once completed, will be the largest of its kind in the world. From 2019 to 2024, Living Habitats worked with a project partnership team that included the National Park Service (NPS), National Wildlife Federation, California Department of Transportation (Caltrans), and local and regional conservation groups to develop a holistic design that bridges one of the busiest stretches of freeway in the U.S. to provide critical habitat for a wide range of species – from mule deer to soil microbes – and strategically connect the existing network of natural corridors throughout the mountains.
As the prime consultant leading a robust team of engineers, architects, biologists, and community organizations, Living Habitats performed ecological analysis, designed and prepared bid documents for the project’s first phase of construction, and built out numerous research and infrastructural initiatives to support the project’s long-term goals.
A list of focal faunal species, developed in collaboration with a working group of biologists and ecologists from Caltrans, NPS, University of California – Los Angeles, and other institutions, was a key first step that was instrumental in mapping out the project’s many design decisions. Understanding these unconventional “site users” allowed Living Habitats to tailor all elements of the design – from fencing to drainage – to their needs. Particular attention was paid to abiotic factors such as anthropogenic noise and light pollution, and the team pioneered unique digital modeling processes to understand how effective different design interventions would be in creating a dark and quiet corridor, guiding wildlife toward and over the crossing. As a part of this effort, Living Habitats facilitated the working group’s development of a monitoring and evaluation plan, ensuring that baseline data could be collected, and future research coordinated to measure project outcomes and provide design insights for future crossings.
Pairing the list of focal species with a series of target vegetation communities (coastal sage scrub, chaparral, and oak woodland) led to the establishment of several novel planting and soils strategies. Working closely with NPS and the Santa Monica Mountains Fund, and leveraging staff expertise in horticulture and project management, Living Habitats oversaw the design and installation of a nursery only miles from the project site, which is responsible for growing all the project nursery stock and cultivating site-specific fungal and microbial soil amendments. The planting design for the project represents the three main habitat types and was informed by proposed site conditions, hyper-local availability of seed sources, and relationships of the species with mycorrhizal fungi, wildlife, and each other.
Living Habitats was also responsible for the documentation of Stage 1 construction plans and special provisions. We coordinated closely with Caltrans to fold the project’s novel elements into their rigorous design and documentation standards. Our team also supported Caltrans in construction administration and coordinated stewardship practices with landowner and project partner the Mountains Recreation and Conservation Authority, helping to ensure the project’s future performance and longevity.
Location:
Agoura Hills, California
Date:
2019 – 2024
Team:
NATIONAL WILDLIFE FEDERATION: Client
NATIONAL PARKS SERVICE: Client Partner
CALIFORNIA DEPARTMENT OF TRANSPORTATION: Client Partner
MOUNTAINS RECREATION CONSERVATION AUTHORITY: Client Partner
SANTA MONICA MOUNTAINS CONSERVANCY: Client Partner
WESTERN TRANSPORTATION INSTITUTUE, DR. TONY CLEVENGER: Road Ecology Lead
UNITED STATES GEOLOGICAL SURVEY: Biology
LIMNOTECH: Hydrology
SPIEGEL AIHARA WORKSHOP: Architecture
SYMBIOROOTS: Mycology
OLSSON: Soil Science
WC3: Irrigation
CAL POLY SAN LUIS OBISBO: Acoustic Monitoring
PACHYDERM ACOUSTICS: Acoustic Engineering/Modeling
TRAVIS LONGCORE: Ecology
ALAN SALAZAR: Tribal Consultant
HNTB: Structural Engineering
