Mitigation for Arroyo Toad Habitat and Other Listed Species at Vessels Mitigation Site, San Diego County

Rush Abrams, California Dept of Transportation
Michael Galloway, California Dept of Transportation
Topic Area
Mitigation for Transportation Projects

The California Department of Transportation (Caltrans) widened and realigned SR-76 from South Mission Road to Interstate 15. The Vessels site provided biological mitigation for impacts resulting from the project.
Mitigation at the 162-acre site included 87.7 acres riparian re-establishment, 22.9 acres for riparian rehabilitation, and 48 acres for upland restoration. To re-establish habitat, suitable for the federally endangered arroyo toad (Anaxyrus californicus) and other federally listed species, approximately 671,500 cubic yards of sand and soil on the site were excavated from an area of approximately 63 acres. The site was planted and seeded with appropriate native species suitable for arroyo toad habitat. The goal is an open scrub vegetation, with a mix of riparian and upland shrubs and a significant cover of annual and perennial forbs and grasses.
After one year of monitoring, absolute vegetation cover averaged 72 percent, which included
36 percent for trees; 23 percent for shrubs, and 32 percent herb cover. No arroyo toads were observed during protocol surveys; however, the site already has excellent potential for providing breeding habitat for arroyo toad.

Abstract Keywords
Biological mitigation
transportation projects
arroyo toad