The Santa Clara River watershed drains an extensive and biologically rich region at the junction of five of California's 10 identified Bioregions, and contains a particularly strong representation of the biodiversity in the South and Central Coast Bioregions. The river is the last major coastal system in southern California that retains much of its natural hydrology and still provides the ecosystem functions necessary to sustain more than 18 federally listed species. The river system provides critical habitat and landscape linkages between these bioregions, including the Sierra Madre and Santa Felicia mountains to the north and Santa Susana-Simi Hills and Santa Monica Mountains to the south. The river basin also supports some of the most valuable agricultural resources in the world, as well as water resources for surrounding urban populations. Although the SCR contains extensive natural areas, it was identified as a critically endangered river by American Rivers[1] in 2005 because of urban development and other threats in the region. Invasion by giant reed (Arundo donax) is one of the most pressing conservation issues in the watershed.

The RIVRLab is involved in numerous efforts in the Santa Clara River system including:

-Evaluating and implementing biological control for weeds such as giant reed, tumbleweed (Salsola spp.), and Cape ivy (Delairea odorata spp.).
-Ecological restoration
-Genetics and ecophysiology of foundation riparian trees