Project Narrative

Arundo (commonly referred to as giant reed) has significant negative impacts on water availability, water quality (i.e. sediment loads, temperature, pathogens, nutrient loading, flow modification), habitat, fires, and infrastructure. Arundo transpires water at a rate that is 5x higher than native vegetation. Analysis from Cal-IPC’s Arundo donax Distribution and Impact Report (March 2011) demonstrates that for every one-acre of Arundo removed, 20 AFY of water would be available downstream for capture/recharge and in-stream flows. This clonal plant from eastern Asia grows into dense stands via horizontal underground stems (rhizomes) and can reach heights up to 30 feet. Arundo becomes so dominant in riparian systems that it alters hydrological and geomorphic processes. Arundo stands can also significantly increase fuel loads and fire frequency potential (acting as both an ignition source and fire conveyance across riparian areas). The plant out-competes all native vegetation, impacting environmental resources and habitat beneficial uses. It has almost no biological value–no insects or wildlife feed on it, few organisms inhabit stands (i.e. poor nesting structure for birds), and stands impede movement in and through riparian zones. The proposed project will remove Arundo from private land in five tributary canyons located along north side of San Fernando Valley: Box Canyon, Devil Canyon, Pacoima Canyon, Little Tujunga Canyon, and Big Tujunga Canyon. All five of these canyons eventually drain to the Los Angeles River. The total project area affected is approximately 300 acres, with approximately 5 miles of stream corridor. Primary vegetation communities are riparian woodlands dominated by native white alder, sycamore, cottonwood, and willow species.