Delta Region Areawide Aquatic Weed Project
Delta Region Areawide Aquatic Weed Project
Delta Region Areawide Aquatic Weed Project
University of California
Delta Region Areawide Aquatic Weed Project

Mapping and prioritization of sites for biological and integrated control of Arundo in the Sacramento-San Joaquin Delta


Dr. Patrick Moran, Research Entomologist, USDA-ARS Exotic and Invasive Weeds Research Unit.

Aaron Haiman, Environmental Scientist, Sacramento-San Joaquin Delta Conservancy,

Thomas Jabusch, Senior Environmental Scientist, Sacramento-San Joaquin Delta Conservancy,



Mark Newhouser, Sonoma Ecology Center

Miles Daprato, Solano RCD



  • Select sites for biological control of Arundo through mapping and prioritization of Arundo infestations. Make landowners contacts leading to site access.
  • Conduct and assess non-biological control of Arundo and coordinate with biological control efforts.



Arundo (Arundo donax), a giant grass up to 25 ft tall, grows along the edges of sloughs and canals in the Sacramento-San Joaquin Delta, and is also abundant in the Sacramento and San Joaquin River watersheds. Arundo restricts shoreline access, consumes/wastes water, obstructs flood control channels, creates fire hazards along sloughs and rivers, and displaces native plants.

The Delta Conservancy, as a primary state agency for Delta ecosystem restoration, identified the need to address Arundo and restore the areas with native vegetation. The Delta Conservancy is working in collaboration with state and federal agencies, non-profit organizations, and private landowners to plan and implement an Arundo Control and Restoration Project.

For this DRAAWP project, biological control of Arundo will be implemented and monitored by USDA-ARS, a DRAAWP project collaborator. SSJDC (with collaborators Sonoma Ecology Center and Solano Resource Conservation District) is mapping and prioritizing sites, coordinating access with landowners, and coordinating different treatment efforts.



Collaborators at Sonoma Ecology Center mapped Arundo populations in the Delta using both satellite images and ground-level surveys. Arundo infestations were digitized from 2011-2012 high resolution aerial imagery within the boundary of the Legal Delta. Field verification was conducted by vehicle or boat with approximately 50 percent of mapped points validated by site visits. They have also prioritized sites using a restoration prioritization model with habitat suitability data for multiple species, and input from a Biologist Review Group.

The SSJDC, in collaboration with Solano Resource Conservation District, is identifying potential sites for integrated Arundo control and coordinating with landowners. SSJDC is facilitating data sharing of treatment methodologies and effectiveness.


Products / Outcomes

  • Map of Arundo populations in the Delta [completed]
  • Prioritization of Arundo sites within the legal Delta for eradication according to a developed multi-species conservation value model [completed]
  • Identification of sites where biological and other control methods can be used to treat Arundo and subsequent restoration could be conducted [ongoing]
  • Treatment of Arundo with chemical/mechanical methods and monitoring of effectiveness [ongoing]

Funding provided by:
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