Watershed, Summer 2001
The River
Management Plan
Newhall Ranch

FSCR Joins Arundo Task Force

Arundo Donax, also called giant reed, is an invasive weed of major concern in southern California streams, including the Santa Clara River. Arundo is a bamboo-like grass that likes moist soils and temperate climates. It can grow to 25 feet tall and chokes out other native vegetation. It completes with native species such as willows, mulefat and cottonwoods. Native animals, with rare exceptions, do not eat or nest in Arundo. Arundo uses three times more water than native plants and is therefore a significant source of stream dewatering. It clogs up streams and channels, increasing the risk of floods and property damage.

Arundo, a native of the Mediterranean region, was first brought into the United States as an erosion control plant and as livestock feed, and was well established in southern Claifornia by the 1820s.

Eradication of Arundo is difficult and costly and is seldom effective in a single attempt. Continued monitoring of cleared areas and aggressive removal or spray of new sprouts is necessary to have any chance of long-term control. Each time a stream floods, new growth is established from uprooted material washing downstream. Effective control in a watershed such as the Santa Clara, therefore, can best be achieved by concentrating initial removal operations in upper reaches of the river and in tributaries, followed by removal in areas farther downstream.

A new organization dedicated to control of Arundo in Ventura County streams has gotten underway during the past year. Known as the Ventura County Arundo Task Force, this group meets monthly to discuss and coordinate various Arundo control projects in the county. Representatives from federal, state and county agencies plus non-governmental organizations, make up the team, which is under administrative leadership of the Ventura County Resource Conservation District. Friends of the Santa Clara River has joined the team and has signed the Memorandum of Understanding which team members agree will cover their joint activities.

The first effort of Task Force is a Pilot Project along approximately 3500 feet of the Ventura River to investigate various Arundo removal and native revegetation strategies. Project location is in Casitas Springs, upstream of the Edison curve on property owned by the Ventura County Flood Control District. Initial funding for the project has been provided by the California Department of Fish and Game and other funding is being sought. Phase I of the project will begin in the fall of 2001 and will consist of cutting Arundo followed by spraying remaining roots with herbicide to control regrowth. Phase II will begin soon thereafter and will involve planting various types of native vegetation from both containers and cuttings.

FSCR board members Ron Bottorff and Sandy Hedrick spent several hours on June 7 exploring Arundo-infested areas in the upper Santa Clara River. There is a need to identify sites for removal projects in the upper river followed by efforts to secure funding for the projects. Shawna Bautista of the U.S. Forest Service showed us around the region and pointed out areas where the Service has successfully removed Arundo from their property along about a mile of the river in Soledad Canyon. A beautiful riparian woodland has now replaced the Arundo. If you wish to see this yourself, drive up Soledad Canyon Road to the Forest Service Wildlife Viewing area (just west of the Oasis Camp operation). Walk about 50 yards to the west along a trail until you come to a small side stream. The woodland in front of you used to be mostly Arundo. Look for the federally endangered unarmored threespine stickleback fish also along this section of the stream.

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