Learn how the Riverside County Regional Park and Open-Space District (RivCoParks) protects natural habitat in the Santa Ana River Watershed. Featuring a discussion on the invasive Giant Reed, also known as Arundo Donax. Natural Resources Manager Joe Sherrock talks about the local watershed, the need to eradicate this non-native plant species and the work being done to restore the native habitat.
The Santa Ana River system is California’s largest watershed south of the Sierra mountains. At almost 100 miles long, it spans parts of San Bernardino, Riverside and Orange counties on its way to the Pacific Ocean.
The river is not only an important water source, but the watershed itself also provides habitat to thousands of sensitive native plant and animal species such as the birds like the least Bell’s vireo and yellow warbler, and fish like the Santa Ana Sucker and Arroyo chubb. Unfortunately, these species are being threatened by the introduction of invasive plant and animal species that pose a threat to their sensitive habitat.
Invasive plant and animal species have caused problems in the Santa Ana watershed for many years. One of the most troublesome invasive species is the Giant Reed – known by its scientific name Arundo donax or just Arundo. The giant reed is similar to a tall grass or bamboo, but grows very rapidly. It produces thick stands over 30 feet tall, and can quickly take over areas of native vegetation. It can also block streambeds, and generally degrades the habitat of the native species that call the Santa Ana River their home. This plant species came from the Mediterranean is not native to our region. Arundo thrives along the river, and it easily reproduces from plant fragments and roots that wash down the waterways. On top of this, these large, dry stands of Arundo increase the risk of wildfire as well.
The Riverside County Regional Park and Open-Space District (RivCoParks) Natural Resources Division is tasked with the eradication of Arundo and restoration of degraded areas for the benefit of native species. We do this using a number of methods including removal with tractors, hand tools, and carefully conducted herbicide applications. Once removed, we then take efforts to plant the area with native riparian plants such as willows, cottonwood, and mulefat. The dead Arundo cane stalks are used as a natural protective covering for riparian seedlings. Then we put these native plants on a drip irrigation system to get them established on the landscape with the goal of restoring the area as functional habitat for native animal species.
After two decades of work, over a thousand acres of Arundo have been removed from the Santa Ana River watershed. However, these lands still require stewardship and long-term management in order to ensure that our watershed continues to function as an important part of the landscape. The Park District works with a wide range of state and federal conservation agencies as well as other organizations such as the Santa Ana Watershed Association, and the Santa Ana Watershed Protection Authority to ensure the continued health of our watershed.
Arundo eradication, or abatement, is just one of the conservation and preservation projects of the Riverside County Regional Park and Open-Space District. We encourage everyone to educate themselves about our natural environment and get involved in conservation and preservation. If you questions about the Arundo abatement project, or would like to volunteer or support the Park District’s projects, feel free to contact Joe Sherrock at JSherrock@rivco.org or call (951) 218-4509.