In order to help meet the Governor’s border security priorities, the 84th Texas Legislature, in 2015, directed the TSSWCB, through Senate Bill 1734, to develop and implement a program to eradicate carrizo cane along the Rio Grande.
The TSSWCB must develop a program that establishes long-term management of invasive carrizo cane at a landscape scale along the entire Rio Grande, an international border with great ecological and cultural significance. Comprehensively addressing the impacts of arundo on border security are paramount to the program, while also accruing benefits to the ecosystem health of the Rio Grande and water user groups in south Texas.
The process to develop a program will involve affected landowners, municipalities, other state and federal governmental entities, and concerned citizens. The agency is in the "public scoping" stage of soliciting input from the public and affected stakeholders into how this program should be implemented.
The Rio Grande Carrizo Cane Eradication Program should:
- Reduce arundo canopy, density, and biomass
- Improve border access for law enforcement officers
- Improve visibility to allow better detection of illegal activities
- Restore ecological function, degraded riparian habitats, and biodiversity of the Rio Grande
- Improve river function, decrease in-channel sedimentation, and reduce potential for flooding
- Enhance water savings by conserving water lost to evapotranspiration by arundo, even accounting for water use by regrowth of native riparian plants
Due to the diversity of biological, legal, and cultural issues associated with control of carrizo cane along the 1,255-mile Rio Grande international border, the TSSWCB envisions an ecosystem-based approach that integrates the use of biological, chemical, mechanical, and cultural controls, as appropriate, to manage carrizo cane along the Rio Grande. Such an approach should promote the re-establishment of beneficial native plants, and will necessitate a long-term maintenance program to ensure control is successful. Close coordination will be necessary with many local, state, and federal governmental agencies. Participation in the program will be voluntary for landowners.
Improving Border Security and Restoring Ecosystem Function of the Rio Grande Through Invasive Species Control
Large dense stands of non-native carrizo cane (Arundo donax) now occupy the banks and floodplains of the Rio Grande, thwarting law enforcement efforts along the international border, impeding and concealing the detection of criminal activity, restricting law enforcement officers’ access to riverbanks, and impairing the ecological function and biodiversity of the Rio Grande.
Arundo is an exceptionally fast growing plant, able to grow about 4 inches per day and reach a mature height of over 25 feet in about 12 months. These stands of invasive riparian weeds present considerable obstacles for the protection of the international border by law enforcement and agricultural inspectors, by both significantly reducing visibility within enforcement areas and by providing favorable habitat for agriculturally-damaging cattle ticks.
Carrizo cane is considered one of the greatest threats to the health of riparian ecosystems in the southwestern United States, with great negative impact to biodiversity and ecological processes. Arundo does not provide any food sources or nesting habitats for native wildlife. Carrizo cane is linked to sediment accumulation, channel constriction, and increased flooding frequency threatening the riparian ecosystem of the Rio Grande.
Carrizo cane is a noxious brush species that consumes precious water resources to a degree that is detrimental to water conservation. As a result of this weed’s high evapotranspiration capacity, infestations threaten water supplies for agriculture and municipal drinking water uses in south Texas.
Conservation Delivery System
The TSSWCB delivers coordinated natural resource conservation programs to agricultural producers through the State’s 216 SWCDs. SWCDs serve as the State’s primary conservation delivery system through which technical assistance and financial incentives for natural resource conservation programs are channeled to agricultural producers and rural landowners. SWCDs give farmers and ranchers the opportunity to solve conservation challenges locally, instilling in landowners a stewardship ethic and individual responsibility for soil and water conservation.
Many of the TSSWCB’s programs are coordinated through the conservation delivery system of the 216 local SWCDs, including this Rio Grande Carrizo Cane Eradication Program. This Conservation Partnership is one of the most efficient and effective mechanisms for conducting natural resource conservation programs.
TSSWCB is well-experienced in managing programs and projects to control invasive riparian vegetation.
Carrizo Cane Control Demonstration Project in Webb County on the Rio Grande
In 2007, the TSSWCB worked with conservation partners to demonstrate the effectiveness of aerial herbicide application to control carrizo cane for border security purposes. Conducted just outside of Laredo, approximately 120 acres of cane was sprayed on private land along the Rio Grande. The Webb SWCD #337 was critical to the success of this demonstration project.
- $18,000 in State Brush Control Program funding from TSSWCB
- $7,714 in match funding from private landowner, private chemical company, and private aerial applicator company
Funding Needs for Rio Grande Carrizo Cane Control
In order for the TSSWCB to successfully implement the Rio Grande Carrizo Cane Eradication Program, the Texas Legislature estimated a $4.9 million annual budget will be necessary. Funds are needed for:
- local SWCDs to provide on-the-ground technical assistance and conservation planning for private landowners
- direct control and treatment of carrizo cane, to be conducted primarily through private contractors, potentially including:
- mechanical topping to allow for immediate visibility
- aerial and ground application of chemical herbicides
- propagation and distribution of biological control agents
- revegetation of native plants in highly disturbed areas
- conducting scientific investigations to ensure the program is successful, including:
- aerial and remote sensing for detailed mapping of the spatial extent of the cane infestation
- documenting the water conserved from managing arundo
- evaluating treatment impacts on river hydrology, sediment dynamics, water quality, and aquatic health
- two new positions at TSSWCB to provide overall program planning and management, public outreach, and landowner coordination.