An outbreak of Cabomba, a highly invasive aquatic weed, has been largely controlled in the Broken River in and upstream of Lake Benalla after almost 6 years of effort.
Goulburn Broken Catchment Management Authority (CMA) Project Manager Tim Barlow said Cabomba was a serious threat to irrigators and other water users given its capacity to clog pumps and filters.
“In addition, it seriously compromises the aesthetic and recreational value of waterways and wetlands, and smothers the native aquatic vegetation that provides valuable habitat for fish and waterbugs,” he said.
“After almost 6 years of effort Cabomba is considered eliminated from Holland’s Creek, and hasn’t been seen in Lake Benalla for more than 4 years, which is fantastic.
“This has been achieved by the strategic drawdown of water levels to dry or remove weed patches, without the use of special aquatic herbicides.
“It’s very exciting to see the system recovering – we recently discovered patches of native Ribbon Weed, which is considered an indicator of good habitat quality, re-establishing in the Hollands Creek near Jaycee Island.”
The remaining population around the Casey’s Weir area is proving more difficult to control, and will be the focus of work this year.
“We are keen to eliminate the weed to protect irrigation equipment, and to protect the ecological values of significant wetlands such as the nearby Winton Wetlands, and the wetlands within Barmah National Park downstream on the Broken Creek,” Mr Barlow said.
“The Victorian Department of Economic Development, Jobs, Transport and Resources, Benalla City Council, Goulburn-Murray Water and local users are involved in the planning and implementation of this project.”
Popular as an aquarium plant, Cabomba has fan-shaped leaves that sit mostly underwater, and a white flower floating on the surface.
To prevent further infestations, it is essential that aquarium plants be composted and not disposed of in or near waterways.
“It is important that we act quickly to control the weed,” Mr Barlow said. “Any observations of the plant should be reported to the Goulburn Broken CMA immediately.”
The project is funded by the Australian Government.
For more information visit www.gbcma.vic.gov.au or phone 5822 7700.