Water weed nearly licked

An outbreak of Cabomba, a highly invasive aquatic weed, has been largely controlled in the Broken River in and upstream of Lake Benalla.

Cabomba plant.  Photo courtesy of Andrew Petrochevski

Goulburn Broken Catchment Management Authority (CMA) Acting River Health 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 five years of effort Cabomba is considered eliminated from Holland’s Creek, and hasn’t been seen in Lake Benalla for three years.  This has been achieved by the strategic drawdown of water levels to dry or remove weed patches, without the use of special aquatic herbicides.”

The remaining population around the Casey’s Weir area is proving more difficult to control, and will be the focus of work over the next couple of years. 

“We are keen to eliminate the weed both to protect irrigators’ interests, and the ecological values of significant wetlands such as the nearby Winton Wetlands, and the Barmah National Park downstream on the Broken Creek,” Mr Barlow said. 

“The Department of Environment and Primary Industries, Benalla City Council, Goulburn Murray Water and local users will be involved in the planning and implementation of this work.”

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 not be disposed of 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.