Bund wall to support noxious weed eradication

Motorists on the Cox Peninsula Road are being asked to take extra care as they pass over the Darwin River Bridge on Cox Peninsula Road, as the construction of a bund wall on the downstream side of the river has commenced.

The bund wall forms part of an intensified eradication program of cabomba (Cabomba caroliniana) an aggressive and invasive aquatic weed, recognised as one of the 32 worst weed species in Australia and listed as a Weed of National Significance.

The bund wall has been constructed to prevent the potential flow of herbicide into Darwin Harbour before it naturally breaks down, and allows for scientific monitoring of cabomba, the environment and water quality.

Cabomba Eradication Program Manager Mr Chris Collins said that the bund wall was being constructed ahead of an intensive herbicide treatment of a one kilometre section of the Darwin River where the weed is growing.

“We have fought against cabomba for 12 years and have successfully removed it from all but this one section of Darwin River; with intensified monitoring and herbicide treatment before the wet season we hope to finally eradicate cabomba from the Northern Territory,” he said.

“If allowed to spread, the impact of cabomba could be devastating to the Territory’s wetlands. Just one small piece of plant could infest our waterways, causing incredible damage to water quality as well as our fishing and tourism industry. It’s just not worth the risk.”

The Cabomba Eradication Program includes a quarantine zone of the Darwin River between Cox Peninsula Road and Leonino Road crossings, until November 2017.

The quarantine order prohibits the movement of people and any object, including boats, vehicles and fishing equipment, into or out of this section of river and within the five metres of land adjacent to the water’s edge.

Non-compliance with the order could result in an on-the-spot fine of $261 and penalties of up to $100,000 for individuals and $500,000 for corporations.

“Over the coming weeks we will treat the impacted section of the river with an aquatic herbicide which has proven successful in the removal of cabomba in other Australian jurisdictions. The bund wall provides additional protection on the boundary of the quarantine zone to downstream salt water systems including Darwin Harbour,” Mr Collins said.

The bund wall will be constructed by ABT (NT) and consist of approximately 1900m3 of clean fill stabilised by geotextile. The wall will be approximately 5 metres high. Major works will take place during this week and are expected to be completed by Monday 10 October. Traffic management systems will be in place.

“We would like to thank the community in advance, particularly those frequently using Cox Peninsula Road, for their patience during the works. We cannot stress how important it is that we remove this noxious weed from our waterways and trust that everyone abides by the quarantine zone.

“We have worked tirelessly to eradicate this weed in the NT and this is the last known location of cabomba. We urge Territorians to stay out of the Quarantine Zone; it is not worth the risk to our waterways, but it is also not worth the risk of a fine.”

For more information on the Cabomba Eradication Program go to nt.gov.au/weeds