Crocodiles have long ruled the waterways of the Top End, but now there’s a new predator on the scene, and its teeth are just as sharp.

Loading...

“It’s the sort of thing you wouldn’t want to get caught in, just like the crocodiles in Fogg Dam – you wouldn’t want to get caught in them either” - Jeremy Hemphill, Friends of Fogg Dam ( Marty McCarthy )

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Listen Duration: 6 minutes 9 seconds 6 m Jeremy Hemphill from Friends of Fogg Dam explains the floating weed machine ( Marty McCarthy ) Download 2.8 MB

At Fogg Dam, an hour east of Darwin, a new machine, operated by prisoners, is cruising the flood plains and ripping up everything in its path.

The floating harvester is part of a plan to control invasive weeds at Fogg Dam Conservation Reserve, and to rehabilitate the struggling wetland.

"I don't think you want to get in the way of it, no," said Jeremy Hemphill, from Friends of Fogg Dam.

“The cutters are actually like a sickle bar harvester that people used to use for cutting hay.

“It’s the sort of thing you wouldn’t want to get caught in, just like the crocodiles in Fogg Dam – you wouldn’t want to get caught in them either.”

Mr Hemphill helped bring the machine to the man-made dam, with the support of the Northern Territory Department of Parks and Wildlife.

Fogg Dam is a remnant of the Northern Territory's failed Humpty Doo Rice Project in the 1960s.

The site has since become a 300-hectare open waterway and wetland that is popular with bird watchers, but in recent decades the dam has become overrun with weeds.

Mr Hemphill says the floating weed harvester will change all that.

"It's pretty impressive. All the visitors to Fogg Dam were pretty impressed by it and stood by watching it work," he said.

"The results have been impressive as well. There's now quite a lot of open water."

"It's more [for removing] the eleocharis sphacelata weed, and there's also a lot of floating grass mats and melaleucas.

"Fogg dam is registered as an important birding area, and it rates in the top 10 birding sites by Australian Geographic and BirdLife Australia.

"A lot of people want to see open water so that the migratory birds that used to come here 20 years ago come back.

"Ducks and geese are now visible on the dam, which they couldn’t do before."

The harvester will have to operate for a full day, five days per week for a year if it is to clear all the weeds from Fogg Dam, but Mr Hemphill says the work won’t stop there.

"It's like the Sydney Harbour Bridge. Once you finish you have to start all over again," he said.

The weed harvester is operated by two low-risk prisoners.

"Charles Darwin University is training them so they have skills when they depart the prison system, so it's a great community program," Mr Hemphill said.

"The guys operating it do say that there's sometimes a crocodile that swims fairly closely to the thing, waiting for them to fall out."