Increasing feral pig numbers in the far south-west of Victoria are putting a World Heritage-listed archaeological site in danger.

Key points: Budj Bim's cultural significance could be damaged if wild pigs in the area go unchecked

Budj Bim's cultural significance could be damaged if wild pigs in the area go unchecked The World Heritage-listed site and Victorian farmland are threatened by the feral animals

The World Heritage-listed site and Victorian farmland are threatened by the feral animals State agencies and Budj Bim's traditional owners say they trying to tackle the problem

The Budj Bim Cultural Landscape features an elaborate series of channels and pools created around Lake Condah about 6,600 years ago by the Gunditjmara people to trap and harvest eels and fish.

It is one of the oldest aquaculture sites in the world and was endorsed as a culturally significant site by UNESCO less than four months ago — but feral pigs are placing it under threat.

"There's an ever-increasing problem with (feral pigs)," said Denis Rose, the project manager for Gunditj Mirring Traditional Owners Aboriginal Corporation.

"We hadn't had a pig issue a couple of years ago, or nothing that was noticeable.

"Within the last two or so years, the numbers have exploded."

The remains of stone traps used to capture eels at Budj Bim, in western Victoria in August 2015. ( ABC News: Bridget Brennan )

Mr Rose said the UNESCO assessors asked questions about feral pigs during a site visit last year.

"It has the potential to really put the Budj Bim world heritage listing at some sort of risk," he said.

Gunditjmara elder Denis Rose in front of what's left of a small stone house built by the Gunditjmara people. ( ABC News: Steph Juleff )

"Those aquaculture systems — the fish traps out on the lava flow — are potentially under immense threat from feral pigs.

"They scratch around within the wetlands and they can do some tremendous damage just to the wetland itself.

"But if they are in fact digging and uprooting our fish trap system then the actual [cultural] value … of Budj Bim will diminish."

'Matter of time'

Information provided by the State Government states that since 2015 its agencies have noticed groups of pigs in areas around Heywood, Portland, Dartmoor and Casterton.

Mr Rose said Gunditj Mirring Traditional Owners Aboriginal Corporation and the Victorian environment department have been working on "a fairly intensive trapping program" on Indigenous-owned land, Crown Land and private farms.

Martin Knowles, who runs a farm at nearby Tyrendarra, said the feral pig problem is the talk of the district.

"Every farmer you talk to is either being impacted by it or they're just waiting for the evidence to crop up on their place," Mr Knowles said.

"They're pretty close — they're only a couple of hundred metres from our property where I've seen evidence they've been there, digging up the ground.

"You see the mess they make on the side of the roads - that's the last thing we need.

Feral pigs can dig up large sections of ground in a short period of time in search of food. ( Supplied: Basalt to Bay Landcare Network )

"They make a hell of a mess.

"It's only a matter of time — they've just got to go through a big bush block and they're on our place.

"I'm just waiting now — it won't be too long and they'll be running around.

"A few of my mates, sheep and beef farmers, [have had feral pigs] on their property and done a fair bit of damage."

Mr Knowles said the pigs have only appeared in the region in the past couple of years.

Damage potentially 'catastrophic'

Basalt To Bay Landcare Network facilitator Lisette Mill likened the damage to unwanted ploughing.

Ms Mill said two feral pigs dug up a 30-metre wide, kilometre-long stretch of fire break between bushland and farm paddocks.

Feral pigs captured by a motion-sensor camera in south-west Victoria. ( Supplied: Basalt to Bay Landcare Network )

"They dig down in places to a depth of 30 centimetres and, in many parts of our region, that's the entire topsoil profile," she said.

"In many properties that's your most valuable asset."

She said that if feral pigs are left unchecked in the Lake Condah and Budj Bim area, the damage to the World Heritage site could be catastrophic.

"Feral pigs need access to water, they will congregate where the water is, which happens to be sensitive wetlands," Ms Mill said.

The area around Lake Condah, in western Victoria, known as Budj Bim contains evidence of one of the world's oldest aquaculture systems. ( ABC News: Bridget Brennan )

"Given that a lot of the really precious parts of Lake Condah are in the waterway or in the wetlands, that's an immediate damage risk to some of those sensitive assets.

"[If they] get dug up and destroyed by pigs, that would just be heartbreaking, wouldn't it?"

Parks Victoria, Agriculture Victoria, and the Department of Environment, Land, Water and Planning (DELWP) issued a joint statement on the matter.

"We're working across several agencies and with local landowners and community groups to tackle feral pig management together," the statement said.

The authorities urged anyone who spots feral pigs in bushland or state forest to contact Parks Victoria or DELWP, and for farmers to consult Agriculture Victoria.