Farmer-dominated regional councils including Environment Southland have been "bloody useless" in fixing dirty waterways and must up their game or face the axe, Labour Party environment and water spokesman David Parker says.

Parker went on the attack about the quality of water in Southland's rivers, lakes and estuaries during a public meeting in Invercargill on Sunday.

"Regional councils have had full authority since 1991 to deal with this problem and they have been bloody useless, atrocious," Parker said.

Kavinda Herath Dr Liz Craig, the Labour Party candidate.

"Southland can't be proud of what's happened here either."

Cultivation of steep slopes had been illegal and the practice had not been prosecuted, he said.

He targeted Environment Southland councillor Maurice Rodway, who was in the crowd.

"Maurice, you are on that [Environment Southland], I hold you partly responsible for it."

"I believe that's true of every regional councillor."

Increases in land use intensity would no longer be a permitted activity under a Labour government, he said.

Another Environment Southland councillor in the crowd, Robert Guyton, told Parker he had been harsh on Rodway because Rodway spoke the same language as Parker did.

However, Rodway was "overwhelmed" by other members of the Environment Southland council, Guyton said.

Guyton said regional councils wanted to achieve the things Parker spoke about and he asked why it hadn't worked.

Parked said regional councils had been farmer dominated and Dairy NZ and Federated Farmers sometimes defended the indefensible and hunted as a pack.

"Regional councils still feel beholden to the farming lobby and the only way to change is to abolish regional councils or put rules in place."

After the meeting, Parker said a Labour government would make regional councils do their jobs properly rather than axe them.

The public meeting in Invercargill, called 'protecting our lakes and rivers', was hosted by Invercargill's Labour Party candidate Liz Craig.

Craig said Southland had "real issues" with phosphorous, nitrogen and E coli getting into Southland's waterways and some areas not suitable for swimming.

Southland relied on agriculture for a huge proportion of its GDP and most households had meat and dairy products in the fridge.

The region, both urban and rural, had to sort out the issues, she said.

Dipton sheep farmer Peter McDonald said a lot of people were hurt by the environmental conversation going on because it affected them, but it would not go away until things began moving in the right direction.

Southland had a movement of farmers coming together in catchment groups to address the issues, he said.

Eighteen catchment groups had been formed in the region and several more would soon be formed.

"They have been driven by local farmers that want to know the issues in their areas and they want to work towards solutions, so it's a positive thing that's happening," McDonald said.

New Zealand would not be able to promote its agriculture products to high end markets if it had a poor environmental record, he said.

"We get access [to those markets] on top of our clean and green reputation ... but have we been investing in that brand enough? That's what we need to do."

Longwood dairy farmer Ewen Mathieson said nearly all 42 farms in his area had joined the Pourakino catchment group which was working towards establishing values for the Riverton estuary.

Farmers in Southland's 18 catchment groups had a huge awareness of the issues and were doing their level-best to mitigate the impacts, he said.

He was frustrated those groups with differing views couldn't get in the same room for honest discussion and get a plan going forward.

Southland Fish & Game manager Zane Moss put on a slide show revealing how nutrients and sediment had infested the region's waterways and caused slimy algae to grow.

​The decline of the Waituna lagoon had highlighted the issue, which was not about bad farmers, but bad farming practices, Moss said.

Science had revealed some soil types were far more prone to losses of contaminants than others, making farming riskier in some areas than others.

A major issue in declining water quality centred on farmers reliance on fodder crops, especially when grown on slopes, given the runoff of sediments and nutrients when they were grazed in wet winters, he said.

Monday marks the beginning of Environment Southland's Water and Land Plan hearing, with dozens of public submitters to be heard in coming months.

The plan seeks to address water quality issues in Southland.