Dairy farmers in Canterbury could be pushed to the brink of bankruptcy by new rules designed to limit pollution from farm animals, a local farmer says.

Photo: RNZ / Alexander Robertson

Canterbury Regional Council's Plan Change 5 to the Land and Water Regional Plan involves limits being placed on, for example, how much urine is deposited on paddocks by dairy cows.

The intention is to reduce the leaching of harmful nitrates into surrounding waterways.

Mid-Canterbury dairy farmer Willy Leferink said in some cases this would force farmers to reduce their herd size, which could send them bankrupt.

"Some will get very close, yes," Mr Leferink said.

"At the moment there's not a lot of space, most farmers are just coming back from a disaster, a lot of farmers have incurred a lot of debt in order to keep their businesses afloat.

"The banks have been very supportive there, but if we have to have a lot of money taken from our bottom line, then we have no means of paying that back to the banks."

Mr Leferink, who has interests in several farms managing a total 3500 cows, said Plan Change 5 would prevent farmers in the region from increasing their herd sizes any further.

He predicted the region had now reached 'peak cow'.

"Every cow drops so much phosphate and nitrogen on the land so they don't want more of it, so the biggest thing to cut back is cutting cow numbers. If you don't have a lot of leeway and a big mortgage to pay it's going to be hard work to work your way through that."

Federated Farmers regional president Michael Salvesen, who also farms in Mid-Canterbury, said those in vulnerable areas, including land with more porous soil or where there were already a lot of cows, might need to apply for a resource consent to farm.

That would again hit their bottom line, he said.

"The minimum cost of a consent was $1700 and that's assuming it's fairly straightforward. If it's not straightforward the cost increases and I've heard of people spending up to $30,000 so far."

Farmers might be forced to bring their cows indoors to get them off the land and better control the amount of nitrate-producing urine getting into waterways, he said.

Regional Council chairperson David Bedford admitted some farmers would need to reduce their herd sizes in order to comply with the new rules.

They would have two years to bring their farms up to scratch before any enforcement action was taken, he said.

"Now, I can't comment on how well positioned each farmer is to deal with that change, but these requirements are quite tough, they are actually insisting now that in certain circumstances farming practices will have to change quite significantly."

Plan Change 5 was open to appeals, which under special government legislation would be limited to the High Court.

It was hoped the new rules would come in to force from the beginning of next year.