'Farming doesn't pollute rivers' - Federated Farmers rep

A Federated Farmers spokesperson has claimed farming has no effect at all on water quality in New Zealand.

The Green Party has announced plans to put a halt on new dairy farms and introduce a nitrate pollution levy in order to reduce the widely agreed upon problem of waterway pollution.

However, Federated Farmers Wairapapa Dairy chair Chris Engel said there is no problem to fix.

"I don't know where [rivers] are dirty. I can take you down to our river; we swim in it," he told Newshub during an interview on his own dairy farm.

"What is it that we're doing that's not sustainable? I would call this sustainable farming. There are the cows. That's what the customer wants to see. They want to see the cows outside. They're sitting down. They're happy."

When asked to quantify the water pollution created by dairy farms, Mr Engel responded, "I don't see where they are."

Asked directly if farmers are contributing to polluted waterways in New Zealand, he replied, "No."

Mr Engel conceded that "maybe" there is some water pollution in New Zealand, but that "generally [that is] associated with urban issues".

"The cows are eating grass, which is grown naturally, and then it grows again next month. It's the most sustainable form of business I think you could ever have."

Freshwater ecologist Mike Joy of Massey University says the science is clear - the biggest impact on the waterways of New Zealand has been dairy intensification.

He says it makes no sense to start cleaning up rivers if you aren't stopping what's polluting them first.

"At the moment it's like we've got a pot of milk boiling over on the stove and what people are saying is 'let's just buy more sponges to clean it up' when the obvious thing to do is turn the stove down,"says Dr Joy.

"There's no doubt - and I can quote you many scientific papers that prove this - the biggest impact on our rivers over the past 20 years is from dairy intensification."

According to the Ministry for the Environment, more than 60 percent of monitored rivers in New Zealand are unsafe to swim in, a problem largely blamed on sediment, bacteria and nutrients from the agriculture industry.