River and lake pollution has been ranked as one of the country's top concerns in a public opinion poll.

Photo: RNZ / Jessie Chiang

The Colmar Brunton poll surveyed a thousand New Zealanders, 75 percent of which said they were extremely or very concerned about the pollution of waterways.

The cost of living was the only issue which trumped river and lake pollution, worrying 77 percent of those surveyed.

Fish and Game chief executive Martin Taylor said over the past year alone concerns had grown and would continue to stay relevant to the New Zealand public.

"When you can't swim in Lake Taupō because of the toxic alert it remains in front of the public eye.

"When you have to cancel an international sporting event in Taupō because of water quality, when Lake Ellesmere is so toxic that it's going to kill your pet - it will remain in the public eye," he said.

Mr Taylor said 2018 needed to be the year of change from both the government and the corporate dairy industry.

Photo: RNZ / Rebekah Parsons-King

"Fonterra and Dairy NZ should take note of these results. They show the tens of millions of dollars they've spent on slick PR to try and change people's minds isn't working," Mr taylor said.

But a Fonterra spokesperson refuted Fish and Game's comments.

"Our farmers are working extremely hard to improve the country's rivers. That includes investing around a billion dollars to fence 98 percent of significant waterways, plant riverbanks, build wetlands and install effluent management systems that help prevent nitrogen leaching," they said.

Fonterra said while some of the countries rivers were in a good state, some had been negatively impacted by agricultural intensification, urban expansion and industrial pollution.

"We want to be part of the effort that puts that right," they said.

Fonterra has also announced plans to improve 50 of New Zealand's freshwater catchments.