A new environmental report has conceded there is no "magic bullet" to fix water pollution in New Zealand.

Parliamentary Commissioner for the Environment Jan Wright today (Tue) released her report - Water Quality in New Zealand: Understanding the Science - which aims to make the science behind water quality more accessible to assist in policy making.

The report outlines the three major pollutants affecting New Zealand waterways, and details how each one impacts the environment.

"Clear clean cool streams full of life flowing through forests still exist in remote parts of the country. It is not realistic to return all our fresh water to this pristine state. But nor can we afford not to act," the report read.


"There is a large menu of interventions that will protect and improve water quality, but there is no magic bullet."

Rather than offering solutions or recommendations, Dr Wright said the report sought to educate people about the cause and effect process of water quality.

"Understanding the science is fundamental ... without understanding the cause and effect we are blind, but we do need to recognise when more science is not needed," Dr Wright said at the report's launch in Wellington this afternoon.

"A call for more science to be done can sometimes be a way of delaying making difficult decisions."

Speaking to media after the launch, Ms Wright acknowledged that the current water pollution situation was something that had to be looked at.

"We have a problem that's become a source of great concern, largely because of the algal growths and the weeds that have developed in some of the places where people would swim and fish, and they remember what it used to be like," she said.

"People are increasingly aware, and efforts are stepping up, but it is not an easy problem to solve."

Ms Wright said another report on water quality was due to be released later this year, and that might consider potential solutions.

"My point here is that solutions that we have must be based on the science, otherwise they're not going to be effective, so we first need to understand that basic science."

Fish & Game NZ chief executive Bryce Johnson said the report made it clear urgent action was needed.

"Too often we encounter calls from polluting industries for 'more science' to prove their activity is having an adverse impact on water quality," Mr Johnson said.

"Yet Dr Wright correctly points out in her report that this is being used as a tactic for delaying difficult decisions."

Mr Johnson said the cases of Waituna Lagoon in Southland, and Canterbury's Lake Ellesmere, deemed as two of the country's most polluted waterways, were examples where such stalling methods had been used.

The organisation laid the blame largely on the agriculture sector, with Mr Johnson saying "Fonterra, Beef and Lamb NZ, the Dairy Companies Association of NZ and the Dairy Environmental Leadership Group can't sit on their hands any longer".

"All need to be requiring environmental best practice from their suppliers, particularly where it relates to effective riparian management where the science is already well established."

Federated Farmers spokesman Ian Mackenzie said his industry should not shy away from its responsibilities, and that "water quality is an issue for all land use, whether urban or rural".

Mr Mackenzie welcomed Dr Wright's report, saying the issue was complex, but all New Zealanders had to take responsibility for it.

"Hopefully this report will encourage more discussion on some of the difficult decisions ahead of us on what needs to be done to remediate waterways, and what costs some suggested actions, such as limiting activities and development, would have on the wider economy."