Labour would make it tougher for farms to intensify operations under a 12-point freshwater policy launched in Havelock North this evening.
The party's policy seeks to crack down harder on polluters, make all rivers and lakes swimmable and extend freshwater quality standards.
Environment Minister Dr Nick Smith has criticised the policy as "vague" and says it "fails to pass the fairness test".
At the policy's core is a new National Policy Statement (NPS) for Freshwater Management, based on principles recommended eight years ago by former head Environment Court Judge David Sheppard.
Under the NPS, any further increases in farming intensity, including more livestock, irrigation or fertiliser per hectare, would no longer be a "permitted activity".
"So if you are going to turn an ordinary piece of pasture into a feedlot, or a low density farm into a high density farm with food supplements or irrigation, you'll need a resource consent - and sometimes you won't get it," Labour environment spokesperson David Parker said.
The new NPS would also require rivers and lakes be clean enough for people to swim in during summer without getting sick.
Parker said more than 60 per cent of monitored freshwater sites were graded poor to very poor for swimming, while, since 2008, stress from dairy farming had worsened, with an additional million dairy cows producing the equivalent waste of 14 million humans.
The party would adopt freshwater quality standards that covered pathogens, dissolved oxygen, nutrients, periphyton and macroinvertebrate health, with bottom lines to reduce diffuse pollution of freshwater by set deadlines.
Labour would require all intensively stocked land near waterways to be fenced off within five years, and fund either the Ministry for the Environment (MFE) or the Environmental Protection Authority to enforce the law by prosecuting breaches of the Resource Management Act through local Crown solicitors, including the right to reclaim costs from the guilty party and the regional council.
Further, the Audit Office would be ordered to audit annually every regional council as to whether they were properly carrying out their legal responsibilities to protect freshwater, Parker said.
Each regional council would be made to report annually to MFE on whether, and how, city or district council rules within the region were adequate to protect waterways.
"Some regional councils have been farmer dominated and they've never been given a budget for their staff to prosecute - therefore their plan is not enforced," Parker said.
"I know that people are really pissed off that their rivers are being wrecked by some irresponsible farmers - and they want their politicians to help fix it."
To prevent the extinction of freshwater species, the party would also consider whether a moratorium on commercial fishing was needed.
"We'll really give it serious consideration because it's terrible that we've got some of our native species threatened with extinction," he said.
"But I think in the end the bigger cure here is water quality."
Responding to the policy, Smith noted none of the 12 points in the plan mentioned urban quality, "yet independently verified reports show water quality in towns is worse than in the country".
"The Government's plan requires both farmers and townies to do their bit to improve New Zealand's water quality."
Smith said the policy was "so vague it will actually slow progress in improving water quality".
"For instance, they say they will require intensively stocked land to be fenced within five years, but don't bother to define what intensively stocked is."
He questioned how all waterways could be made swimmable in summer when rivers naturally flooded, and how Labour would pay for the work.
The Government's own Clean Water Package includes a target that 90 per cent of our rivers and lakes are swimmable by 2040, with an interim target of 80 per cent by 2030.
It also included better information on water quality for swimming, proposals for changes to the National Policy Statement for Freshwater Management 2014, details of proposals to exclude stock from waterways, and the $100 million Freshwater Improvement Fund.
Choose Clean Water spokeswoman Marnie Prickett said she wanted to see some more detail around Labour's policy, but supported its inclusion of limits for pollutants phosphorous and sediment.
"Along with E. coli, phosphorous and sediment also have an effect on whether rivers are swimmable or not," she said.
"Phosphorous is one of the drivers of algal blooms and having low E. coli but a river full of dirt or slime isn't the vision New Zealanders have for their rivers."
Prickett is part of a consortium of groups and sectors that yesterday launched the Freshwater Rescue Plan.
Its seven recommendations include immediate strategies to decrease cow numbers, a "polluter pays" system to reduce contamination and to withdraw public subsidies of irrigation schemes.