The Green Party wants all livestock to be fenced out of waterways with a buffer zone between the water and the fence, and the party would introduce a charge on irrigation if it is part of the next government.
Co-leader Russel Norman has today announced the final part of the Green Party rivers policy, at a dairy farm in Raglan.
The National Party has promised to fence dairy cattle out of streams, but Dr Norman said it was a token gesture.
He said the fences needed to be set back from the waterway in order to create a buffer zone of vegetation and the party would set up an expert panel to determine the size of that zone.
"It means obviously that you keep the animals out of the waterways but it also means that you start to intercept some of what's coming over the top it during the rain storms, what's coming over the top of the soil, that's sediment, that's phosphorus, that's the faeces and e-coli."
Dr Norman said the Greens would set up a $100 million fund over three years to encourage farmers to plant in that buffer zone.
He said the Greens would also introduce a charge on water used for irrigation, with the price and method decided after consultation.
Dr Norman said all of the money raised would go toward water clean-up initiatives.