The Green Party is touting a Waikato farm as an example of how it wants all farmers to operate.
The Greens announced the final part of their clean rivers policy yesterday which would require farmers to fence off rivers, lakes and wetlands by mid-2017, with a buffer zone for vegetation.
At Mike and Madeline Moss's farm in Raglan, where the policy was announced, about 14 kilometres of waterways are fenced and planted.
Dr Norman wants more farmers to follow their lead. "There's lots of great farmers around New Zealand," he said. "It's just that we've got a government that seems more atuned to doing the worst farming practices rather than those that are doing the best. What we need is a government that rewards those doing the best rather than those doing the worst."
Mike Moss said the benefits had far exceeded our expectations. "So obviously there's the one of no more stock losses and waterways and that's big. Possibly most importantly what we started noticing quite quickly was the improvement in the water quality."
Dr Norman said native freshwater creatures were returning to the farm's waterways, such as New Zealand freshwater crayfish.
"You don't see a lot of them around anymore because, of course, of the deterioration in our waterways. They're coming back on Mike's farm because Mike's done this to the creek, he's protected it," Dr Norman said.
The Greens would set up a $100 million fund over three years to encourage farmers to plant in the buffer, or riparian, zone.
It would also introduce a charge on any water used by farmers or other commercial operators for irrigation, with all the money raised going toward cleaning up waterways.
Fred Lichtwark has spent the past 20 years planting native trees along the streams and edges of bays in the area.
He said the planting had transformed Raglan Harbour from the worst in the country to one of the best.
"It ends up with shade and shelter for stock. You get more bees so you end up with more clover pollination. You don't lose stock directly in wetlands. There's huge advantages for farmers to be doing this work. It's not a green, fuzzy thing at all. It's increasing productivity and it just so happens it's a win, win, win."
National Party leader John Key said the Greens' plan was extreme and would impose a massive costs on the agriculture sector.
"The Greens are very binary. It's either yes or no. They're essentially saying no to agriculture in an affordable way in waterways that it wouldn't make sense," Mr Key said.
But Mike Moss said the cost had been minimal, and maintains the plan is affordable. "If I sat down and worked out the return on my investment, it would be pretty darn good."