Oxford farmer Cameron Henderson's one of many who made the move to Canterbury 12 years ago, at the tail end of what he called “the white gold rush” to convert a farm to dairy.
He says a lot of North Islanders made the move, chasing the opportunity to turn otherwise unproductive dry Canterbury farms into irrigated dairy farms.
Henderson says running a farm has become much more complex since he started.
“When we arrived the key goal was really get as much land as you could and get as much water as you could and just irrigate it and it would grow grass and that was about it,” he said.
The past two decades has seen the region's dairy boom become home to more than a million cows, and newly published research has shown the impact the industry's having on the region's drinking water.
Behind this latest report is Victoria University’s Senior Research Fellow Mike Joy, who says for every litre of milk produced in Canterbury, between 433 to 11,110 litres of water is needed to dilute the pollution it causes.
“What we've highlighted is how much fresh water is harmed in the production of milk in Canterbury, and it's a result of the industrialisation of farming," he said.
“If we had 12 times as much rain, a minimum of 12 times, that would dilute the nitrogen out to safe levels. We don't have that. We're not going to.”
Joy says the best solution is fewer cows.
“What we need to do is reduce the intensity. Reduce the number of cows on the land and that will have advantages for green house gas emissions, nitrate to water, human health harm, right across the range.”
Environment Canterbury Director of Science Tim Davie says the intensification of farming over the last 150 years - and in the last 30 years with dairy - has led to many changes in the way farmers are able to farm.
ECAN admits more could be done but says it has already brought in a raft of regulations.
“We have spent a lot of money over the past 10 years developing a plan that puts in place restrictions on the amount of nitrogen and other losses that come from farming and other practises,” he said.
Over the past decade, ECAN has spent around $60 million developing plans and regulations. They estimate the same amount of investment has been made by farmers to make those improvements a reality.
Just 12 years ago the only requirement to run a dairy farm was an effluent consent. Now, farmers are required by legislation to meet their environmental footprint obligations.
"We have got a consent to farm, a farm environment plan which gets audited every three years, and there's even greater regulation that means we need to reduce our nitrate output from this farm,” Henderson.
Farmers also face tougher regulations in Canterbury dependent on which catchment they fall into.
“A good example is around Lake Ellesmere, where it requires greater restrictions or greater improvements than just the good management practise," Davie said.
In Canterbury, farmers are given the choice for how to reduce their nitrogen losses. It’s up to the individual farmer to choose from the options available to meet that outcome.
“I think the change, while some people might not see it as happening very rapidly, there is a lot of rapid change going on,” Henderson said.
“We have halved our nitrate losses on this farm and that is over a five-year period.”
Henderson said the use of new technology and research is helping improve farm practises.
“Genetics is one of the tools we have already implemented in this farm, so over the last five years we have managed to half our nitrate losses at this property while also increasing our milk production and keeping our cow numbers the same level we had five years ago.”
“We are trying as dairy farmers to do things as fast as we can while maintaining our viability and still contributing to the wider community,” he said.
That's something Joy doesn't agree with.
“We are not feeding the world, we are making a bulk commodity that ends up as junk food overseas and replaces breast milk.”
“This is not feeding the world, this is making the world unhealthy,” he said.
Joy was clear to point out farmers were not in anyway to blame for this. He says the failings are with the government, central and local, to stop this intensification from happening.