Parker indicated the shift in approach in an address to a Catchments Otago symposium on water and biodiversity issues, hosted by Otago University.
He said he will get off the back of rural New Zealand when he sees water quality is no longer deteriorating.
“If we can’t get a collaborative outcome from stakeholders, someone has to make a decision and I’m prepared to be that person.”
The country’s recent economic growth had been at the expense of the environment, especially through the expansion and intensification of dairy and Parker was unequivocal that will no longer be the case.
Behavioural change will come only through education, regulation and price and Parker said regulation to improve compliance, monitoring and enforcement is the most important instrument.
That will be driven through changes to the National Policy Statement on Freshwater.
The document established national standards to be applied locally for emissions such as nutrient and sediment discharges, land intensification and deadlines for improvement.
Parker said he is also seeking scientific advice on appropriate nutrient and sediment loadings, the impact of beef feedlots, intensive winter grazing and cattle in waterways.
He told the 70 delegates his priority is to stop further degradation and said agriculture will have a generation to reverse damage to waterways but he expects to see some material improvement within five years.
Land use and land management decisions are the most common cause of water quality degradation and it has been exacerbated by agricultural intensification and what he called poor land practice by some.
The speed with which dairying expanded caught local and central government by surprise as the sector sought to produce dairy products for Asia but now exceeds carrying capacity in some areas.
Parker believed possible solutions are to shift to high value horticulture and cropping.
Some of the most heavily polluted waterways are in urban centres and Parker said one of the worst is Auckland.
In response to public outcry over the constant polluting of beaches, he said the Auckland Council has brought forward plans for an $860-million, 10-year project to separate sewage and stormwater overflow systems.
He was unapologetic for the announcement the Crown Irrigation Fund is being wound up, putting three South Island schemes at risk, saying the Government should not be subsidising irrigation schemes.
Small scale community water storage schemes that benefit the community and environment can, however, get funding through the Provincial Growth Fund.
The Kurow-Duntroon irrigation scheme has been spared but irrigation company chairman Geoff Keeling said its Government funding will be repaid with interest “just as a private loan would be, so the taxpayer benefits from this investment as well as the local community”.
Speaking after his address, Parker said farmers have to operate within environmental limits and those who are careful with their environmental management are being threatened by those who aren’t.
He also acknowledged cattle and deer are largely excluded from waterways, especially dairy cows on milking platforms, but there is still concern about sediment from winter grazing units seeping in to streams and rivers.
But fencing is unlikely to be a requirement in low-stocked, back-country rivers.
