"That won't be done through a raw cap on cow numbers; it will be done on nutrient limits, the amount of nutrient that can be lost from a farm to a waterway, because it's not just a dairy cow issue."
Parker also ruled out direct subsidies for land-use change - instead, that could be enabled through new technologies that the Government was "willing to subsidise to bring forward".
When asked what the economic impact for some, particularly dairying regions would be, he said an analysis of the potential economic effects hadn't yet been done.
"But it's very, very difficult to model, because second-best from the farmer perspective may still be very close to the same outcome profit-wise."
Parker said one of the solutions could be a shift, as seen in south Canterbury, toward more cropping and horticulture.
Labour - whose coalition agreement with NZ First vaguely referenced "higher water quality standards for urban and rural using measurements which take into account seasonal differences" - had also pledged in the election to make all rivers and lakes to be swimmable, with extended quality standards.
Federated Farmers water spokesperson Chris Allen called for a more "nuanced" approach than what Parker had suggested.
"When he talked about potentially limiting cow numbers, if that's what it takes, yeah, in some places it might be - but there's much more that goes on in a catchment-by-catchment process where you've got to understand what the soils, climate and rainfall are."
Allen said there was also a need for more science - and for urban areas to address their own water pollution woes as well.
National's economic development spokesperson Paul Goldsmith criticised Parker's comments as "wishful thinking on a grand scale" and likened them to the Government's move to end offshore oil and gas exploration.
"Real economic development is about more than flinging around loose ideas to make up for stopping significant parts of the economy," Goldsmith said.
"For the sake of our regions in particular, this Government has to get its head out of the clouds and start being real."
RMA shake-up due
Meanwhile, Parker said people could expect big changes next year to the country's linchpin environmental legislation, the Resource Management Act (RMA).
Parker told the Herald two stand-out issues to be tackled were the fact it currently took councils too long to change a plan, and that there wasn't enough national guidance on areas that should be standardised across the country.
Most of the bigger changes on the cards were still to be put before the Cabinet, but the Government was already pushing ahead with a series of smaller-scale reforms over the next year.
Some would reverse changes made by National last year, including one that removed appeal rights of applicants and objectors on residential activities and subdivision of land.
"A more comprehensive longer-term review of the resource management system will be considered next year, building on the Government's work on urban development and water issues, and informed by work from outside government."
The work would include a project being undertaken by the Environmental Defence Society (EDS), supported by the Law Foundation, Employers and Manufacturers Association, Property Council of NZ, Infrastructure New Zealand and Watercare and previous work by Local Government NZ.
"The project is taking a first principles look at how the resource management system operates – not just the RMA but the whole system," he said.
"Through all of this, I will be a staunch defender of Part 2 of the RMA – which sets out crucial environmental bottom lines."
Last week, Parker also announced a new bill to amend the Exclusive Economic Zone (EEZ) Act, which would ensure those applying for notifiable marine consents for activities within the EEZ paid for the board of inquiry that considered their applications.
EDS chief executive Gary Taylor welcomed the moves.
Some of the RMA changes made last year had further limited submission and appeal rights, while others gave ministers too much over-ride power, and many had been opposed by a wide cross-section of the community, rather than just environment groups, he said.
"EDS and our business partners are keen to see long-term reform of the resource management system – not just the RMA, but who implements it."
