The rubber hit the road in Horizons Regional Council's second and final day in the Environment Court in Wellington on Tuesday.
The Fish and Game Council and Environmental Defence Society want Horizons to stick to its original One Plan rules limiting the leaching of nitrogen from farms. They have asked the court to make seven rulings that will tighten the way consent is given.
Horizons' counsel Paul Beverley finished his submission and made Horizons officers Nic Peet and Greg Bevin, who handle the consents, available to answer questions.
Pahiatua farmer Andrew Day used an example of the way consents are issued to illustrate his contention that high leachers of nitrogen have an unfair advantage.
Commissioner Katherine Edmonds asked whether those leaching lots of nitrogen could use up a catchment's capacity to cope with it, therefore preventing new players having a go.
Dr Peet said the nitrogen loading capacity of individual catchments had not been determined, but that would have to be done.
Some submitters and one of the commissioners suggested either not giving consents or giving shorter consents with review clauses to avoid future problems with over allocation and inequity.
Environmental Defence Society counsel John Burns asked what factors are considered when officers decide whether to give consent. He said, and Dr Peet agreed, that it would be wrong to consider farm profitability anywhere in the mix.
Questioners tried to tease out whether Dr Peet had suggested councillors consider the profitability of farms when giving consents. He said the council's June 2013 resolution, which made this policy, would be revoked at the full council meeting on February 28.
Staff members would be expected to use the One Plan and Resource Management Act rather than the resolution when making decisions.
He insisted council was still focused on improving water quality in the region. Despite some high leachers making minimal reductions in examples cited, he said nitrogen leaching was down 11 per cent overall.
"In my view council has taken really significant and decisive action and the One Plan has been a catalyst for that. We have 400 farms go from permitted to requiring consent.
"When the One Plan was developed nitrogen loads would have been increasing. Now they're improving or stable."
Mr Bevin gave the example of one consent that has so far been declined, because the proposal would leach too much nitrogen. He expected the application would be changed and come back for consideration in a few months.
Farms that have not lodged consents in time have been given formal warnings. There will be more focus on enforcement this year, he said.
Submitters on behalf of both DairyNZ and Fonterra were satisfied with the way Horizons was granting consents. They said those opposed were attempting to widen the factors to be weighed up.
Richard Gardner, on behalf of Federated Farmers, considered the council was operating within the law.
He said the controversial June 2013 resolution by Horizons councillors was "palliative". It didn't worry him that it would be revoked, because the established pattern would be continued.
He called two farmer witnesses, who had presented evidence and answered questions.
Environment Court Judge Craig Thompson ended the hearing just after five, saying he would receive the closing submissions from Fish and Game and the Environmental Defence Society in writing.
The court's decisions will then be considered, and released in writing. Judge Thompson said they would be important.
"I am conscious of the impact these decisions can have on a lot of people."