Federated Farmers is warning against rhetoric and emotion swaying the decision on large-scale dairy farms in the Upper Waitaki region.
Environment Minister Nick Smith has intervened in three resource consent applications to discharge effluent from farms.
The applications involve nearly 18,000 cows being housed indoors eight months of the year on farms totalling an area of 8555 hectares in South Canterbury. They also involve the discharge of 1.7 million litres of effluent a day.
Dr Smith says he intervened because of the scale of the proposal, the fragile nature of the environment in the region and the high level of public interest.
South Canterbury Federated Farmers president William Rolleston says the Minister needs to be careful and not be influenced by emotion or public opinion.
"There would be a concern if decisions were made that impeded economic growth, which were not balanced by any real environmental issues," he says.
Federated Farmers' dairy chairman Lachlan McKenzie says he hopes the process does not drag on and become too costly for applicants.
"It's a sad indictment on New Zealand if people can't put applications in for lawful use of their land and have that dealt with in due process and a reasonable timeframe."
He said the decision should be based on good science and sound evidence.
Dr Smith says the proposed farms would discharge effluent equivalent to that produced by a city of quarter of a million people.
Mr McKenzie calls this a gross exaggeration and a misuse of facts and figures. He says the area already has animals farmed on it.
He says out the applications involve storing dairy effluent over winter to prevent nutrients entering groundwater or waterways.
Stored effluent would be spray-irrigated onto pasture during the summer when there's low rainfall, and the pasture most needs it.
Dr Smith is standing by the figures and says the amount of effluent produced by each cow is equivalent to that of 14 people.
Salmon farmers concerned
Salmon farmers in South Canterbury fear intensive dairying in Upper Waitaki could hurt their businesses, while environmental and tourism groups believe the proposal could damage the landscape and waterways.
Mount Cook Salmon says the freshwater salmon industry is worth millions of dollars to the region and it relies on pristine water.
Manager Rick Ramsay says the proposed farms are too big and should be scaled back. He runs a fishery near Lake Tekapo and says the high quality water gives the farm an edge.
Benmore Salmon manager Matt Evans says he is worried about more dairying in the region - whether the cows are indoors or out. Mr Evans says all of the salmon farms are expanding and they rely on a supply of pristine water.
Benmore Salmon has a processing factory and employs 30 people. It is the third biggest employer in Twizel with a turnover of $6 million a year.
However, a director of two of the companies behind the proposed farms, Richard Peacocke, says they have robust environmental management plans in place.
Council asked minister to intervene
The Canterbury Regional Council, which normally decides on such applications, asked Dr Smith to intervene and have the Environment Court consider the matter.
The Resource Management Act allows a minister to call in the resource consent process when the applications are considered to be of national significance.
A board of inquiry has also been set up to decide on the applications.
The minister says he chose a board over the Environment Court, as it is more informal and allows better participation by the public without the high legal costs.
Dr Smith expects the board may take up to a year to work through all the issues associated with the consents.
Once the board has finished its hearings, it will issue a draft decision. Councils, submitters, applicants and Dr Smith will then be able to comment before a final decision is made.
Green Party co-leader Russel Norman says the proposed farms would seriously damage the local environment and supports Dr Smith's move.
"The soils are very thin and rocky and putting 1.7 million litres of effluent (on it) a day would inevitably end up contaminating the ground water and the surface water of the region."
Dr Norman is calling on the applicants to now withdraw their applications, so a proper plan for the region could be developed.