It was estimated the change would cost irrigators $300 million.
All parties to the appeal agreed an error in law had been made when the panel introduced it as a new requirement because no submitter had asked for the change.
IrrigationNZ tested 300 irrigation systems in Ashburton and Selwyn districts over two summers and found older spray irrigation systems can achieve good levels of water efficiency if regular checking and maintenance is done.
“IrrigationNZ spent a lot of time on this appeal,” chief executive Andrew Curtis said.
“We knew the decision by the hearing panel would have wide-ranging impacts so we commissioned an independent Aqualinc report, which showed there were huge costs to implement this change.
“We are very pleased that the appeal has ruled out this rule that no one requested,” he said.
The rules around irrigation systems will now be the same as those notified in the Plan Change consultation. The new rules will still require older spray irrigation systems operating on light soils be upgraded and are estimated to cost irrigators about $80m.
Irrigators are already investing in modernising their systems as they age and need replacing. That is reflected in Agricultural Production Census data showing the amount of Canterbury land irrigated with modern spray systems increased from 89% in 2012 to 95% in 2017.
Worldwide, only 14% of irrigated land is irrigated with spray or drip systems and 86% of land is irrigated through flood systems, which are less efficient.
IrrigationNZ said there is still a lot of work to be done to on more detailed requirements around nutrient modelling for irrigation.
“As part of their Farm Environment Plan irrigators have to show how they are achieving good management practice across a range of areas like irrigation, nutrient and effluent management, erosion control and fencing off waterways.
“We have had concerns since the Plan Change was notified that the nutrient modelling rules for irrigation are too simplistic.
“Good management practice varies from farm to farm depending on soil types, crop types and rainfall zones and the rules need to reflect this,” Curtis said.
“However, we are confident we can work through these challenges and find a solution as part of a working group which Environment Canterbury plans to re-convene.
“Farmers and growers across Canterbury have some very ambitious targets to meet around reducing nutrient losses under Environment Canterbury rules and will be devoting significant time and resources to meeting these rules.
“We will continue to support them with training and advice on how to meet good irrigation practice requirements,” he said.
