Irrigation New Zealand

An appeal to Environment Canterbury’s Plan Change 5 nutrient modelling rules has been resolved with a major win achieved for irrigators, says IrrigationNZ.

A Hearings Panel on the Plan Change proposed a new requirement that would have effectively required that all older spray irrigation systems in Canterbury be replaced with new ones by 2020. It was estimated that this change would cost irrigators $300 million.

All parties to the appeal agreed that an error in law had been made when the Hearing Panel introduced this as a new requirement because no submitter had asked for this change.

INZ carried out testing on 300 irrigation systems in Ashburton and Selwyn districts over two summers recently which found that older spray irrigation systems can achieve good levels of water efficiency if regular checking and maintenance is carried out.

“IrrigationNZ spent a lot of time on this appeal. 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,” says Andrew Curtis, Chief Executive of IrrigationNZ.

The rules around irrigation systems will now be the same as those notified in the Plan Change consultation. These new rules will still require that older spray irrigation systems operating on light soils be upgraded and are estimated to cost irrigators around $80 million.

Mr Curtis says that irrigators are already investing in modernising their systems as they age and need replacing. This is reflected in Agricultural Production Census data which showed that the amount of Canterbury land irrigated with modern spray systems increased from 89% in 2012 to 95% in 2017. Worldwide, 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 says 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,” says Mr Curtis.

“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,” he adds.

“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,” Mr Curtis adds.

The parties involved in the appeal were IrrigationNZ, Barrhill Chertsey Irrigation, Dairy Holdings, Rangitata Diversion Race, Federated Farmers, Forest and Bird,Ngāi Tahu, Neil Barton and Environment Canterbury.