Fast-track water storage: Irrigation NZ

"New Zealand simply cannot afford to bail out its agricultural industry twice every decade - the recent turn-around for a serious dry spell. Over a billion dollars has already been wiped out this summer through drought. Agriculture is what New Zealand is built on – even Auckland – so combating drought is an issue we all need to get to grips with," says IrrigationNZ chief executive Andrew Curtis.

Curtis says the answer lies with a combination of regional and on-farm water storage development, and with a few billion dollars worth of investment, New Zealand could future-proof its agricultural sector and thus its economy.

"For hill country farms having the ability to store water and irrigate a small part of each farm, as little as 20ha, would create a strategic advantage for New Zealand agriculture. Irrigation enables feed and produce to continue in a consistent and predictable fashion year in year out.

"The North Island would not be in such dire straits if we had water storage on-farm. Winter storage is key for hill country environments as stream flows are often erratic. In short, we need to harvest water from adverse events and store it up for sunny days."

Curtis says recent analysis in the Hawke's Bay, as part of the Ruataniwha storage proposal, showed when sheep and beef farmers irrigated a percentage of their farm they produced a higher rate of return per irrigated hectare than dairy. Irrigation builds in resilience and provides options to a farming system.

"Imagine how much more efficient our meat and vegetable processors would be if drought didn't wipe out crops and stock every five years. It's not just farmers that lose out; it's their staff, the surrounding community and businesses that rely on agricultural income that also suffer."

Curtis says while drought hasn't been declared in the South Island, the dry spell is beginning to hit home.

"With no foreseeable rain on the horizon, South Island irrigators are also starting to feel the pain as river water supplies become restricted and then move to full bans. River-based schemes like Waimakariri Irrigation Ltd have been on restriction, followed by a full ban, for the last month. This has significant economic implications. The scheme calculates around $30million (on and off-farm impacts) has been lost from the district already."

"In contrast, irrigation schemes serviced by the Opuha Dam in South Canterbury won't face restriction until the end of March and then possibly only partial restrictions in April. It's a stark contrast between regions that have access to stored water and those that don't."

Opuha Dam has been able to maintain river flows well above the very low natural flows they would normally experience. The flow in the Opihi River currently would be less than 50% of what it is with augmentation – even if there was no irrigation abstraction.

Curtis says the current climatic situation proves the development of reliable water storage and distribution network should be considered 'a nationally significant strategic investment'.

"Around a billion dollars of investment would future proof Canterbury for the next 100 years. And this investment would be paid back to the community within a decade if the current climatic trend continues."

IrrigationNZ has recently developed an irrigator 'toolkit' and associated training courses for both irrigation development and operation to ensure future irrigation developments are efficient and sustainable. Dryland farmers wanting help with irrigation projects should check out the website www.irrigationnz.co.nz or contact Paul Reese, Project Manager, on phone 03 341 2225 for more details.