22 Jan 2015

Call for increased irrigation use in Canterbury

8:09 am on 22 January 2015

Dairy farmers with access to irrigation are being spared the worst of Canterbury's dry weather and many are calling for its increased use.

Drought in New Zealand

The National Institute of Water and Atmospheric Research said soil in parts of the South Island was severely to extremely dry compared to an average January. Photo: NIWA

The region, known for its dry summers, had seen more conversions from sheep and beef farming to dairying than anywhere else in the country, something that would not have been possible without water from its mountain fed rivers.

Robert McDowell raised heifers for dairy farms in Mid-Canterbury and was on the board of the local irrigation scheme that took water from the Rakaia and Rangitata Rivers.

He said irrigation changed everything when it came to what could be farmed and where.

"If you've got irrigation, a dry year often can mean better production because you've got warmer weather, better sunlight.

"You finish up growing more in those kind of seasons, as long as you've got the water, than you do in what would normally be considered a wet season."

Mr McDowell said the situation in South Canterbury, where water from the Opuha Dam was about to dry up, could not happen to his irrigation scheme, because it was fed by rain from the West Coast.

"When there's hot northwest conditions and there's heavy rain on the West Coast, that rainfall spills over the main divide into the alpine areas and the rivers that we depend upon for irrigation actually rise and have greater flows.

"That kind of rain doesn't benefit lake Opuha much."

Ngai Tahu Property owns some of Canterbury's largest dairy farms and recently showed an interest in the controversial Ruataniwha Dam in Hawkes Bay.

Chief executive Tony Sewell rejected the idea that dairy farming in Canterbury, with the help of expensive irrigation schemes, was a high-stakes game.

"At the moment with a drought proposed I'd say the stakes are a hell-of-a lot lower than they are with dry land farming.

"We're just managing environmental conditions and man's been doing that for generations.

"There's parts of the world where they're irrigating deserts and growing food."

Mr Sewell said irrigation was expensive and only stacked up financially if the returns were also high.

Drought conditions in mid-Canterbury, January 2015

Drought conditions in mid-Canterbury, January 2015 Photo: Jeremy Talbot

He expected dairying to continue providing these high returns and said the low milk price was only a blip.

"You've got to take a long term view. If you measure the dairy prices back over the past 20 years they haven't looked too bad.

"Bit of a tumble this time but we don't get up in the morning and make our decisions on what's happening on that particular day.

"We've got a slightly more planned approach than that."

Forest and Bird's Kevin Hackwell said taking water from alpine-fed rivers would lead to pressure being put on authorities to allow minimum flow levels to be breached in dry years.

"A lot of pressure will come on to actually put aside the environmental protection. Oh it's just an emergency, just this year.

"Year after year that happens because of climate change and we run the risk that we're going to kill these rivers."

Mr Hackwell said the alluvial nature of Canterbury's soils meant there was a heightened risk of nutrients from dairy farms making its way into waterways and polluting them.

He said the Government was wrong to offer loans for irrigation schemes to encourage dairy farming in areas it was not well suited to.

"The Government's put aside $400 million from the sale of the publicly owned power companies to subsidise irrigation schemes.

"If these schemes are economic, they should be able to fund themselves."

Canterbury's largest irrigation scheme yet, Central Plains, would open its first stage this year in a project that will eventually irrigate 60,000 hectares between the Waimakariri and Rakaia Rivers.

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