Joint project researches wind damage to irrigators

Catch-up . . .People attending Irrigation New Zealand's Great Irrigation Challenge in Ashburton...
Catch-up . . .People attending Irrigation New Zealand's Great Irrigation Challenge in Ashburton socialise over lunch. PHOTO BY MAUREEN BISHOP
Last year's windstorms, estimated to have damaged more than 800 irrigators, have prompted an insurance company and Lincoln University to work together to investigate how farmers protected their irrigators.

FMG Insurance and a research team at the university are surveying more than 400 farmers in the hope of providing advice and reducing the risks of damage to irrigators in the future.

Speaking at the Great Irrigation Challenge held by Irrigation New Zealand in Ashburton this month, loss adjuster Philip Grose said FMG had 261 claims for damaged irrigators at a total cost of $7.6 million.

Ninety percent of the irrigators were repaired within seven months, Mr Grose said.

The windstorms were estimated to have cost the insurance industry $68 million in claims, with 1000 clients affected and 2400 claims for buildings, houses and irrigation equipment.

Kevin Malcolm, FMG's business development manager based in Oamaru, said preliminary results from the survey showed 58% of irrigators had no damage.

Of the others, the damage was to corner arms in 25% of cases, the complete system in 23% of cases and the last few spans in 24% of cases.

The survey indicated that pointing the irrigator longitudinally in a downwind direction would reduce the surface area exposed to the wind, Mr Malcolm said. Seventy-five percent of clients who did this did not have a claim.

Farmers should create at least one parking space on the farm and move irrigators into the space in the off season or when severe weather warnings were released.

Anchoring the irrigator would also help, along with protecting corner arms and overhangs.

The worst angle between spans or corner arms and the wind direction was 90 degrees.

Mr Malcolm acknowledged it was often hard to move irrigators into line or out of the wind, but they should be anchored as well as possible.

Other issues affecting irrigators were the slope and gradient of farms, the position of neighbouring shelter belts, and the location of undulating hills or surrounding valleys.

Irrigation systems close to rivers suffered severe damage because the wind funnelled down river beds, Mr Malcolm said.

The effectiveness of a windbreak in reducing wind speed depended on the density, height and orientation of the windbreak.

Narrower wheelbases would give less support during windy conditions.

Farmers said deflating the tyres had helped but it might not be practical to deflate them all and might even be dangerous.

In Nebraska, where wind was also a problem, pivots were typically 400m in length, whereas IrrigationNZ advocated no longer than 600m due to water efficiency, Mr Malcolm said.

The results of the survey are due to be released at the end of the month.

BY MAUREEN BISHOP 

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