Frost Protection – Resource Consents for Wind Machines
In recent years, wind machines to help protect kiwifruit crops from frost damage have been installed in the Bay of Plenty following damaging spring frosts. Unfortunately, their popularity was not anticipated during the formulation of the Western Bay of Plenty District Plan, and noise and resource consents have quickly become an issue. Conflict has arisen between the cost of frost damage to growers and the regional economy and night-time noise from wind machines disturbing sleep. Ruth Underwood reports on the issues and progress with resource consents for wind machines in the Bay of Plenty region.
Most frosts are radiation frosts that occur during a cool night after a clear, fine day. A low-lying layer of cold air does the damage, but is overlaid by a layer of warmer air. Wind machines or helicopters mix the warm air through the cold air, thus raising the temperature in the orchard and protecting the young flowers, fruit and shoots from frost.
Spring frost damage to a kiwifruit orchard at pollination time in late November 1994. Foliage was burnt and many of the flowers fell off or failed to develop properly due to the frost damage.
Surviving kiwifruit are often deformed after spring frost damage. Normally developing fruit are shown to the left of the film canister.
A number of growers have used helicopters for frost control. Because they are mobile, they appear to be exempt from noise levels specified in the District Plan and thus do not require a resource consent. However, helicopters are costly, and the decision whether to have one on standby each night has been described as “gutwrenching” by growers. There have also been failures with the booked helicopter being unavailable on a frosty night.
Thus more orchardists have turned to using permanent wind machines for frost protection. They consist of a fan mounted on a tower around 5m high, with a diesel motor and automated operation. They can be installed without needing to run wiring to the site, and simply require access by truck and a concrete mounting pad. They cost around $40,000 and protect around five hectares of crop.
The wind machines require a building consent for construction and a resource consent for operation, both from the local district council. A number of these machines have been installed without consents, in some instances because growers were unaware of the need. There have also been instances of machines gaining a building consent without growers being advised of the need for a resource consent, and of growers installing the machines just in time for spring frost protection before seeking a consent. Complicating things, there were no guidelines for issuing consents until mid-2000.
Wind machine protecting kiwifruit and persimmon crops.
Concerns about operation are due to the noise the fans make and their operation during the night hours. Intensifying noise concerns are the proximity of some orchards to a large numbers of neighbours and the fact that frosty nights tend to be consecutive.
The guidelines for frost control fans issued by the Council, but operating outside the District Plan, include a performance standard. If applications are assessed to meet the standard, including written permission from all neighbours in a specified area, then a non-notified consent is issued. These consents incur Council fees of around $400. The consents are issued for an unlimited time.
Notified consents are required where a neighbour’s permission is not given. These take longer to establish – three months is likely in addition to the time preparing an application – and only one has so far been issued. Neighbours concerned about noise included farmers concerned about the effect of noise on nearby stock and residential neighbours. Conditions attached to the notified consent included specified temperatures for both starting and stopping fan operation, a maximum of 10 nights’ operation per year and an alarm at the orchardist’s dwelling to alert them that the fan is in operation. These conditions seem a reasonable compromise between the orchardist’s need for frost protection and the neighbours’ need for undisrupted sleep hours. A different orchard has used its fan four and five times in the last two seasons so it is unlikely that more than 10 uses will be sought.
For notified consents, Council fees increase to around $2,000 and the grower is more likely to engage a planning and/or noise consultant to help present their case.
Unconsented fans are being dealt with by the Council as complaints arise and those orchardists are being requested to apply for resource consent. In general, there have been more complaints about unconsented than consented fans, probably due to unconsented fans being sited solely for frost protection rather than also considering noise at nearby dwellings. The most complaints have been about a fan sited 80m away from 20 houses but complaints have arisen about fans three kilometres away.
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Ruth Underwood MAF Policy Agent Tauranga Ruth Underwood is a Horticultural Consultant with Agriculture New Zealand in Tauranga and is also contracted as a MAF Policy Agent. Her background is in horticulture, with 15 years’ experience including field reporting and industry analysis for policy purposes, contributing to MAF’s Kiwifruit Financial Monitoring, horticultural consultancy and facilitation. She is a Massey graduate, completing an Honours degree in Horticultural Science in the mid-1980s. |
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