RM Issues

This section outlines the nature of the agricultural aviation industry operators, the potential environmental effects from these operations, and the challenges this presents for developing appropriate management approaches under the RMA. It also outlines the key resource management issues associated with the agricultural aviation industry and some important considerations when developing methods and provisions to address these issues.

The nature of agricultural aviation activities

In order to develop appropriate management methods and controls under the RMA it is important to understand the outcomes sought from agricultural aviation operations and the numerous parameters affecting these operations. This is because the outcomes councils are seeking to achieve when managing the effects of industry discharges are often similar to the outcomes industry is seeking to achieve through discharging the selected product.

For an aerial agricultural application to be successful it is dependent on accuracy:

  • The right product being discharged at the right rate.
  • At the right place.
  • At the right time.

The challenge is to develop appropriate provisions and conditions that adequately provide for this successful application in a way that achieves councils’ outcomes in terms of managing the potential adverse effects from the aerial application of the selected product.

Importantly, no two situations will be the same for the aerial application of fertilisers, agrichemicals and VTAs and an operator must assess a range of variable factors to ensure that an accurate application is achieved.

The key variables affecting aerial applications relate to weather conditions (e.g.: wind speed and direction, and temperature), the target plants or animals, and the nature of the target area and surrounding location. To assist in achieving accuracy and to manage risks, aerial operators use a range of tools and methods such as GPS, calibration, nozzle selection, and pattern testing to certify equipment swath width and spread evenness. Operators also seek to undertake their activities only when the weather conditions suit. The assessment of a specific situation will determine which tools an operator uses to address the risks that the situation presents.

Public perceptions of the industry can be exacerbated by the visibility of an aircraft discharging substances and the height and speed at which a discharge is made. For example, a low-flying aircraft may lead to the perception that the degree of risk and potential adverse effect is significant and therefore the activity should be highly regulated.

Confusion can arise from the variable use of terms to describe or refer to the same substance which can raise concerns and have implications on the management approaches for that substance. For example, is the substance a pesticide, an agricultural compound, an agrichemical or a hazardous substance? Appendix 3 in Technical Information relating to the Agricultural Aviation Industry demonstrates the linkage between the various terms.

The issues above and the fact that there are a range of variables affecting industry operation presents a challenge for councils in developing plan provisions and controls that both provide flexibility for different situations, while providing enough certainty to achieve the outcomes sought. A risk assessment/management approach by the party carrying out the operation – in this case the aerial operator – is an effective approach to manage these issues. This approach also provides flexibility in how desired outcomes are to be achieved which is important given the range of variables involved. This approach has proven to be effective because it deals with specific situations to allow decisions to be made to address the risks and potential adverse effects that situation presents and achieve the outcomes sought by the industry and councils.

Resource management issues and potential adverse effects from agricultural aviation activities

There are a number of key resource management issues and associated effects related to agricultural aviation activities that councils need to consider and manage. This includes:

  • Off-target drift and potential adverse effects.
  • Discharges into water bodies.
  • Advice and information before and after discharges.
  • Reverse sensitivity effects.
  • Amenity issues such as noise.
  • Effects on Māori cultural values.

The focus of the RMA is on managing the risk of environmental effects of an activity, rather than the activity itself, which is consistent with an outcome based approach sought by the industry. In terms of the discharge of agrichemicals, fertilisers or VTAs the potential adverse effects that need to be considered and managed include:

  • Health effects.
  • Contamination of crops and plants.
  • Contamination of domestic or commercial water supplies.
  • Contamination of indigenous flora and fauna, habitat areas and reserves.
  • Contamination of wetlands, surface water body and coastal and marine environments.
  • Contamination of groundwater.
  • Contamination of soils/ land.
  • Amenity values where the discharge creates an offensive and/or objectionable effect.

It is important to consider the scale and significance of the actual and potential adverse effects when developing plan provisions and imposing resource consent conditions. While agrichemicals, fertilisers and VTAs can all have adverse effects, the nature and degree of the potential adverse effects varies considerably due to the different nature of the substances and the sensitivity of the receiving environment the discharges are occurring within. For example, agrichemicals are designed to control pests whereas fertilisers are designed to assist plant growth. Both products have the potential to cause adverse effects through off-target drift but the consequences of such drift are significantly different. Agrichemicals are likely to damage a non-target crop but fertilisers are unlikely to cause such damage, although off-target drift of fertiliser onto an organic property could affect the organic registration of the property.

It is also important to consider area-specific situations when developing plan provisions and imposing resource consents. For example, the use of agrichemicals and VTAs is necessary to control weeds and animal pests in some areas that contain indigenous flora and fauna (such as in wetlands and on the Conservation estate).  

The substance specific sections on fertilisers,agrichemicals and VTAs in this guidance note outline the nature of these substances and their potential adverse effects in more detail.

Potential for adverse effects from off-target drift

The two pathways that adverse effects may occur as a result of aerial application are direct application and indirect application, more commonly known as “off-target drift”. Off-target drift is where the substance being applied ends up in a place other than the target area. It can occur in both fertiliser and agrichemical applications, but the potential for off-target drift is less for VTAs because of the physical properties of the substance (i.e. large particle size and predictable trajectory from the point of release).

An operator seeks to apply the product at the correct rate to the target crop or area, so adverse effects from direct application should generally not arise. However, due to the range of variables affecting these operations off-target drift will inevitably occur in some situations and this is the most likely cause of adverse effects. Off-target drift is a key resource management issue for the industry because of the potential adverse effects that may arise, particularly in sensitive areas where people, water bodies and non-target property are exposed to the discharge. Off-target drift is also a major source of complaints associated with aerial applications.

The approach should focus on ways to minimise the risk of off-target drift and the potential for adverse effects from this drift on surrounding areas. It is appropriate for councils to identify this as an issue and include supporting methods in plans to manage the potential adverse effects. However, determining how off-target drift occurs and how best to manage and avoid it is not a simple matter as there are a range of variables which all contribute to its occurrence, to a greater or lesser extent, depending on the circumstances. The five groups of important variables that contribute to off-target drift are:

  1. Chemical composition (e.g. formulation or product type).
  2. Physical characteristics
  3. Release position (i.e. height above the ground /target).
  4. Interception (by the target).
  5. Meteorology (wind speed and direction).                                  

These variables are either:

  • “Pre-determined factors” – factors that do not change once the application has begun (e.g. spray nozzle type and hence droplet size); or
  • “Real-time factors” – factors that can change while the application is occurring (e.g. wind speed and direction).

The distinction between pre-determined and real-time factors is important because the most significant factor causing adverse effects from off-target drift is almost always wind direction – a real-time factor. Further information on off-target drift is included in the Technical Information relating to the Agricultural Aviation Industryon the NZAAA website and the substance specific sections for agrichemicals, fertilisers and VTAs in this guidance note.

Potential for adverse effects from discharges into water bodies

Discharges of agrichemicals and fertilisers close to water bodies can be a resource management issue where these may enter water or onto land that enters water. Where this occurs, these discharges have the potential to cause adverse effects on the quality of the water body and its ecosystems, and on uses of the water body (e.g. drinking water supplies, irrigation). These discharges can occur through either direct application or indirectly through off-target drift.

Clear identification of water bodies and the proximity of aerial applications to these water bodies is a critical part of identifying the potential risk of direct application and off-target drift and ensuring that appropriate measures are taken to avoid discharges to water or onto land that may enter water. Some plans include specified setback distances as a means to reduce the risk of discharges entering water bodies. However, there often needs to be flexibility to ensure the setback distance can be varied and targeted to the circumstances of the individual situation based on the actual level of risk of discharges entering into the water body. Other activities associated with aerial applications, such as loading and mixing sites, also need to be located and managed to avoid potential adverse effects on water bodies.

Notwithstanding the above, there may be situations when substances are required to control weeds in wetlands. Aquatic herbicides are an example of one type of substance. The use of aquatic herbicides onto or into water is not a matter for regional and district plans as it is controlled by the EPA pursuant to section 95A of the HSNO Act.

The need for information and advice about discharges (e.g. notification)

People who may be adversely affected by an aerial application of agrichemicals, fertilisers and VTAs often want to be notified before a discharge is to occur and provided information on the nature of the discharge. Notification, or lack of it, is often a source of complaints about discharges from aerial applications. Providing this notification and information often influences the perception and concerns of people about the aerial application so the provision of timely and appropriate advice can help address this issue and the potential for complaints/concerns. However, providing information and advice raises a range of issues relating to the different methods used, and the various obligations and responsibilities of councils, landowners and aerial operators.

For agricultural aviation operators, providing early notification of their operations can be problematic because operators fly onto a property to complete a task but do not meet directly with the neighbours or surrounding land owners. However, in the event of a complaint it is usually the aviation company that is identified. It is therefore important to obtain clarity and certainty about the obligations and responsibilities for notification of aerial applications. This should clearly identify who is responsible for undertaking the notification, who will be notified, the form of notification and the timeframes for this notice (this may be controlled under HSNO).

Potential for reverse sensitivity effects

Reverse sensitivity is a key resource management issue for a number of rural activities, including the agricultural aviation industry. Reverse sensitivity refers to the situation where new, incompatible activities constrain the operation or expansion of existing lawfully established activities. The new activity is “sensitive” to the effects of the existing activity, which can result in complaints to councils, and the risk of constraints being placed on those lawfully established activities.

In respect of agricultural aviation, reverse sensitivity usually involves complaints about the aerial application of agrichemicals, fertilisers and VTAs even though it is undertaken correctly (e.g. people may be concerned about the idea of it, or concerned by the noise or effect on their amenity in general). It is a particular issue in rural-residential areas or where the urbanisation of fringe areas has occurred. Reverse sensitivity can also occur between primary production activities, where one activity is sensitive to the substances being applied (e.g. vineyards amongst pastoral land uses or organic properties).

To help avoid reverse sensitivity, councils need to consider the compatibility of activities in different areas and their potential sensitivity to one another in order to reduce the potential for reverse sensitivity complaints. For more information see the ‘reverse sensitivity’ section of this guidance note.


The main potential adverse effect on amenity is associated with aircraft noise from aerial applications which can lead to concerns and complaints. The RMA limits councils to addressing the effects of aircraft noise at take-off and landing, not while in flight. It is important to acknowledge and communicate this to those who may raise concerns about the noise of aerial applications to help reduce the potential for complaints and concerns from surrounding land-uses. For more information see the ‘aircraft noise' section of this guidance note.

Considerations in developing methods and plan provisions to address identified issues

Developing effective and appropriate plan provisions to manage agricultural aviation activities is complex as there are multiple variables that need to be considered for any aerial application. It is important to avoid overly complex and prescriptive plan provisions and consent conditions so there is an inherent tension about how to develop simple plan provisions and controls to manage a complex and variable activity. To ensure appropriate methods and plans provisions are developed there are a number of key considerations:

  • Avoid duplication with other legislation, and only impose additional controls in plans where controls under other legislation are considered insufficient (refer to the section 32 evaluation discussion in ‘implications for planning under the RMA’).
  • Ensure provisions recognise the multiple variables involved in aerial applications to ensure there is enough flexibility to accommodate different circumstances.
  • Use a risk assessment/management approach expressed through controls and appropriate performance standards aimed at achieving clear outcomes sought.
  • Provide alignment and consistency across regions and with adjoining councils where appropriate to avoid complexity for operators who work in a number of regions.
  • Ensure there is recognition of the positive effects of agricultural aviation, such as pest control, increased or improved primary production and public health, when managing potential adverse effects from the industry.
  • Ensure management controls and conditions are achievable and verifiable and do not impose undue constraints or compliance costs.
  • Recognise that fertilisers, agrichemicals and VTAs are different so if they are to be managed in regional plans different provisions may be required for the different types of substances.
  • Provide information on industry best practices and standards.
  • Develop provisions that provide the flexibility to adapt over time and use best practice according to the circumstances of the situation.

The substance-specific sections in this guidance note provide more guidance on developing plan provisions to manage the adverse effects of discharging agrichemicals and fertilisers from air and background information on VTAs. The ‘use of land’ section provides more specific guidance on managing amenity and reverse sensitivity issues associated with the industry’s land-based activities.