9. Managing Adverse Effects on the Transmission Network
9.1 Objective: Incompatible Activities
In general terms, the aim of an NPS in relation to managing effects of activities on the transmission network is to ensure that local authorities recognise and manage the potential for certain activities to disrupt, or risk disruption to, the safe and efficient operation of the transmission network.
Maintaining safety is a related and significant issue.63 There is risk to public safety associated with any high voltage transmission line. It is a risk that can be managed, provided appropriate standards are established and adhered to.
If an objective was to be identified to relate specifically to this issue, it could simply state:
The protection of the electricity transmission network from the effects of activities that could disrupt the efficiency and reliability of its operation.
9.2 Evaluation of Appropriateness
The objective is appropriate in terms of the purpose of the RMA since section 5 (2) (c) refers to avoiding, remedying, or mitigating adverse effects on the environment. The environment can include the environment enjoyed by an existing activity. Furthermore, the environment is defined to include physical resources which, as discussed earlier, includes the transmission network.
The objective, is therefore also appropriate in terms of section 7(b) of the Act which requires all persons exercising functions to have particular regard to the efficient use and development of natural and physical resources.
9.3 Policy: Activities under and around Lines
As noted earlier, landowners affected by existing (pre-1988) lines generally do not have easement agreements with Transpower that formally recognise the limitations on land use associated with hosting a transmission line.
They, and Transpower, are therefore in a situation of uncertainty as to what rights and obligations they do, and do not have. An NPS might acknowledge that situation by containing a policy that encourages local authorities to effectively codify the rights and obligations of the parties.
There are several ways in which this might be done. Each of these options is discussed as follows.
9.3.1 Option (a): A General Policy Requiring Plans to Address the Issue
An NPS policy could be phrased broadly so as to provide local authorities with the clear mandate to protect lines from incompatible activities. Such a policy might read:
District and regional plans should recognise the potential for activities under and adjacent to transmission lines to adversely affect the transmission network and to pose a risk to personal and public safety.
9.3.2 Option (b): A Policy Specifying the Effects to Be Avoided
A greater level of direction could be achieved by a policy that referred specifically to the effects to be avoided. For example, a policy might state:
District and regional plans should ensure that the following actual or potential adverse effects on transmission lines are avoided [remedied or mitigated]:
- risk to the structural integrity of pylons;
- reduction in the vertical safety distances from the ground level to the height of the conductors;
- restrictions in the ability to access lines and pylons for maintenance purposes;
- accumulation of dust on lines and conductors; and
- risk to people's health and safety, interference with radio communications networks and transmission lines and other effects associated with reverse sensitivity.
9.3.3 Option (c): A Policy Specifying the Activities to Be Avoided
More certainty could be provided by a policy that included reference to the specific activities to be controlled. This could be based on the terms of a draft model easement agreement negotiated between Transpower and Federated Farmers in respect of post 1988 lines. Reflecting the model easement agreement64 such a policy might read:
District and regional plans should recognise the potential of the following activities to place the safety and reliability of the transmission network at risk when carried out within a buffer area extending [x] metres either side of the centre line of a transmission line:
- alteration of the grade or contour of the surface, except in the course of normal farming and grazing operations;
- erection of any building or other structure;
- planting of any vegetation;
- operation of any equipment or vehicles within a minimum clearance distance of [y] metres from any electricity transmission conductor;
- excavation or deposition of material;
- any activity that would cause flooding; and
- the lighting of any fires or burn-off of vegetation (within 500 m of a buffer area).
9.3.4 Option (d): A Standard (NES) Based on Existing Restrictions in NZECP 34
A further option is to use an NES to specify the activities that are prohibited or which require consent (and the type of consent, and matters of control or discretion that should apply) in order for effects on the transmission network to be adequately assessed.
This could be based on the existing NZECP 34. As noted in section 4.5.2, NZECP 34 is an existing restriction that addresses the risk of electrical hazard. While NZECP 34 does not aim to address the full range of activities that might affect the transmission network, its focus on managing risk from electrical hazard means it does control many of the high risk activities (in terms of potential effects on the network).
It would be inappropriate to turn NZECP 34 into an NES in its entirety,65 however, it would be possible to design an NES to manage effects on the transmission network to reflect some of NZECP 34's key controls. In short, the standards in such an NES would be the same or similar to those in NZECP 34 but the purpose of those standards would be somewhat broader - reflecting the broader purpose of the RMA.
This would result in an NES that had the following components:
Requirements Relating to Building Activity within Specified Distances from Support Structures and Conductors
In accordance with the existing design of NZECP 34, the minimum distances would vary according to the type of support structure, the voltage of the line, and the span (distance between support structures). Minimum safe distances between buildings and support structures is currently set out in Table 1 of NZECP 34. Minimum safe distances from conductors are currently set out in Tables 2 and 3 of NZECP 34.
The NES could (a) specify areas within which buildings are prohibited; and (b) specify other areas within which buildings would require a resource consent. Where a resource consent is required, the NES could specify the type of consent (i.e. controlled, limited discretionary, discretionary or non complying) and associated requirements.
Requirements Relating to Land Disturbance (Excavation, Contouring etc.) within Specified Distances of Lines
The distances that apply would depend on the distance from the support structure and depth of excavation. These are currently summarised in Figures 1 and 2 of NZECP 34.
The NES could specify other areas within which excavation would require a resource consent. Where a resource consent is required, the NES could specify the type of consent (i.e. controlled, limited discretionary, discretionary or non complying) and associated requirements (such as the matters over which local authorities retain discretion).
Requirements Relating to Stockpiling (Deposition) under Transmission Lines
Again, the distances set out in NZECP 34 (Table 4) vary depending on line voltage, and the nature of the land on which the material is deposited (e.g. whether it is traversable by vehicles). The NES could be based on those thresholds.
The NES could (a) specify areas within which stockpiling is prohibited; and (b) specify other areas within which stockpiling would require a resource consent. Where a resource consent is required, the NES could specify the type of consent (i.e. controlled, limited discretionary, discretionary or non complying) and associated requirements.
Further work would be required to determine which category of consent is most appropriate but it is likely that a full range from controlled activity to prohibited activity status would be required to accurately reflect the existing intent of NZECP 34.
9.3.5 Option (e): A Combination of Option (d) with One or Other of Options (a)-(c)
There is, of course, the option of having both an NPS to provide the broad policy framework and an NES to provide a baseline level of regulation.
This approach would enable an NES to regulate known, incontrovertible risks nationally, whilst encouraging local authorities to go beyond that level of regulation when (but only when) local circumstances require it.
9.4 Evaluation of Effectiveness of Policy Options
9.4.1 Evaluation of Options (a)-(c)
All of the options (a)-(c) allow for some discretion to be exercised by local authorities. None of the policies require rules to be included in plans, and none insist that consents be required. It is possible that plans could deal with some of the risk by way of standards, and terms or conditions for permitted activities. However, it is more likely that local authorities would interpret the policies as necessitating that plans should require resource consents for relevant activities. Whether they would specify the activities as controlled, restricted discretionary, discretionary or non-complying is more difficult to predict.
Much would depend on what, if any, official guidance accompanied the NPS, and how much effort Transpower and landowners (or representative groups) put into influencing plan change processes.
Although all the above options have the potential to be effective, option (c), being the most prescriptive as to the activities to be managed, may provide the greatest degree of certainty as to its effect.
Option (c) is based on the draft easement agreement that Transpower and landowners have developed for new lines. The draft easement agreement may provide a reasonable basis for determining the minimum protections Transpower requires with regard to existing lines. In negotiating the draft, Transpower has been aware of the need to pay compensation for easements, and accordingly, has needed to make trade-offs between risks to the network and costs of compensation for the restrictions on landowner's activities.
However, there are questions about the appropriateness of option (c). It is sweeping and vague in parts (e.g. the prohibition on planting any vegetation). More importantly, it does not contain the qualifications (such as being allowed to plant vegetation with the written approval of Transpower), or the checks and balances as contained in the model easement agreement. The agreement is a negotiated agreement which spells out the rights and obligations of both parties (landowners and Transpower), while option (c) simply specifies restrictions on the landowner.
9.4.2 Effectiveness of Option (d)
If properly enforced, an NES of the nature outlined would be effective in addressing the three risk activities specified in NZECP 34. Certainly it removes the ability for local authorities to permit risk activities without scrutiny.
However, the NES would not be effective in addressing risks (and potential costs) presented by matters not covered in NZECP 34, and in particular:
- subdivision consents for new lots that propose building platforms66 under transmission lines; and
- discharges to air, and other one off, unusual or unforeseeable activities that arise from time to time, and pose risk to the transmission network.
9.4.3 Evaluation of Effectiveness of Option (e)
Option (e) would give certainty that specific (high risk) activities would require consent but also discretion for local authorities to regulate beyond those "bottom lines" when a case could be made to justify further control.
Option (e) is therefore a potentially more effective option than any of the preceding options. However there could be significant, though variable, cost implications depending on which combination is selected (see section 9.5). There is also the potential for inconsistency to arise between the implementation of the policies and the NES.
9.5 Evaluation of Costs
9.5.1 Costs of Options to Manage Incompatibilities
Private Compliance Costs
Options (a)-(c) set out above have the potential to impose additional compliance cost on landowners, whose land is traversed by pre-1988 lines.
The costs would take the form of lost opportunity costs (in terms of diversification/development options forgone). Submissions received by the Reference Group suggest that this could heighten concern about compensation issues associated with transmission.
How great that cost (and which option is the least costly) would be would depend on:
- Exactly how the policies were translated by individual local authorities (and in particular whether rules were inserted in plans requiring resource consents to be obtained);
- What, if any, rules might already be included in plans (and therefore whether there is any additional cost);
- How any new plan rules would vary from the existing requirements of NZECP 34;
- The circumstances of the case (for example, the size of the property and whether alternative sites are available for the proposed diversification / development within that property); and
- Whether any consent applications that might require compliance with newly imposed rules, were granted.
Because these matters are not known at this time, and are in any event difficult to determine, little can be said about the relative private compliance cost of the options.
Options (a) and (b) could potentially give rise to plan provisions that are more onerous than that promoted by option (c), particularly if the national grid is declared a physical resource of national significance.
Option (c) would have little cost implications for those landowners subject to post 1988 lines since it would result in the same or similar restrictions to those likely to be agreed through individual easement agreements. Additional costs for landowners would be associated with applying for resource consent that they would otherwise not require.
Option (d) should not, in theory at least, produce any significant marginal cost for landowners in terms of lost opportunity cost since it merely involves moving existing restrictions into the RMA framework of control.
In practice, option (d) may impose some additional costs because (i) there would be stronger compliance (that is landowners would be less likely to get away with avoiding the need to comply); and (ii) there could be increased transaction costs associated with gaining resource consents (i.e. cost associated with application fees, professional advice etc).67
Option (e) would obviously impose the same costs on landowners as option (d) plus whatever costs are associated with options (a)-(c).
It seems most likely, however, that option (d) would have the lowest marginal cost for landowners. Option (e) would likely have the next lowest cost implications. These costs may vary depending on whether pre or post 1998 lines are being considered.
A summary evaluation of private compliance costs is set out in Table 4.
Table 4: Summary Evaluation of Marginal Cost on Landowners
| Option |
Owners affected by Pre 1988 lines |
Owners affected by Post 1988 lines |
| (a) General policy |
Potentially moderate/high |
Potentially moderate |
| (b) Specification of effects |
Potentially moderate/high |
Potentially moderate |
| (c) Specification of activities (as per draft model easement agreement) |
Likely moderate |
Likely minimal |
| (d) NES (based on NZECP 34) |
minimal |
minimal |
| (e) NES |
+ (a) |
Likely moderate/high |
Likely moderate |
| + (b) |
Likely moderate/high |
Likely moderate |
| + (c) |
Likely moderate |
Likely minimal |
Public Compliance Costs
At this point there has been no analysis of the provisions in plans that might already give effect (or partial effect) to any of the policies indicated. As indicated above, the Reference Group has based its evaluation on the assumption that activities beyond a certain scale or in certain locations are already regulated in plans. It is equally likely, however, that current thresholds (for activities like earthworks) might not be regarded as adequately giving effect to the suggested policies.
Although further work on this issue may be required, it is likely that most district and some regional plans would need to be changed to give effect to policies options (a) - (c).
Option (d), on the other hand, would not necessitate local authorities changing their district and regional plans. An NES has the advantage of standing alone and not requiring translation through plans. .
In summary, there is likely to be some cost associated with options (a)-(c) for most, if not all local authorities. Option (d), however, would be largely costless from a local authority plan compliance perspective.
On the other hand, all policy options infer that a local authority may need to become involved in controlling a range of activities that they currently do not. Local authorities might regard the control and enforcement of such matters to be central government's responsibility under NZECP 34. Extended functions inevitably means some extra cost and not all costs (particularly those associated with policy development, monitoring and enforcement) can be easily passed on to applicants. In that sense all options might have at least modest cost implications for local authorities.
9.5.2 Benefits of Policy Options to Manage Incompatibilities
Private (Transpower) Transaction Costs
All policy options would reduce the need for Transpower to be involved in making submissions on plans and policy statements. Or at the very least, it would make Transpower's involvement in those processes more certain, and to the extent that it is within the terms of the policy, more effective. It is likely that Transpower's level of involvement in local authority hearings and its perceived need to take plan matters to the Environment Court would be significantly reduced.
Transpower argues for controls over land use that extend more broadly than both NZECP 34 and the model easement agreement and will presumably continue to advocate for such controls in district and regional plan processes. Therefore option (d) offers the least potential benefit from Transpower's perspective whereas options (a), (b) and (c), promoting (potentially) the broadest control, offer the most benefit.
Network Protection and Performance
All policies could reduce the risk that (i) transmission is disrupted (or network maintenance needs increased); and (ii) that people and property are placed at risk from electrical hazards.
Option (d) (bringing components of NZECP 34 within the RMA framework) has particular merit in managing the risk of electrical hazard. Transpower research68 shows a high level of non compliance with that code and having key element of that code within the RMA framework would produce an incidental benefit in terms of ensuring that key NZECP 34 controls are better enforced.
A national database of non compliances shows 1561 cases where the minimum safe distance have not been adhered to (these include, buildings, stockpiles and fences). The data base is not yet complete, but it is estimated that once complete, there will be approximately 5000 recorded instances of non compliance.
It may also be relevant to note that the database shows that since 1990, new non compliances have been occurring at a rate of about 23 cases per year. If the data base is only about one third complete as suggested, the actual rate of continuing non compliance could be as high as 70 cases per year.69
Instances of non compliance are currently prioritised by Transpower and, where necessary, efforts are made to remove/reduce risks. An option that includes option (d) could well avoid future non compliances and greatly reduce both risk and the on-going costs of removing/reducing that risk.
On the other hand, as noted above, options (a), (b) and (c) have the potential to reduce a broader range of activities than those that would be controlled by an NES based on NZECP 34.
Other Benefits
If properly implemented, all policy options could be expected to:
- increase certainty for both landowners and Transpower;
- indicate that Transpower may need to negotiate easements (and pay compensation) for greater levels of protection greater than that outlined in the NPS/district plans; and
- provide a form of defence for landowners who could face common law action by Transpower for actions that give rise to loss (provided the landowner acts consistently with the RMA requirements).
At the same time, landowners would retain the protection provided for by the Electricity Act, such that they are compensated for any restrictions on land use associated with the development of new lines (including upgrades to existing lines that injuriously affect the land).
9.6 Overall Assessment of Options
The Reference Group notes the potential inherent in options (a) - (b) for landowners affected by pre-1988 lines to face restrictions on land use that are more onerous than those negotiated under easement agreements in respect of post-1988 lines. The Reference Group has a level of discomfort about that possibility, particular given existing landowner concerns about compensation issues.
There is a strong case to suggest that the easement agreement-based rule (option (c)) and an NZECP 34-based standard brought into the RMA framework (option (d) would together yield most benefits for least cost since:
- the easement agreement has ostensibly been accepted as a reasonable imposition on landowners and an adequate protection for Transpower; and
- the standards based on NZECP 34 cannot be regarded as "new" costs in the sense that compliance with this code is already mandatory (albeit that it is not always adhered to).70
However, it is also noted that Transpower is concerned that neither NZECP 34, the Trees Regulations or the draft model easement agreement (or the combination of the three) address all the risks that the transmission network is exposed to. Essentially, those existing instruments deal only with risks posed by certain activities likely to be carried out by a landowner within the easement corridor.
As noted earlier in this report, Transpower is also of the view that easement agreements are related to private issues of access to private property and should not be conflated with the separate issue of landowners' environmental responsibilities under the RMA. Federated Farmers, on the other hand, maintains that it is unjust to establish a right to compensation for losses suffered through one regime, and promote, through a different regime, the imposition of identical costs without compensation.
Weighing all those matters, the Reference Group considers that the most appropriate way forward is presented by option (d). That option represents low public and private compliance cost and deals with the majority of risks likely to arise. Admittedly there may, from time to time, be activities that are able to establish in locations and in ways that present some risk to the transmission network and that may not be subject to resource consent processes that allow the potential effect on the transmission network to be properly scrutinised. However, the Reference Group considers that risk is minimal. Further, by majority, it considers that it would be inappropriate to mandate through an NPS, without compensation to affected landowners, restrictions that if imposed through private agreements (as is required by separate statute in respect of post 1988 lines) would result in compensation.
With that in mind, the Reference Group is of the opinion that that option (d) offers the most efficient policy option having regard to appropriateness and the relative benefits and costs. Both Transpower and Federated Farmers hold, for different reasons, contrary views. The Reference Group accepts that the option represents a compromise position and considers that a reasonable compromise for the government to make.
9.7 Policy: Depicting Transmission Lines on Planning Maps
Showing transmission lines on planning maps contributes to the objective of protecting the transmission lines from the effects of other activities because it would ensure applicants and decision-makers are aware of the presence of lines when making and determining applications for activities that might affect those lines.
Two options would be possible depending on the degree of direction that is regarded as appropriate. These are as follows.
(a) District [and regional plans] should recognise [and record in map form] the presence of existing transmission lines, whether or not such lines are designated.
or
(b) As a matter of good practice, local authorities should consider showing the location of existing transmission lines (whether or not such lines are designated) on relevant planning maps.
9.8 Evaluation of Appropriateness
Option (a) is clearly more directive than option (b). Option (b) is worded more as guidance on what might be considered good practice. There may be some doubt about the appropriateness of including good practice guidance in an NPS. Certainly, option (a) provides greater assurance of compliance and might therefore be regarded as more effective.
9.8.1 Costs of a Depicting Lines Policy
Public Compliance Cost
Transpower holds GIS data on the location of its transmission lines. Transpower has suggested that this could be provided free of charge to local authorities. The cost to local authorities of overlaying that data file onto existing planning maps will depend on the format in which existing planning maps are currently held. No research has yet been carried out on that question. However, if planning maps are in digitised format, the cost of adding a further layer of data is likely to be minimal.71
The most significant cost would arise if the NPS required local authorities to make a formal change to district plans, using the First Schedule process,72 to add the transmission line data to existing maps. The cost of changing plans has been discussed previously (see section 8.4). However, this cost could be avoided if the NPS stated that local authorities need not use the First Schedule process. In addition, there would be a cost associated with reprinting planning maps (although much of that cost could be passed on to plan users).
An alternative to allowing local authorities to change planning maps without further formality would be for the NPS to provide for a transition that allows the suggested policy to be "given effect to" during the course of anticipated plan reviews.
Private Compliance Costs
The policy only requires presentation of information and therefore there is nothing additional for an applicant or potential applicant to comply with.
However, to be effective, the depiction of transmission lines on planning maps will need to alert applicants and/or local authorities to issues that might not otherwise have been recognised. To the extent that this results in decisions or conditions that would not otherwise have been made/imposed there may be some cost for those persons proposing to undertake activities under and around existing lines.
9.8.2 Benefits of a Depicting Lines Policy
Benefits to the Safety and Reliability of the Transmission Network
The principal benefits of the policy have been addressed above. The alerting of applicants and local authorities to the presence of transmission lines can (a) avert risk from electrical hazard; (b) avoid the need for costly remedial action (by Transpower and landowners) to reduce risk that has been created; (c) avoid potential risks to the safety and reliability of the transmission network; and (d) reduce any risk of local authority liability for the creation of risks outlined.
The Reference Group believes that the moderate and manageable costs of the policy are outweighed by the benefits and considers the policy efficient in those terms.
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