Portal FAQs
Corridor Land Use Management FAQs
What is Corridor Land Use Management?
Corridor Land Use Management is the work Transpower does to manage and protect National Grid asssets from inappropriate land use development and activities undertaken by landowners/developers via a Resource Management Act (RMA) process.
Under the RMA, the National Grid is recognised as nationally significant infrastructure that must be sustainably managed, and any reverse sensitivity effects on that infrastructure must be avoided. Activities under the RMA must also be managed to ensure that the operation, maintenance, upgrading, and development of the National Grid is not compromised. Changes in land use and development have the potential for adverse effects on Transpower’s assets and the use of its corridors. Likewise, Transpower’s existing assets can adversely affect the land use and development.
What are the main areas of risk associated with building and development near the National Grid?
Inappropriate land use and development can pose a significant risk to the operation of the National Grid, creating electrical and physical hazards which result in line faults or power outages. This has flow on effects for the security of the transmission network, ultimately affecting the operation of the overall electricity system. This can be inconvenient and expensive not only to Transpower but to consumers.
The main areas of risk arising from incompatible land use, development and activities near the transmission network are in relation to:
- the health, safety and well-being of persons and property;
- the operation of the transmission network;
- access and maintenance of the assets; and
Section 2 of Transpower’s Development Guide (In the Pātai Resources Section) provides a good overview (including images) of some of the key issues arising from incompatible development and activities.
What is a Sensitive Activity or Building?
A Sensitive Building includes: New Dwelling/s (including minor dwellings, garage conversions, papakāinga, visitor accommodation, boarding houses, integrated residential development, retirement villages, supported residential care); School / educational facilities; Hospitals, healthcare facilities or care centres.
What is the National Grid Yard?
Within the National Grid Subdivision Corridor is a narrower National Grid Yard. The National Grid Yard is the area beneath, and immediately next to, National Grid lines (including their support structures).
It is a 12m setback either side of the centreline of a National Grid line and 12m in any direction from the outer edge of a National Grid line structure. This is reduced to a 10m setback where the line is a single pole line, although the distances from the structures remain the same.
What can I do in the National Grid Yard?
Transpower seeks to keep the National Grid Yard (NGY) free of buildings and structures and to manage land use and activities that could pose a risk to your safety or to the safe and efficient operation of the National Grid. What can (and can’t) be established within the NGY depends on where your site is located. Existing activities within the NGY can continue as is.
In any location (urban or rural), Transpower will not support any new or extended sensitive activities within the NGY. In many situations it is possible to design around National Grid lines and land within the NGY can be utilised for other activities.
If you wish to establish a new building or structure, subdivide, or substantially change land uses within the National Grid Corridor or NGY, please contact Transpower to discuss your proposal as soon as possible.
What is a Subdivision Corridor?
The National Grid Subdivision Corridor is the area where Transpower needs to be involved in the design and layout of a subdivision (and its subsequent land use). It is usually the area up to 39m either side of the centreline of a transmission line. This is the general extent of the area where the conductors (wires) are physically present - as the lines can swing out this far in high wind conditions. The size of the corridor differs depending on the voltage and type of support structure.
In the Auckland Unitary Plan, the National Grid Subdivision Corridor has varying widths depending on the maximum “blowout”, or swing, of the conductors (“wires”) on each individual line span (the distance between the support towers or poles).
What can I do in the National Grid Subdivision Corridor?
Subdivision is an opportunity to design new development in a manner that takes the lines into account – including ensuring allotments are of a size that can be safely developed. Many activities, including residential buildings, can occur within the Subdivision Corridor, provided they are set back outside the National Grid Yard and access to towers and poles is maintained.
What is NZECP34:2001?
The New Zealand Electrical Code of Practice for Electrical Safe Distances (NZECP 34: 2001) (NZECP) is an electrical code of practice and regulation under the Electricity Act 1992. NZECP sets minimum safe separation distances for buildings/structures, earthworks, mobile plant and people from transmission lines and support structures. These minimum safe distances have been set primarily to protect persons, property, vehicles and mobile plant from harm or damage from electrical hazards.
Compliance with its provisions is mandatory (Regulation 93 of the Electricity Regulations 1997).
It is important to note that compliance with NZECP does not mean there are no adverse effects on Transpower’s assets. NZECP does not consider the operational, maintenance (access) and upgrading requirements of the National Grid. Reverse sensitivity and amenity effects are also not considered. These matters are covered in Transpower’s Corridor Management approach (e.g. National Grid Yard 12m setback). This is why compliance with NZECP is in addition to Transpower's National Grid Yard and Corridor setbacks.
What is the National Policy Statement on Electricity Transmission 2008 (NPSET)?
The NPSET is a National Policy Statement providing direction for local authorities on how to recognise and provide for the national significance of the National Grid in Resource Management Act 1991 planning documents and decision making. These documents include regional policy statements, regional plans and district plans.
The Objective of the NPSET is:
“To recognise the national significance of the electricity transmission network by facilitating the operation, maintenance and upgrade of the existing transmission network and the establishment of new transmission resources to meet the needs of present and future generations, while:
- Managing the adverse environmental effects of the network; and
- Managing the adverse effects of other activities on the network.”
What is the difference between the setbacks in NZECP and the National Grid Yard setback?
The safe separation distances under NZECP address safety issues only, whereas the National Grid Yard (in line with Policy 11 of the National Policy Statement on Electricity Transmission 2008 (NPSET)) is a trigger to consider the operation, maintenance and upgrading requirements of the National Grid, as well as reverse sensitivity and amenity issues. Although separate requirements, the National Grid Yard and NZECP setbacks can overlap and any development must comply with both.
I am looking to purchase a property that has transmission lines on/near it. What can I do on that site?
For pre-purchase enquires, please contact the Council in the first instance. Although National Grid transmission lines are Transpower assets, the rules applying to them are Council rules within their District Plans. The Council’s duty planner will be able to advise what National Grid rules within their District Plan apply to your site and proposal, including whether or not resource consent is, or may be, required.
I have a received a LIM from the Council and it says the site is subject to a National Grid Overlay (or it has transmission lines present) What can I do on that site?
Please contact the Council in the first instance and get them to explain the overlay and what may be required. Although National Grid transmission lines are Transpower assets, the rules applying to them are Council rules within their District Plans. The Council’s duty planner will be able to advise what National Grid rules in their Distrcit Plan apply to your site and proposal, including whether or not resource consent is, or may be, required.
What are the Electricity (Hazards from Trees) Regulations 2003
The Electricity (Hazards from Trees) Regulations 2003 (referred to as Tree Regulations) are designed to protect the security of supply of electricity, and the safety of the public, from hazards from trees. It prescribes distances from electrical conductors within which trees must not encroach, setting rules about who has responsibility for cutting or trimming trees that encroach on electrical conductors, and assigning liability if those rules are breached. Any trees growing near high voltage transmission lines must be managed to comply with these regulations.
Where can I find further information?
You can find further information here: