Underground Power Cables & Fibre Optic Cables

Before you undertake any excavations please check with Network Tasman about the location of underground cables

Plans of Network Tasman recorded underground power cables are available from:

Scott Robinson
Network Tasman Limited
PO Box 3005, Richmond
Nelson 7050

Phone:  0800 508 098 or 03 989 3621

BEWARE: Unrecorded underground service main cables may be sited in the area you wish to excavate.

Before you undertake any excavations please contact a cable location service for an on-site cable check:

  • DELTA Utility Services | Ph: 03 543 8071
  • Power Trace | Ph:  03 545 8300
  • Marlborough Lines | Ph:  03 577 7007  (Blenheim/Wairau Valley)

Overhead power lines

Excavations near overhead distribution lines can seriously threaten the stability of nearby power poles.

The owner or operator of any crane, loader, excavator, drilling or pile driving equipment or similar plant should not use the equipment any closer than four metres from the conductors (wires) of any overhead distribution lines without first contacting Network Tasman. Call us on 0800 508 098 or 03 989 3600

You must comply with Section 5 of the New Zealand Electrical Code of Practice for Electrical Safety Distances.

In some cases e.g. major excavations which may affect the ground stability of a structure foundation (and must be accompanied by appropriate retaining walls), you will need to operate equipment at a great distance from overhead distribution lines or power poles.

On-site observer

The primary objective of Network Tasman’s standover service is to ensure the integrity of our network and the correct reinstatement of our asset.  Our observer is responsible for encouraging safe practices, and reporting to Network Tasman on the contractor’s use of safe practices.

The service is not intended as a substitute for using a cable location service. 

The service does not in anyway relieve the contractor from any of his/her responsibilities under the Health and Safety in Employment Act.

Network Tasman encourages contractors to request an observer whenever excavating within a metre of a high voltage cable.  The service is not intended to be an on-call response to a third party demand.  It is a discretionary service that may be provided by Network Tasman based on information given by the contractor at the time the request is made.

When you telephone to request a standover you will be required to provide the following information:

  • The name of the service provider that located the high voltage cable on your behalf
  • The reason for and expected duration of the excavations
  • The physical site conditions and layout
  • Your intentions with respect to our cable and your contingency plan if the cable proximity to your work is unacceptable to either Network Tasman or the third party client

If the cable is to be exposed we will need to know the following:

  • The precautions you have planned to minimise risk i.e. if it will be fenced or covered
  • The precautions you have planned to minimise asset damage e.g. cable supports
  • The arrangements you have made for correct reinstatement of the cable
  • The length of time you intend to leave the cable exposed

Underground power services present a very serious and potentially fatal hazard if damaged.  As a consequence, contractors working near underground cables have a responsibility under the Health and Safety in Employment Act to identify and manage these hazards.  If a cable is present in an area you intend to excavate, we recommend that you:

  • make use of a professional location service to locate the cable
  • follow recommendations made by the cable location contractor with regard to excavations near the cable
  • request a standover if excavating within one metre of a high voltage cable
  • pot hole until the cable is found before commencing machine excavations.

To request a standover please call Network Tasman Limited on 0800 508 100.  Your must request the service at lease 48 hours in advance of when it is needed.  (Concessions may be made in an emergency i.e. broken water main). Please note:  the observer’s time is not chargeable. 

Important facts 

  • All work near high voltage power lines is subject to The New Zealand Electrical Code of Practice 34 
  • You must get Network Tasman approval before you alter the ground level under an overhead line or above underground cables 
  • Excavation must not be undertaken close to poles if this could threaten the stability of the structure
  • All buildings under or near distribution lines are subject to legal conditions
  • Please seek advice from Network Tasman before proceeding with excavation work
  • If you cause damage to our network you will be liable for the cost of the repairs. You may also be liable for any lost revenue we suffer and for  any losses or damage caused to parties connected to our system.
  • It is most important to contact a cable location service for an on-site check for underground cables.  Cable location services are chargeable
  • Network Tasman is not liable for the work or any actions of the cable location service 

Additional resources

The Worksafe NZ document ‘Guide for Safety with Underground Services’ is also an important resource.

Please click here to download a Network Tasman brochure with information about what you need to be aware of when you are planning or undertaking and undergrounding work.