Finding underground pipes & cables
We offer a free service to help you to locate underground cables, pipes and ducts before you begin digging or excavating.
If power or fibre cables are struck and damaged, it can knock out important electrical or communications supplies. It could also result in an electric shock, explosion or death.
Step 1: Obtain reference maps
Visit www.beforeudig.co.nz or call 0800 248 344 to request plans at least two working days before you begin work. They will then email you the free reference maps that indicate the approximate location of underground cables.
Please note that these reference maps are valid for 28 days from the date of issue; new maps have to be requested after 28 days.
The accuracy of maps cannot always be guaranteed as road realignment, reconstruction, alterations to ground cover and property boundaries can all affect accuracy. This means that you will have to confirm the location of our cables within your work site before you begin any work.
Step 2: Locate assets in relation to your worksite
If your worksite is indicated within 10 metres of our cables you must carry out a cable/pipe location to identify the approximate location of the cables. We can come to site and locate the cables for you, marking them with dazzle and advising approximate depth.
You'll need to apply for a cable location service, which you can do at the bottom of this page. Allow 2 working days and the service is free. If you need to locate underground cables and pipes urgently or on a weekend or public holiday please call us on 0800 10 40 40.
Please note your responsibilities under the Health and Safety at Work Act 2015, whereby you must establish the location of underground services before commencing excavation. You must also locate the services by ‘potholing’ using recognised techniques to expose cables and to continue working safely.
Step 3: Confirm the physical location of cables and pipes by pot-holing
Potholing requires using recognised hand digging and/or hydrovacing techniques to expose the cables. and pipes. These techniques are less likely to result in a strike on the services that causes serious damage to cables and pipes. For your own safety you must pothole with caution. If you damage a cable or pipe please report this immediately to Northpower Faults by calling 0800 10 40 40.
Remember to check for other services coming off a main such as water and private service cables and pipes.
Step 4: Use a designated Safety Observer
All works within 2 metres of high voltage network electrical cables, or any Northpower critical electricity or fibre lines require a Northpower stand over at the cost of the contractor.
Step 5: Continue working safely
- If you discover marker tape or protective covering for unmarked cables, you must pothole to expose the cable.
- Always assume that cables are live until confirmed otherwise by a Northpower representative. If you want to lift, lower, sift or remove any cable or expose a cable so that more than one meter is supported, specialist involvement is required by Northpower’s Engineering team.
- Backfill should be a recommended stone free soil or approved thermal backfill.
- Don’t forget to put mechanical protection and warning tape back when reinstating.
Organise a cable location service
Please allow a minimum of 2 working days to process your request. If you need to locate underground cables and pipes urgently or on a weekend or public holiday please call us on 0800 10 40 40.
For further advice, please contact us
Cable location request applicationFrequently asked questions about digging & excavating
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Who's responsible for locating cables and pipes?
It's your legal responsibility to establish the location of cables and pipes before you dig. Repairs can be expensive and any costs incurred will be charged for.
Under Worksafe legislation, we can prevent any work continuing that is likely to cause damage to our network or serious harm to a person.
Further useful information can be found on the Worksafe New Zealand website.
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How deep are cables and pipes generally laid?
Our cables and pipes are laid at different depths in the ground, usually varying from 600mm to over 1200mm. Reference maps are a good indicator of cable and pipe locations, but because of the changing ground and marker movement, we can’t guarantee the exact depth or location of any cable.
Please refer to Worksafe New Zealand’s Guide for Safety with Underground Services for full procedure when excavating around cables. Hand excavation should always be the first step when locating underground cables.
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Can I use a mechanical digger to excavate near cables?
For safety reasons, mechanical diggers can't be used within 450mm of a cable.
If you're more than 450mm from a cable, it's a requirement to hand dig first before using mechanical diggers. Hand digging is less likely to cause serious damage to cables and pipes and helps protect your safety.
Remember to also look out for services coming off a main.
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What do power cables look like?
While power cables are sometimes found inside ducts, they can also be buried with timber, concrete or plastic slabs above for protection.
They may also have orange plastic danger tape indicating cables below.
Cables can shift over time so may not always be visible.
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Can I move an electrical cable?
It's important that electrical cables aren't moved without Northpower approval. Some cables rely on paper for insulation and any kinking can cause electrical breakdown and an explosion risk.
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What should I do if I accidentally hit a cable or pipe?
For safety reasons please cease work and contact us immediately. After contacting us, please make the site is safe and prevent anyone else from accessing the damaged cable.
Need more information?
For more information on working safety around our network, please download our safety booklet.
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