Aerial Surveys

Unison Annual Aerial Survey To Commence Mid-February

From mid-February, Unison Networks will commence its annual aerial survey of its power lines in Hawke’s Bay. 

The annual survey will be conducted via helicopter and, depending on weather conditions, is expected to be completed by the end of February. 

Unison actively works to minimise any potential power outages caused by equipment faults or vegetation issues. The annual survey is an efficient means of inspecting overhead line assets and provides vital information on their condition, enabling preventative maintenance and replacement to ultimately improve network reliability. 

All practical measures will be used to ensure livestock and domestic animals are not disturbed by the aerial survey. If sensitive livestock such as horses are observed from the air, Unison will actively attempt to bypass those areas. 

Unison’s schedule for when it will conduct the surveys varies and is dependent on weather and other circumstances. Therefore, Unison is unable to provide exact dates and times for when it will be carrying out the survey in your area.

To view the areas that will be affected by our 2017 aerial surveys, see map below.


Why does Unison carry out aerial surveys?
We own and operate over 9000km of power lines across the Napier, Hastings, Rotorua and Taupo areas.

In order to ensure our overhead electricity network is in a safe condition, we use a helicopter to carry out routine assessments from above, to get a closer look at the equipment on the top of our power poles (such as conductors, insulators and cross-arms), and check for any potential hazards.

Aerial surveys are a cost effective method of inspecting long stretches of power lines, often located in areas that are difficult to access from the ground.

How often does Unison carry out aerial surveys?
Our aerial surveys are carried out annually, typically between April and July. However, in situations such as storm events, we also carry out helicopter patrols to locate faults on our network, when ground access can be difficult.

What time of day are the surveys carried out?
Our surveys are generally carried out on working days, during day light hours only, and only when weather permits – we do not carry out surveys when there are high winds, low cloud or fog, or heavy rain.

How do I find out when Unison is carrying out aerial surveys?
We use local radio stations and newspapers to advertise our aerial surveys in each region we operate in.

We also use our Social Media channels to post up to date information about our surveys – find us on Facebook and Twitter to stay updated:;

What steps does Unison take to ensure animals aren’t impacted by aerial surveys?
Our asset inspectors treat animal safety very seriously and take all reasonable steps to ensure animals are not affected by our aerial surveys.

Our inspectors stay in constant communication during our surveys and report on everything they can see including livestock, other aircraft, loose roofing iron and stock being rounded up into a paddock.

The team will immediately retreat as soon as any animals or other hazards are spotted in the areas they are flying in.

What should I do if I have questions or concerns about aerial surveys?
Give us a call on 0800 2 UNISON for any further information about our aerial surveys or to express any concerns.