What type of surveying will be done?
From the beginning of November, (we used) the latest airborne electromagnetic technology (AEM) to understand more about one of our critical groundwater resources.

What is involved in AEM surveying
AEM surveying involves flying over the land with a loop system suspended from beneath a helicopter. Transmitters on the loop send electromagnetic signals underground, and sensors measure the behaviour of the returning signals. Similar to radar, this method allows us to ‘see’ what’s under the ground by looking at and interpreting, the way the signals return. 

When will the helicopter be flying the AEM surveying?
The survey occurred in November - December, 2022. Preferred conditions for the surveying include low wind, little cloud, and no heavy rain. 

Is AEM safe?
AEM is a safe and effective measurement tool that is used around the world. You may see the helicopter flying overhead but you will not notice any impact from the electromagnetic signals. Airborne SkyTEM is flown at high speed so there is limited exposure to the magnetic field generated from the equipment. The exposure is safer than watching a LCD or plasma TV or blow-drying your hair. 

What about my animals?
The technology is safe to use above animals. Experience in other farming areas is that stock generally aren’t disturbed much by the technology. In New Zealand the team has observed that horses moved to the other side of the paddock when the system came very near.
 
The timing of the survey is early summer for the best flying conditions but is also seeking to avoid the main lambing and calving seasons in Southland.

What will I see?
During an AEM survey, you may see a low-flying helicopter towing a large loop hanging from a cable. It will fly over the area on the below map and ‘scan’ to about 300 metres deep underground, where we’ve never seen before. We won’t be flying over towns or built-up areas.

How will the helicopter fly the survey?
The helicopter will fly at 80-120 km/hr in parallel lines generally 200 m apart and at a height of approximately 100 m. The measurement instruments are suspended under the helicopter and will be about 30 – 50 m above the ground. The noise from the helicopter has been described as equivalent to a truck going past on a motorway and lasts for around two to four minutes. The helicopter flies up and down in lines, so once it flies over, it will then return approximately 15 minutes later but be at least 200 m further away.

Will the helicopter take aerial images too?
We will not be gathering data or information on anything above ground. While the helicopter will carry a camera, this is only to guide the crew managing the loop, and no photos or video are retained or shared.

What will the information be used for?
The information gathered by the helicopter and loop will take some time to process and analyse. Once available, it will provide a much better picture of the underground water resource and reduce uncertainty to help guide decisions for environmental protection, development, resource consents, water management, and water availability for the local community. It will be available to councils, tangata whenua, and community groups, subject to agreed guidelines.
 
We want to assure you that these flights are not in any way used for compliance monitoring. We only want to know about water.

What if I have more questions or concerns?
Please contact us if you have any questions or concerns about helicopter flights over your place. Let us know if you have an event you’d like us to avoid (eg a stock sale, wedding, hui) and we’ll do our best to plan around it.