Last week, Datagrid announced it had gained consent from the region’s councils for a giant 78,000sqm data centre in Makarewa – about 15 minutes north of Invercargill.

The AI factory is set to become the second largest user of electricity in the country behind Tiwai Point aluminum smelter, and Campbell said the cable would give his city the fastest internet in the country.

In response to a Facebook question about environmental impact from the installation going through Ōreti Beach, Campbell said there would be “none at all”.

But that view appeared to be at odds with independent commissioner for Environment Southland Hugh Leersnyder, who raised a number of environmental impacts.

Mayor Campbell stood by his comment, saying the report did not point out any significant impact on the beach.

“Well if I put a spade in my garden, I’m probably halving a worm in two. There’s no such thing as any kind of development that doesn’t have any kind of impact.

“The question is whether the impact is significant, and obviously it was judged not to be, because the consent was issued.”

Commissioner Leersnyder wrote in his resource consent decision report that key adverse effects of trenching included impact on cultural and spiritual values, potential discovery of a cultural artefact and disturbance of toheroa – a shellfish.

Leersnyder highlighted a risk of disturbance to marine mammals during underwater cable placement, especially whales and dolphins because of sound and vibration.

“The application notes that human-induced underwater noise may cause behavioural disturbance and physiological injury. Any noise effects are expected to be very localised and short-lived.”

The seabed would be disturbed, and benthic flora and fauna could be damaged or smothered, he wrote in the consent document.

Mana whenua representatives would be on hand to relocate any toheroa unearthed at the beach and Datagrid would notify local iwi in advance about digging for the shellfish along the planned cable route, the document noted.

Work would be suspended if marine mammals were within 500 metres during underwater cable laying, and equipment with emission levels of 210dB would be started gradually.

Datagrid would also attempt to avoid sensitive underwater habitats identified during planning and surveying.

The company said it had “maintained open lines of communication with the four Papatipu Rūnaka o Murihiku over many years”, the resource consent decision document showed.

Campbell said Datagrid intended to start earthworks in July.

LDR is local body journalism co-funded by RNZ and NZ On Air.