A power company is offering a $10,000 reward to catch those responsible for the theft of valuable copper, causing thousands of dollars worth of damage at Tauranga's main power substation.
Powerco's Waihi Rd facility was targeted by thieves on Monday or Tuesday. Between 20 to 30m of copper cable was stolen.
Powerco network operations manager Phil Marsh told the Bay of Plenty Times the copper was being used as a main earth connection for the electricity system.
He said the actions of the "selfish idiots" had placed lives at risk.
"These thieves have placed the safety of the network at risk to make few hundred dollars from scrap copper.
"Electricity networks require effective earthing to operate safely and reliably and these selfish idiots have put the network and potentially customers at risk," he said.
The company has offered to pay a reward equivalent to any reparation order up to a maximum of $10,000 for information that led to the arrest, conviction and a subsequent reparation order for the theft.
Mr Marsh estimated the costs of the theft to be between $2000 and $3000.
Contractors spent about four hours replacing all main earth connections. Mr Marsh said they also had to conduct emergency switching in "many different parts of the electricity system" to ensure a safe and secure power supply.
The facility was forced into an emergency shutdown but was back up and running and "fully operational" within six hours.
Powerco was able to avoid cutting power to any customers by switching the load to other sub-stations.
Mr Marsh said Powerco would be reviewing security at the site following the theft, which was reported to police.
"Copper theft is and ... has always been a problem but this theft is new and [reached] worrying heights.
"Main substations are very hazardous environments for anyone who is not electrically aware and the senseless and mindless act of removing safety earths makes me think those individuals are either very stupid or are unaware of the danger they have placed themselves and others in. If we can reduce the chances of it occurring again then great, and all the better."
Tauranga scrap metal dealers said copper was a valuable commodity that could easily be "flogged off" for cash.
David Decke, manager of Metal Man Recyclers, said copper could be sold for anywhere between $3.50 and $6 per kilogram, depending on the quality of the copper.
"Copper gets the best price of all the metals. I'm not surprised to hear [of the theft], people will do anything - hot water cylinders and pipes, and cash it in for coin."
Powerco is New Zealand's second largest electricity and gas distribution utility with around 400,000 consumers connected to its networks.
Anyone with information about the copper theft has been asked to contact Tauranga police on 577 4300 or Powerco on 0800 769 372.