Northwest Iowa Power Cooperative had gone four years without experiencing copper theft, but that changed with a major incident in late August.

Thieves stole about 300 pounds of copper, causing an estimated $250,000 in damage at four of the generation and transmission co-op's substations serving Western Iowa Power Cooperative as well as one high-voltage transmission substation. While two substations had extensive fire damage, all five sites are back online.

The stolen copper is worth about $980 based on current market prices, said Angela Catton, manager of member relations and development at Le Mars-based NIPCO, the power provider for Denison-based Western Iowa Power Co-op.

“We've had these one-off copper thefts before, but this was the worst," she said. “It's a reminder that this kind of criminal activity still occurs."

Monona County sheriff's deputies got information about possible suspects the day after the incident, executed a search warrant and located the stolen copper.

Craig Keller, 40, and Whitney Reynek, 30, were arrested and charged with first-degree theft, first-degree criminal mischief, third-degree burglary and possession of drug paraphernalia, according to local news reports.

During the afternoon and evening of Aug. 21, alarms notified NIPCO control center operators, indicating failures at the stations. Authorities also received 911 calls of electrical arcing and fires at two of the sites.

“The fire burned so hot that it melted the concrete. The concrete became glass," said Catton.

The damaged substations were located within a 20-mile radius. At each station, the thieves cut through the gates or gained access by cutting a hole in the chain-link fence surrounding the site and stripped copper grounding wire attached to the electric components.

Crews had to de-energize the most heavily damaged substations for several days to assess and repair the damage. About 1,000 WIPCO members lost power for one to four hours, but the system's redundancy limited the length of the outages, Catton said.

“Fortunately, NIPCO's transmission system is looped, so we were able to re-route power through other substations before shutting off the affected subs during the event and in subsequent days as NIPCO crews performed repairs," she said.

Copper theft has ticked upward in recent months as inflation has pushed up prices for the metal. According to mining.com, copper jumped 4.2% for December delivery and is $4.50 per pound.

“Copper theft was really kind of the hot topic for a long time, but it has been pushed down on our list of priority communications," said Catton. “This was a good tap on the shoulder for us to make sure that we are still communicating to our members that this crime still exists."