Whakatāne mayor Tony Bonne says he was unaware of the stress on the stopbank in Edgecumbe, despite locals saying there was a major problem two hours before it burst.

The Rangitāiki River breached the stopbank early last Thursday morning, resulting in widespread flooding and evacuations in the Bay of Plenty town of about 1600 residents.

Locals told RNZ they were angry they were not warned earlier that the stopbank could breach.

The district's mayor told Checkpoint with John Campbell that emergency services, regional council and civil defence personnel were at the stopbank from 5am.

He said he was informed just after 8am that people needed to evacuate and by that time the bank had breached.

"There were some concerns which maybe hadn't been passed onto me as strongly as they could be. I was unaware of the stress of the wall at Edgecumbe and of course I got the phone call at 8.15 to say it's all on, it's gone to custard."

He said he wished he had known sooner so that residents could have saved more of their property.

"What really is of concern to me ... We had our public meeting [and] a Fire Service volunteer got up and he was saying that local knowledge - they had phoned through about 6.30 saying there was a major problem here. Somehow that message hasn't got through."

The Bay of Regional Council has set up an independent inquiry into the circumstances that led to the flooding.