Taupo's mayor says the drowning of a young woman swept away on Waikato River yesterday when floodgates opened is a tragedy.
But he has stopped short of calling for the Aratiatia Dam tourist attraction to be permanently closed. A safety review is being carried out.
A young woman, believed to be in her 20s, died after she and several friends were swept down the river by rapids that surged when the dam opened about midday.
The swimmers were not visible from the road bridge, where many people gather to watch the water being released, but people at the two downstream viewing platforms saw the group and several made emergency calls to police, Taupo Sergeant Shane McNally said.
"If anyone has any cellphone footage, we're keen to look at that."
He said he understood a group of seven young men and women had been visiting Taupo for the weekend. They had met at the Flochella music festival on Lake Taupo the day before and then decided to stop at the dam for a swim the next day. Some of them had swum there in the past.
He said despite the four water releases a day in summer and warning signs, some people still swam in the pools that were left behind after the rapids had stopped flowing.
"But when the sirens sound, you get out," he said. "It's unknown why they didn't."