Rocky picture show at the Mount

By ROSALEEN MacBRAYNE

A loud explosion rocked Mauao, the landmark hill at Mt Maunganui yesterday, momentarily lighting up the grey sky. Then a flurry of boulders began thudding down the eastern face amid clouds of dust.

The big bang was carefully orchestrated by a team of experts to remove dangerously unstable rock near the summit of the famous Bay of Plenty landmark.

Even a minor earthquake could have triggered the collapse of 500 tonnes of rhyolite in three columns.

Up to 20kg of explosive charges were placed strategically so the 85 cu m of rock - about the length of a car and trailer - would be blown into pieces.

A team of abseiling geotechnical engineers drilled holes and packed each one with a 200mm long explosives stick.

The charges were linked by wires and detonated from a safe distance near the Mount summit, using a tiny control box.

Although an hour behind schedule, the manoeuvre went off with military precision.

The greatest impact was from a hefty boulder which crashed into one of the 47 shipping containers protecting the camping ground, hot pools and surf club below.

In all, five large fragments tumbled through thick vegetation nearly 230m down into the evacuated camp at the base of the Mount, but most of the debris came to rest harmlessly on the grassy slope above.

The damage was minimal, engineering geologist Neil McHugh said later. The ding in the container was a "one day panelbeating job".

When the blast came, cheers rose from the crowd of about 500 watching from behind barricades manned by security guards. Some people had waited for hours in the biting cold for the fireworks, a few bringing deck chairs and picnics.

But it was a sad moment for others.

"It brought tears to my eyes," said Peri Kohu, there to represent the runanga Ngai Tamarawaho. He said his hapu were the last residents on Mauao in 1750 and the mountain remained sacred to them.

The Tauranga District Council should have left the Mount alone, Mr Kohu said.

"They tell us it was a safety issue but Mauao has been there since time immemorial. Let the mountain speak and let the rock come down by itself if that is what is going to happen."

Yesterday's blasts and the January fire which destabilised the brittle rock were both "man-made" and destructive, he said.

Tauranga iwi Ngaiterangi, Ngati Ranginui and Ngati Pukenga had been told about the detonation after plans were already in place and Mr Kohu said they would now be meeting the council to insist on protocols for the future.

The hot pools are expected to re-open tomorrow and the camp on Tuesday, after the shipping containers have been removed.

People will once again be able to walk up and around Mauao from early next week and the mountain's 550 resident sheep will be returned to their familiar pastures.