Rotorua geothermal activity: Mud pot neighbour may consider moving if mud pot gets bigger

A mother living near an up to 30-metre-wide geothermal “mud pot” that burst open early last month says she may consider moving her family out if the hole keeps getting bigger.

She has criticised Rotorua Lakes Council for a lack of ongoing communication after learning from the Rotorua Daily Post that the hole expanded in late August.

The council says it has been speaking to residents available when staff are inspecting the site and it would “proactively contact nearby residents” if it learned of a change to risk levels. The new growth had not increased its concern for people’s safety.

Genna Emery is concerned about the geothermal feature 25m from her house opening up anymore. Photo / Andrew Warner

The mud pot burst into life again on August 11 at a property off Meade St in Whakarewarewa.

The activity was in the same area as a similar eruption in 2019 that forced the evacuation of a neighbouring property.

Genna Emery’s home of about three years is about 25m from the mud pot and said the last three weeks had been “scary” with her house shaking at all hours.

However, in the last few days, she noticed the steam had died down, barely any mud was coming up, and the house had stopped shaking.

She said the smell was “strong”, especially on rainy days, and about a week ago a large amount of potent steam went through her property.

She said every time the mud would “plop”, the house shook, which started when the mud pot reactivated last month.

The geothermal feature at the end of Meade St, pictured this week. Photo / Andrew Warner

“It was all during the day and the night, and my bed would shake.

“Every time that happened, I thought, ‘Oh no, is that an earthquake?’”

Emery was not aware that the feature had increased in size 12 days ago until told by the Rotorua Daily Post.

“That’s not what I want to hear,” she said.

The geothermal feature erupted last month. Photo / Ben Fraser

Emery said she was “concerned” and considering leaving the area to keep herself and her three children safe if it got any bigger.

“It opened up in 2019, four years ago, what happens if it happens again, but bigger?

In her view, the feature increasing in size was information she should have been told about and “the council should be communicating with us”.

She said she had contacted the council about the shaking, but it had not contacted her in the first instance for anything else.

“No matter what … every time they [council] went to go check it, they should have given us [residents] an update. That’s how I feel.”

She said staff could leave a contact card or note for residents who were not home when they were in the area.

GNS Science volcanologist Brad Scott told the Rotorua Daily Post the mud pot was about 2-3 metres wide and 25-30 metres long after a “small amount of collapse” at its south end on August 27.

“About 3 metres has fallen into the depression.”

Scott said the reactivated geothermal feature and its hazards were still “well within” the fenced-off property’s boundaries.

Scott said the council would let people know if they needed to evacuate due to safety concerns.

The level of activity was variable and expected to continue for weeks or months, but it was showing a decline with time, he said.

“Past activity has been stronger, especially with more heat present beyond the active mud pot,” he said.

“That heat caused trees to die off.”

He said there was a “minor indication of that” now, but not as strong as in 2019 or the activation several years earlier.

Scott said a gas odour near geothermal features was common.

The geothermal feature pictured when it reactivated last month. Photo / Ben Fraser

“The physical processes that drive mud pot activity include very small ‘steam explosions’.

He said a with all explosions, a “thud or thump” would be generated, which could be felt within 20-30m of the mud pot.

Council community and district development group manager Jean-Paul Gaston said on Wednesday that geothermal surface features “commonly change to some degree over time”, especially during periods of activity.

“Changes to the mud pot, most of which is on an unoccupied private section with some on council reserve land, have not increased the level of concern with regards to people’s safety at this point in time.”

He said the council would “proactively contact nearby residents if we become aware of changes in the level of risk to them or their properties”.

While geothermal activity had reduced this week, the area was still cordoned off and the council would continue to monitor it to “help ensure public safety”.

The geothermal feature from the air after it burst into life in 2019. Photo / NZME

Gaston said that throughout the last month, staff had “spoken to residents available while we were in the area inspecting the site and we last spoke to available residents on 30 August”.

He encouraged people to call the council at any time if they had any concerns.

On Monday, a council spokesperson said staff periodically checked the ground heat and gas emissions at the site as a precaution.

“There have been no recent reports to council from residents about the activity that would currently be cause for additional concern.”

“We remind everyone to avoid that area if possible.”

Cira Olivier is a social issues and breaking news reporter for NZME Bay of Plenty. She has been a journalist since 2019.