GDC looks to put mud volcano data in LIM reports

A109 Light Utility Helicopter flight with mayor Gisborne City from the air in November 2023.

Data about mud volcanoes, which are “almost unique to Gisborne” are likely to be included on LIM (Land Information Memorandum) reports.

Gisborne District Council’s Civil Defence Emergency Management Committee has adopted a report noting it is proposed to add the data to LIM reports for affected dwellings in the Wheatstone Road area, in the vicinity of Knapdale Eco Lodge, in Snowsill Road, and certain properties in the Waimata Valley and between Pouawa and Tolaga Bay.

Council principal scientist Dr Murry Cave told the committee a Gisborne mud volcano in 2018 threw boulders 100 metres.

Mud volcanoes did not present an imminent risk, but a risk in the long term.

A significant earthquake, not necessarily close by, might elevate the risk from mud volcanoes.

But the mud volcano might not erupt as it took time for the fluid to reach the surface.

There could be no warning unless there was “precursor movement”, but it would be “pretty obvious what happening”.

People would self-evacuate as during Cyclone Gabrielle.

Any volcanic event was likely to happen during or after a significant earthquake so Civil Defence was already likely to be activated and responding,  Dr Cave said.

Councillors Josh Wharehinga and Ani Pahuru-Huriwai said they supported the recommendation as property owners and future owners “should know what they’re getting”.

Dr Cave, replying to questions from Councillor Rawinia Parata, said including mud volcanoes on LIM reports was an internal council process which would not incur a cost to private individuals.

In terms of insurance, the risk associated with mud volcanoes was low compared to the risk of landslides and flooding.

Replying to a question  from committee chairwoman Mayor Rehette Stoltz, chief executive Nedine Thatcher Swann said any change to a LIM report would require council notifying property owners.

But she noted Dr Cave had already spoken to affected residents.

Cr Rob Telfer said he would prefer property owners be notified beforehand to “see how they feel”.

But Ms Thatcher Swann said LIM reports were based on science and report a fact, such as a hazard on your property.

They were not part of a consultative process.

The report before councillors said the next step would be to advise the council’s Consent Planning and Building Services office.

A technical paper being published in the New Zealand Journal of Geology and Geophysics provided an opportunity around that publication to produce communications with the public as part of an awareness campaign around natural hazards generally.