Geothermal Rotorua

Post date: May 03, 2019 4:52:42 AM

By Peter Brownbridge, Geothermal Inspector, Rotorua District Council

Photo: Peter being interviewed for TV

Peter Brownbridge is being interviewed at GeyserCon for the session "Geothermal Apocalypse" - to explore with us what a geothermal disaster scenario might look like and what we should be preparing for in fiction, and perhaps in real life.

We asked him to introduce himself here for our attendees.

I have lived in Rotorua for the past 35 years and started work for the Rotorua Lakes Council in 1993. In 1995 I transferred to what was then known as the environmental services department, within which group the geothermal inspector (Bill) was based. Bill had held this role for a number of years and was very knowledgeable on all things geothermal here in Rotorua. Bill was nearing retirement and was looking for someone to take on the role.

It was never planned, however over the next five years I helped Bill out in his role of Council's Geothermal Safety Officer. It was during this time I met a local geologist who spent a lot of his time working in and around the geothermal activity in our area. For the next 8 or so years until he moved to Australia I would get carted to all sorts of geothermal related sites and incidents. This time taught me a lot about the geothermal fields in and around Rotorua.

When Bill retired in 2000, I was deemed the Council expert on all things geothermal, and the job was mine.

Bill's retirement coincided with the geothermal aquifer under Rotorua undergoing a period of recovery after the bore closure program of 1987-89. We were experiencing geothermal surface feature recovery including hydrothermal eruptions in and around Rotorua. Some of these were occurring under dwellings.

This was an exciting time as this sort of thing was new to all of us, mistakes were made and lessons were learnt, buildings were lost and saved.

In the end, Rotorua and I survived. Just when I thought I had everything under control the geologist informed me he was off to Aussie to live. And true to form, over the next few years there was a run of geothermal bores failing and going rogue, deadly gases venting into houses, and more geothermal surface activity. I was on my own and learning fast but feeling more and more comfortable with my decisions.

The end result of the above is that I'm now comfortable around all things geothermal, I understand how it works and what is going on under my feet.

I do not like the term "expert" - I do however consider myself knowledgeable on the geothermal system I live on top of and with this knowledge comes an awareness of the hazards it poses if things should go wrong.