Digging on geothermal ground
All geothermal systems give off gas, and Rotorua's is the best known for the rotten-egg smell of hydrogen sulphide. Bay of Plenty Regional Council says the gas can reach lethal concentrations in contained or enclosed places, though it thins quickly in the open. Before anyone works in a trench, pit or under the floor, ask how they'll deal with that.
Building work or earthworks near a geothermal surface feature may need a resource consent from the regional council, the district council, or both. Ask before the digger arrives, not after.
Rotorua facts that change a job
Damp is more common
At the 2023 Census, 3.9% of Rotorua homes were always damp and 20.2% sometimes damp, against 2.3% and 15.8% nationally. Mould bigger than an A4 sheet was always there in 5.3%. A slow leak under a floor or behind a shower adds to it, so rule one out.
A bore of your own
Geothermal wells in use include production and injection wells and down-hole heat exchangers. The regional council says any of them can create health and safety risks, and casings wear out over time. Talk to it about a well before work goes near one.
Gas heaters above average
Fixed gas heaters were a main heater in 13.1% of Rotorua homes in 2023, against 9.5% across New Zealand. Gas pipes and fixed appliances need an authorised gasfitter.
A building surge
New dwellings consented in the Rotorua urban area rose from 60 in the year to March 2013 to 565 in the year to March 2025, then 260 in the year to March 2026.
Whose pipe is it?
Rotorua Lakes Council chose to keep water delivery in-house under Local Water Done Well. Whakatāne District Council lists it among the councils still looking at a joint water company, so its arrangements could change. For now, the council is the contact for the public network. Its site didn't let us read its pipe pages, so ask it where its responsibility ends before any digging near the street.
Is the licence current?
Before work starts, ask to see the PGDB licence, as a card or on the PGDB app, and check it covers the trade: plumbing, gasfitting and drainlaying are licensed separately. Search the PGDB register by the person's first and last name. A current licence shows a tick or green; an old listing doesn't count. Our licence guide shows how.
What we would do
Treat any job that means digging, especially near steam or hot ground, as one to ask about first: the regional council for consents and the district council for where its pipe runs. If you smell gas indoors and it's strong, get everyone outside before you worry about where it's coming from. For everything else, tell us the job, and the authorised Rotorua tradie who accepts it is the only one who gets your phone number.