Geothermal bore: Rotorua Energy Events centre and Sportsdrome evacuated due to high gas levels

It's not clear how long the Rotorua Energy Events Centre and Sportsdrome will remain closed after being evacuated today due to a geothermal gas leak.

Rotorua Lakes Council closed the facilities and cancelled events as a precaution due to the detection of higher than usual hydrogen sulphide gas levels related to the geothermal activity that closed Hatupatu Rd last week.

"The bore that was causing hot water and steam to come up through Hatupatu Drive last week was grouted shut yesterday, as was standard practice after an issue that can't be fixed is detected within a bore, and the surrounding area was cemented," the council said in a statement.

The cordoned off area behind the Energy Events Centre and Sportsdrome on Tuesday. Photo / Ben Fraser

It said the bore had been "quenched last week" and had been inactive, but today began heating again, causing gases and steam to escape outside the sealed area.

In response to Rotorua Daily Post queries, the council said it was suspected the casing below the area grouted last week had split. Work was underway to quench it again and when that was done, repairs to the casing could begin.

"At this stage, we cannot be certain how long the quenching will take. The buildings will be reopened when it is considered safe to do so."

It said there was no immediate risk to staff or anyone using the buildings, but the evacuation was done as a precaution to avoid the risk of any exposure to the gas, which could pose a danger to human health in "certain accumulated conditions".

The road around the bore remained closed and safety fences were still in place, with the public advised to stay well clear of the safety cordons.

"It's important that people avoid the bore site due to potentially unstable ground, very high temperatures from steam and water, exposure to hydrogen sulphide, and machinery and staff actively working on the site."

An empty Energy Events Centre carpark on Tuesday. Photo / Ben Fraser

The council said Worksafe was monitoring the situation as any geothermal issue of this nature had to be reported.

Early last week the council set up bollards and cones behind the Rotorua Sportsdrome on Hatupatu Drive related to a nearby bore which was causing steam and water to come up through the road.

It was thought the event was due to a casing failure, likely caused by ground conditions in the area, council said at the time.

More to come.