Contact plan has Taupo residents steaming

By JO-MARIE BROWN

Contact Energy will square off against Taupo residents next week when the company tries to renew its resource consents to continue operating the Wairakei geothermal power plant.

The electricity generator faces a mountain of opposition from residents and the Taupo District Council, who believe the company is causing subsidence problems in and around the town.

More than two dozen properties on the eastern outskirts of Taupo have doors and windows which stick and cracks appearing in walls and driveways.

Residents say Contact is to blame because it does not re-inject all of the geothermal fluid it takes from the Wairakei field, and they are appalled the company now wants to increase the quantity it draws off by almost 45 per cent over the next 22 years.

A month-long resource consent hearing will begin on Monday at which 199 submissions will be considered. Of those, only two fully support Contact's proposals.

Contact says it is not clear what has caused subsidence to occur in parts of town but the company does not believe that deep geothermal extraction is responsible.

"The affected area is volcanic and there are quite a number of possible reasons that are probably more likely," said Contact spokesman Gary Johnson.

Test results from bores drilled near the subsiding homes late last year were due out shortly and would hopefully provide more information about the cause of the problem.

But Mr Johnson said even if Contact was at fault, re-injecting all of the fluid back into the geothermal field was not a viable option.

"It's our understanding that it may actually worsen subsidence in that area," he said.

Contact discharges over half of its geothermal fluid into the Waikato River once the heat from it has been used to generate electricity. The remainder is re-injected underground on the outskirts of the field.

Mr Johnson said complying with the residents' request and re-injecting fluid into the same place it was taken from would ultimately shorten the life of the geothermal field.

But the Taupo council's legal officer, Chris Gilbert, disagreed and said overseas experts would appear at the resource consents hearing and offer contrary evidence.

"There's no geological reason why they can't [re-inject into the field], there's only an economic one," Mr Gilbert said.

The council had spent over $1 million preparing submissions on the issue as it was one of the most significant problems facing Taupo.

"For a small council it's a huge expense but we feel we have to do it because we have to protect the town," he said.

"The effects of the extraction are such that it could mean parts of the town can't be developed because of the subsidence risk."

The plan

* Contact Energy wants to renew resource consents for the Wairakei geothermal power plant near Taupo.

* It wants to increase the quantity of geothermal fluid taken from 170,000 tonnes a day to 245,000 tonnes by 2026.

* The additional fluid is needed to maintain the electricity supply because the Wairakei field is getting cooler.

* Capacity will also be boosted at Contact's nearby Poihipi power station.

* Taupo residents and council oppose the plan and blame the company for land subsidence.