Re-homing fish an option for canal repairs
Hundreds of thousands of salmon may have to be temporarily rehomed while work to repair worsening leaks in the Tekapo canal is carried out.
The repairs, which could cost power company Genesis up to $125million, and will involve an in-flux of 150 workers to the site, are expected to take two years and will affect the Mt Cook Alpine Salmon farm.
Mt Cook Alpine Salmon chief executive Geoff Matthews said several hundred thousand fish might have to be re-homed or oxygenated.
"There will still be water, it just won't be flowing. We have known about this months in advance," he said.
Mr Matthews said there would be close to 800,000 salmon in the canal around the time of the repair work.
"We will harvest the mature fish, and oxygenate or possibly re-home some of the adolescents," he said.
Central South Island Fish & Game chief executive Jay Graybill said there were also tens of thousands of wild trout in the hydro system, particularly large trout.
"There are contingencies in place in the event that fish become at risk," he said.
Genesis spokesman Richard Gordon said yesterday the state-owned generator was lowering Lake Tekapo to its minimum operating level for remedial work before its planned shutdown of the canal from January 14 to April 21. This would be followed by a similarly long shutdown in the summer of 2013-14.
"Once the canal is out of service, inflows to Lake Tekapo will be captured within the lake. The lake will fill and eventually, if and when the lake reaches maximum control level, the lake will spill to the Tekapo River," he said.
The total cost for the repairs project was $125m.
Mr Gordon said repairs would fix worsening leaks, most of which were about 8km from the Tekapo A power station.
Temporary watertight structures known as cofferdams would be installed to allow the work to proceed.
The Government directed Genesis to purchase the Tekapo power stations from rival state-owned generator Meridian last year.
"This is a major project, and should provide certainty to the structures for at least another 50 years once complete," Mr Gordon said.
Up to 150 people would be on-site at the peak period of work.
Genesis will also undertake work on a major section of earthworks on the Tekapo-Pukaki canal known as the Maryburn Fill, near Lake Pukaki.
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