Salmon farming in the upper Waitaki hydro canals over the past 18 years has had no effect on water quality, a study released this week by the Mt Cook Alpine Salmon Company says.
Aquaculture specialist Prof Terry Bradley, who also serves on Mt Cook Alpine's board as its technical director, was asked by the company to carry out the study.
It was based on data collected every six months since 1993 as a condition of resource consents by Environment Canterbury.
Company chairman Jim Bolger said water quality was a primary concern.
News there was no effect from salmon farming on water quality in the Tekapo and Ohau canals should be welcomed by the region.
"Salmon farming in the upper Waitaki catchment is set to drive economic growth in the area over the next decade," he said.
Prof Bradley said historical water graphs clearly showed the farm at its current level of production had no effect on water quality today or in the past.
Water quality was monitored above and below the salmon farm.
"Scientifically, this is so close to zero that it can be considered a nil effect," he said.
Water quality below the farm was better than safe drinking water standards and as good as bottled water consumers actually paid for.
Even at full production, water quality would be well within New Zealand drinking water quality standards, he said.
The company had now asked Prof Bradley to model the effects of the farm at full expansion and would publish the report when it was completed.
Data from the study is available on the company's website.
