In response, the Otago Regional Council formed a working group to push along a plan to protect the region’s lakes.
The council’s strategic lakes management plan is in a preliminary phase and is expected to inform the council’s 2024-34 long-term plan process.
This week councillors discussed an assessment of the merits of such a plan, the Otago Lakes Management Review, by Cromwell environmental consultancy Landpro.
The review found that although Otago's lakes were a critical part of the region’s identity, the council lacked an overarching strategy to protect them.
At the start of the discussion this week interim chief executive Pim Borren revealed he had recently received a letter from Simon Upton, Parliamentary Commissioner for the Environment.
In it, Mr Upton told Dr Borren he was concerned about the evidently deteriorating health of Otago’s three deep-water alpine lakes — Lakes Wanaka, Hawea and Wakatipu.
Drawing on a report by former Niwa biodiversity and biosecurity chief scientist Don Robertson, Mr Upton told Dr Borren he was concerned about the declining health of the "iconic lakes".
There was a lack of monitoring of the evolving conditions of the lakes and there was not enough research into the origins of the problems, nor identifying fixes, he said.
Land use and human activity had intensified in recent decades.
"Evidence indicating that the lakes’ water quality is declining is not matched by evidence-based management let alone specific research on these trends," Mr Upton said. "The lack of end-to-end research to identify and address the many issues affecting the lakes is particularly worrying.
"It is not that there is a lack of concern or commitment from research and community organisations.
"Rather, there appears to be a lack of targeted funding and an absence of the leadership needed to drive research in the right direction."
Dr Robertson’s report noted evidence of chlorophyll-a doubling in all three mountain lakes in the five years from 2016 to 2021.
Microscopic planktonic algae adrift in the lakes was increasing, likely due to human activity, it said.
Dr Robertson had spoken to the council before as chairman of Guardians of Lake Wanaka and a member of Guardians of Lake Hawea.
This week councillors directed staff to assess the costs a management plan might incur.
Dr Borren said Mr Upton’s view on the "lack of leadership" in protecting the water quality of those lakes might have been "partially accurate in the past, but it is not so today".
Dr Borren also said the council agreed with a proposal from Dr Robertson’s report for a large-scale Government funded research project on a scale of up to $15million over five to six years.
"We’re looking for assistance from central government to help us facilitate exactly the type of work you are asking about," Dr Borren said.
Council chairwoman Gretchen Robertson said protecting the region’s deep water alpine lakes was a matter of national significance and deserved Government support.
