Councils respond to Fish & Game challenge over Lake Ngāroto

Waipā-King Country Waikato regional councillors Andrew MacPherson (left) and Stu Kneebone facilitated a meeting to discuss ongoing issues at Lake Ngāroto. Photo / Dean Taylor

The challenge laid down by Auckland/Waikato Fish & Game Council game bird manager David Klee in his open letter regarding the state of Lake Ngāroto, published in last week's edition of the Te Awamutu Courier, prompted a response from the two authorities charged with the lake's care.

Heading the response was Waipā-King Country Waikato regional councillor Andrew MacPherson, and constituent colleague Stu Kneebone, who facilitated a meeting at the lake to discuss the issues.

David Klee was in attendance, alongside Hamilton Waikato regional councillors Angela Strange and Jennifer Nickel, WRC zone manager-Waipā Keri Neilson, WRC lake scientist Dr Mat Allan, Waipā Mayor Jim Mylchreest, Deputy Mayor Liz Stolwyk, councillor Lou Brown, Waipā chief executive Garry Dyet, and WDC acting community services manager Brad Ward.

Waikato Regional councillor Andrew MacPherson (right) welcomes interested parties to Lake Ngāroto. Photo / Dean taylor

Andrew said he believed David's open letter was directed at the wrong audience, and that Waikato Regional Council and Waipā District Council took stewardship of Waipā waterways and peat lakes seriously and had made huge strides over the years to protect and restore them.

David responded to say his criticisms weren't aimed at the councils, staff and councillors directly, but at what he described as a glossing over of the facts that was hindering an open and truthful conversation that would lead to meaningful solutions.

He said anyone who believed the hype that the toxic lake level was a natural occurrence was hindering progress.

"I agree Waipā District Council is a leading example and has tried its best with Lake Ngāroto, but the fact is the lake is regressing despite those efforts," he said.

He believed it would take tens of millions of dollars and decades to restore the lake, but it should be done.

David said it was important we don't let other lakes go the same way.

"We need other solutions. If we keep doing the same thing we will only get the same result.

"I don't believe any lakes are improving. Some are stable at best."

Waikato Regional Council zone manager for Waipā, Keri Neilson, explained the scope of some of the work undertaken to protect the district's waterways.

These included modelling of four lakes to understand and improve water quality, working with landowners to retire unsustainable farmland, purchasing land, and construction of treatment systems and developing scenarios to achieve water quality goals.

She said these projects are on top of other substantial projects and represent a massive amount of work and a huge investment, but even then the desired outcomes might not be possible.

Waikato Regional Council lake scientist Dr Mat Allan gave more in-depth information about the lake.

He said the restoration of Lake Ngāroto is a huge challenge because the lake has "flipped" into a suspended algae/phytoplankton and sediment dominated state - mainly due to excess nutrients derived from the lake catchment, and now stored in the lake sediments. This state is exacerbated by the presence of pest fish such as Koi carp.

"The current situation began with a large algal bloom at the end of November, which then collapsed, with the associated decay of dead algae and calm warm conditions resulting in hypoxic or anoxic conditions," he said.

"This led to the death of fish and other living organisms in the water. Subsequently, another toxic algal bloom developed in January, alongside botulism outbreaks, resulting in dead and dying birdlife."

The toxicity levels presented a danger to humans and animals, and led to the closure of the lake for health reasons.

The rain and wind event over the weekend has helped to restore lake oxygen levels, but there is still potential for further blooms this summer.

"New modelling is being undertaken to address the factors that have caused the current state in Lake Ngāroto, and set targets for inflowing nutrients to the lake, hopefully restoring lake water quality, but it is acknowledged it is a difficult task."

Waipā chief executive Garry Dyet said he and the mayor had worked hard for a number of years to get the policy settings in place to slow down the degradation of peat lakes.
He believed in terms of riparian strips, lake levels and land use they had the knowledge about what was needed and the incentives in place to make it happen.

Garry said council was going as hard as it could.

Jennifer Nickel, who is the regional climate action committee chairwoman, said we needed honesty about climate change to change the understanding around the economic and social impact it has.

"We need long-term thinking for strong sustainability and prosperity," she said.

"We must prioritise the environment to get those economic and social outcomes."

Councillor Stu Kneebone said as a fourth-generation dairy farmer, he had seen huge gains over the past few decades, from a time not long ago when there was no regulation.

He believes landowners have adapted to a highly regulated environment, although it hasn't always been easy.

"We have an 80-year timeframe, which involves plans we have made and hopefully new technologies and developments.

"We think we are ambitious and have made big strides with the funding we have had available."

Deputy Mayor Liz Stolwyk said community buy-in to any plan and project was vital to its success.

"It is important we bring the community on the journey," she said.

Mayor Jim Mylchreest said the challenge from David felt personal, and he believed it wasn't constructive.

He set his own challenge; asking the experts if we should be thinking outside the square and trying something innovative.

"I look at the example of Maungatautari, which I was heavily involved in," he said.

"The community took a punt and tried something new and unproven in an area that the Department of Conservation had all but given up on.

"It took a huge community buy-in, but the result is New Zealand's pre-eminent restoration project."

From left: Dr Mat Allan - Waikato Regional Council lake scientist; Auckland/Waikato Fish & Game Council game bird manager David Klee; Waikato Regional Council zone manager - Waipā Keri Neilson.

Dr Mat Allan responded, and said there is some evidence large-scale aeration, or micro-bubbling aeration, might be a solution for the lake.

"It would require extensive modelling of the theory and then controlled experimentation to gauge the effectiveness.

"Another possibility is to treat for nutrients and lock up the phosphorus using products such as Phoslock or Zeolite.

"However, these substances would need to be monitored for potential chemical and biological effects on the lake ecology.

"We note here that long-term lake restoration requires a large reduction in nutrient loads derived from the lake catchment."

Mayor Jim concluded by saying he believed Waipā had the will to do better, but whether this community had the wherewithal to achieve it on its own was questionable.

He agreed though it was most important that everyone was on the same side and everyone worked together.