Auckland Council has served an abatement notice on developer Te Arai North Limited (TANL) following the construction of a modified weir that environmental groups say threatens the survival of New Zealand’s most endangered bird species.
The Save Te Arai pressure group, the New Zealand Fairy Tern Charitable Trust and the Te Arai Beach Preservation Society complain that the weir on Te Arai stream threatens the New Zealand fairy tern, along with other birds such as the dotterel, Caspian terns, variable oystercatchers and pied stilts.
Their concerns have been echoed by Council staff, who have noted the modified and heightened weir has the potential to impede the passage of fish and have adverse effects on fish spawning habitat.
This, in turn, adversely affects the birds who depend on the fish for food.
According to the Fairy Tern Charitable Trust, the fairy tern, with a population of just 35 to 40 birds, is especially at risk.
Trust convener Heather Rogan says the Te Arai stream mouth is one of the most important post-breeding flocking sites for the fairy tern, with at times, 50 per cent of the total population gathering there to feed and teach their young how to fish for themselves.
“The importance of a reliable fishery at Te Arai for the survival of the NZ fairy tern cannot be overstated,” she says.
Save Te Arai chair Aaron McConchie says in addition to the bird and fish threat, earthworks associated with the weir have narrowed the water channel, resulting in water flowing at a higher velocity, causing scouring downstream.
Meanwhile, any flooding upstream is exacerbated as water is impeded because of the weir “choke point”.
“All of the erosion problems we have had in recent months has only occurred after doing all this work. It’s clear human input has caused all these issues. We never had any issues in the past,” he says.
Council compliance and resource consents manager Steve Pearce says the weir does not comply with Auckland Unitary Plan rules, nor does it have a necessary resource consent. The abatement notice demands the weir either be removed or else TANL must apply for a retrospective consent.
But TANL has dismissed the environmental concerns, saying claims of negative impacts on fish, birds and flooding are untrue.
TANL spokesperson David Lewis says its ecologists have verified fish are able to cross the weir as they have for years and have photos of the fish passing through.
He says TANL disagrees with Council on the appropriateness of the abatement notice, maintaining it has complied with planning rules.
However, to resolve the matter it is open to reducing the height of the weir and securing a consent.
Mr Lewis also dismissed a suggestion that the purpose of the weir was to prevent salt water travelling further upstream where a nearby pumping station extracts water to supply the Tara Iti Golf Club.
“Due to our on-site storage capacity, we are able to manage our water take to avoid pumping any saline water,” he said.