The Warkworth weir looking spectacular following heavy rains. Photo, Ian Anderson.
Auckland Council will press ahead with controversial plans to remove the historic weir on the Mahurangi River.
And it says the time for further discussion is over, despite howls of protest from outraged locals, who insist the weir must stay.
Council’s resolve was strengthened following the completion of a recently-released NIWA report, which reinforced its view that the weir restricts the passage of fish.
The report conceded that some climbing fish species could pass the weir, but went on to say that the structure largely obstructed non-climbing fish such as inanga – a species of whitebait.
The report stated that removal of the weir would have the best outcome in terms of restoring fish passage to natural conditions.
“The Bridgehouse weir is redundant and no longer serves any practical purpose, making it an excellent candidate for removal,” the report said.
The report said the installation of fish passes might be considered if removal was not an option, but passes in the river were largely prevented by “lack of space” and would require further investigation. It added that passes involved significant upfront and ongoing maintenance costs.
“On balance, weir removal appears to be the most practical and permanent solution for restoring fish passage at this site,” the report said.
It has revived a fiery debate. At a packed meeting in the Warkworth Town Hall in February last year Paul Decker, the manager of Warkworth-based whitebait farm Manaki, vigorously disputed Council’s case for removal to hearty applause.
Mr Decker’s views remain unchanged after reading the NIWA report, which he describes as full of misleading and inaccurate information and “not worth the paper it is written on”.
“The list of fish species that NIWA reports to be present within the Mahurangi River, above the weir, is so understated that it can only be assumed that the report was thrown together to make a fit with the weir’s destruction agenda,” he says.
Moreover, Mr Decker says the report totally ignores the fact that if the weir is removed it will allow for the establishment of redfin perch. He says the introduced perch have been implicated in the decline of many native fish species, including both inanga and smelt – the very species supposed to be saved by destruction of the weir. The perch already proliferate within the Warkworth cement-works lake, and during floods readily escape into the river.
“However, as they currently can’t swim any further up river than the weir, they die off as the saltwater levels return to that part of the river,” Mr Decker says.
Mr Decker says that removing the weir would not only be costly but would pose an environmental hazard, destroying a well-established environment that supports fish, freshwater mussels, invertebrates and an entire ecosystem.
He adds that if the weir is breached, 115 years of sediment “stinking in death” will wash down the river to kill even more habitats.
Other notable voices saying the weir must stay include Bridgehouse bar and restaurant owners, Ian and Ramona Holt, local historian David Parker, and Peter Thompson, of the Mahurangi River Restoration Trust.
Ian and Ramona say the weir should be retained for aesthetic reasons and they are willing to pay for a fish pass if that means it can stay.
“Imagine buying a house next to a river and all of a sudden somebody says we’re going to turn this into a creek,” Mr Holt says.
“It will wind up being a stinking little mess.”
Mr Parker says the weir has huge historical significance for Warkworth – the original one was built in 1844 by the town’s founder, John Anderson Brown, and was subsequently used to supply fresh water to several of the town’s early industries, located on the riverbank.
“Its proposed demolition will not be accepted by the townspeople or its pioneering families,” he says.
Mr Thompson says a “huge number” of townspeople are mobilising to save the weir with some putting up funds to try to secure a heritage order, which would ensure the weir’s protection.
Others were seeking a “robust discussion” with Council on the subject, saying that so far there had been no proper consultation.
Rodney Councillor Greg Sayers would also like Council to publicly consult on the report’s findings.
“My concern is that Council is saying that due to cost it isn’t promoting options such as a bypass channel, fish ramps or spat ropes, but these could be installed and potentially maintained by interested community groups,” he says.
But Council senior publicity officer Liz Kirschberg says there will be no further consultation with the community.
She says either Council’s Healthy Waters or Environmental Services department will seek a Certificate of Compliance (CoC) to facilitate the weir’s removal. But this is essentially a “rubber stamp” exercise. Once the CoC is issued, the only thing preventing removal of the weir is the budget to do it.
She says there is no budget in the 2020/2021 financial year, but it’s possible money could be available in 2022.