St Clair Beach. Photo: RNZ / Tim Brown
Dunedin City Council has voted to park any immediate plans for reinstalling a groyne at St Clair Beach.
First-term Mayor Jules Radich pushed for the reinstallation of the groyne - a line of wooden poles that traps sand and protects the beach - during the previous term as a councillor, and made it part of his campaign for the mayoralty.
Once voted in, he led an unsuccessful bid to build the structure without the need for resource consent.
A report which went to council on Monday said it was estimated rebuilding the 1919 wooden groyne could cost up to $720,000, with annual maintenance and monitoring costing up to $110,000 every year of the hoped-for five-year trial.
But at [https://www.rnz.co.nz/news/national/456997/dunedin-city-council-wants-plan-that-addresses-coastal-system-as-a-whole Monday's meeting the council agreed that any plans for a future groyne should be included in its ongoing work to manage and protect the wider area.
Councillor Steve Walker said he was pleased plans for a trial groyne were done.
"I can't resist the pun - I'm absolutely delighted that option one [pursuing a resource consent for a groyne trial] is dead in the water. It's an old solution to a contemporary problem and it would've been an expensive trial in an extremely fiscally constrained environment, and I'm glad it's gone," he said.
At the meeting councillors heard the council employed only a single coastal specialist - a position that until recently had sat vacant for months following the resignation of the previous person in the role - and pursuing the trial would divert their attention away from the other work needed for the management plan of the whole Ocean Beach area, a wider area which included the St Clair, St Kilda and Middle beaches.
The plan to revisit the need and potential effectiveness for a groyne as part of that work was supported by the entire council, though some disagreed with allowing the Otago Regional Council to dictate the terms under which a groyne might be built.
"The history of the world has been the history of coastal erosion," Councillor Lee Vandervis said.
"We've always had it. This century's problem, as I see it, is the extraordinary amount of paperwork and risk aversion and duck shoving of responsibility before actually anything is really done.
"There's a lot of talk about the work that's involved and last century work involved putting poles in the ground and actually getting a result and seeing if it worked or not. These days it seems to be endless amounts of paperwork and you can spend $100,000 on this kind of work before you can even begin to build a house."
Mayor Radich remained convinced of their effectiveness, claiming it was only when the last remaining poles of the wooden groyne were damaged during a storm in 2015.
"Since then erosion has really taken off," he said.
Two days after winning the election last year, Radich told RNZ's Morning Report that sea level rise caused by climate change was not a threat to Dunedin's coastal environment as "the ocean is quite cold".
Multiple experts had told the council they did not believe groynes would be appropriate to retain sand at the beach and others had raised that groynes typically trapped sand on one side of the structure while it was lost on the other.
"Our modifications have created the problem because it's the seawalls that have been installed at St Clair since 1878 and several of them in the beginning that created the problem," Radich told the meeting. "And the only answer that worked was installing groynes at St Clair. In 1902 they first were and in 1921 they put in pair and in 1955 they fixed them up again, and they lasted for half a century."
The issue of division in the scientific community was explored today with the council's general manager infrastructure services Simon Drew acknowledging if 10 experts were canvassed for their opinion on groynes at the beach, they would likely give ten different opinions on their effectiveness.
The council requested a report on the inclusion of groynes as part of the St Clair-St Kilda Coastal Plan, so it could be explored during the upcoming ten-year plan consultation process.
