The Tasman District Council has decided to do nothing about erosion on Jackett Island, saying the $53 million cost of cutting a channel and maintaining it for 35 years is not financially sustainable.
The news stunned and angered island residents at a council engineering services meeting this week.
The council will challenge an Environment Court order to maintain a protective stormwall in front of the Van Dyke Family Trust's home on the island.
It will also challenge a court order awarding the family $252,000 in court and investigation costs, following an Environment Court ruling that a former council-owned groyne caused the erosion.
The court had also ordered the council to find a sustainable long-term solution to the erosion.
The court found in 2011 that after the groyne was built on the northern side of the Port Motueka channel, a sandspit formed, which forced the channel's water past the island's foreshore, eroding it by 30 metres over eight years.
The council removed the 700m groyne last year.
The council's transportation manager, Gary Clark, told the meeting that the cost of cutting a channel through the spit and using the sand to replenish the island's beach was estimated at $7.26m.
Maintaining the foreshore and the channel for the next 35 years would cost an additional $46.7m.
Mr Clark said the work was not financially sustainable. "The nub of the matter is the cost of carrying out the physical works and maintaining the channel are significant compared to the value of the land we are trying to protect."
He said subsequent council modelling had shown that the groyne did not cause the erosion.
Ben Van Dyke, whose family trust won the court orders against the council, said outside the meeting the council risked losing much more by going back to court with flimsy evidence.
He said the council had spent two years avoiding its responsibility, and the process had become an "exercise in futility" for his family.
"When is this going to end?"
He said the council had costed digging a major shipping channel through the spit opposite the port, "which is not going to fix the erosion". His family backed a small breach through the spit to the north, in the area of the historic channel.
Island landowner Michael Rae told councillors during the meeting's public forum that the court had identified the island's residents as stakeholders, but only two meetings had been held with council staff. He said the decision-making process had been confidential, and now the council was saying it would do nothing.
Fellow landowner David Dobbe said there had also been significant erosion of his family's land, and his family trust was not happy with the council's do-nothing conclusion. The family had paid rates on the land for 40 years, and now it was time for the council to re-instate the damaged coastline.
Mark Lyle, of the Port Motueka Users Group (PMUG), said information gathered from contractors indicated that the council's cost estimates for the work were grossly overexaggerated.
PMUG member Doug Saunders-Loader said the council should be considering a collaborative approach which considered alternative costing and options. He said the council's estimated costs were surprising.
Another resident, Brian Rhoades, said the council had not learned any lessons about consultation.
"At no stage have we been able to get together. The degree of consultation has been minimal."
The council had not given residents any information about the island's coastal processes, despite promises, he said.
A report by transportation planning officer Sarah Downs said the erosion was shifting further south. Mr Clark said the spit was extending, and landowners at the island's southern end could consider court action.
Cr Kit Maling was concerned about the lack of council consultation with landowners. "I don't think the council can do anything when we consider the costs - but my real concern is that we did not talk to the people."
Cr Paul Sangster said he did not want the council to walk away from the situation. He supported the council considering any solutions by private enterprise.
The meeting also heard that the cost of last year's removal of the geo-textile groyne had doubled to $711,056. Mr Clark said this was because of the difficulties involved in digging it out from the sand.
THE JACKETT ISLAND SAGA
1996: The Tasman District Council builds a groyne on the northern side of Port Motueka's channel, in a bid to keep it clear.
2010: Jackett Island couple Ben Van Dyke and Miranda Wood-Van Dyke take the Tasman District Council to the Environment Court. They argue that the groyne's impact has eroded 30 metres from the beach of their coastal property.
March 2011: The court finds in the Van Dykes' favour, ruling that the groyne was responsible for the erosion. It orders the council to remove the groyne, find a long-term solution and pay $252,000 in costs.
December 2011: The council hears estimates that a long-term fix involving dredging new channels could cost $3.7 million to $10.5m. Building a series of rock groynes along the island could cost up to $12m.
July 2012: The groyne is removed.
August 2012: The Van Dykes go back to the Environment Court, alleging a lack of council action to fix the problem.
November 2012: The council is told that $130,000 has been spent on investigating solution options, including maintaining a sandbag wall in front of the Van Dyke home.
February 2013: The council decides to challenge the Environment Court rulings.
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