Part of Mount Maunganui's artificial surf reef will be removed.
The Bay of Plenty Regional Council decided to partially remove the reef at Tay St to remove risk to swimmers.
Regional council deputy chief executive Eddie Grogan said the Mount Maunganui Reef Trust obtained resource consent in August 2000 to construct the pilot offshore submerged reef about 250 m offshore from the Tay St/Marine Parade corner.
It was to be part of on-going research into artificial reef development by the University of Waikato, as well as providing a superior surf break for surfers, however the structure was never fully completed.
The five year consent term granted lapsed in 2010 and the Regional Council, as RMA regulator, needed to consider options for its future management.
The $1.5 million artificial reef, built from 2005 to 2008 with donations from the public and community funding groups, has never functioned as intended and was criticised by surfers and the public. The reef has attracted criticism, with surfers saying it did not provide the intended surf breaks, and surf lifesaving organisations concerned it was creating dangerous rips for swimmers.
"The reef's expected positive effects have not been realised. It's also generated some unforeseen effects, including creating a large scour hole which affects waves and currents, increasing the frequency and intensity of rips which pose a serious risk to swimmers in the popular Tay Street area," Mr Grogan said.
"We have commissioned a specialist report to consider the effects on the beach, swimmer safety, navigation safety, surfing values, cultural values and ecology. The review evaluated three options - status quo, removing the reef and repair and restoration, and recommended removal."
The review recommended the reef structure be removed in a staged process. Removing the largest geotextile containers at a cost of about $60,000 would likely eliminate health and safety and environmental issues, it said.
While the Reef Trust had told the Council it would like to see the reef completed to achieve its original intent, it was not in a financial position to maintain, manage, re-consent or complete it, Mr Grogan said.
The Regional Council had to consider whether the reef could be left in its current state, or whether hazard or environmental issues meant it needed to be repaired or removed. There were significant costs involved in leaving the reef where it was, risks to swimmers at Tay Street beach and adverse environmental effects Mr Grogan said.
Repairing the reef could pose more issues, including altering coastal processes, changing currents and exacerbating risks to swimmers, Mr Grogan said.
Work is likely to start as soon as possible, following selection of a preferred contractor and weather conditions permitting.
1. Why are we proposing to remove the reef?
An independent investigation has established that the reef has deteriorated since it was installed, and identified a number of on-going environmental effects, including unanticipated changes to coastal processes. A particular risk to swimmer safety in the Tay Street area has been identified.
2. Why is the reef not performing as it was expected to?
The reef structure is not as it was originally designed. This is because of errors made during construction (including under-filling of the bags which make up the structure), removal of one of the major bags when it was damaged, and other damage and sand leakage over time.
Some of the assumptions made during the design process about how the reef would perform also appear to have been incorrect.
3. Is there any urgency for the reef to be removed?
Given the risk to swimmer safety, it is quite urgent to remove it. Partial removal is most likely to alleviate the risk.
4. Won't completing/rebuilding the reef structure to the original design solve the problem?
Unfortunately no. Completing/rebuilding the reef to the original design would require increasing the reef's size and profile within the water. The swimmer safety risk and environmental effects we have now will persist, and potentially increase as the reef's size and profile increases. Cost estimates for rebuilding the reef also indicate that this option would be prohibitively expensive.
5. Can the reef be retained until new technologies can provide a safe reef?
Given the swimmer safety risk and environmental effects, and the uncertainty about if and when the reef could be made safe and how this would be funded, it's not prudent to leave the reef in its current state indefinitely.
6. How will the reef be removed?
The suggested method involves a diver cutting open a number of bags, followed by at least two to three weeks to allow the sand from the bags to disperse. After this a diver would remove the empty bags and cut other bags so their sand can disperse. The empty bags would be barged back to land, with nothing left in the marine environment. There may be other methods, and these will be explored with the preferred contractor.
7. Will partial removal solve the problems?
Partial removal will likely alleviate the environmental and safety effects. We'll assess how successful the work is as the work is done.
8. Does removing the reef require a resource consent?
No. We're doing this work as part of enforcement for an existing resource consent, and because we have a responsibility to manage the ongoing effects of the reef.
9. Why wasn't the reef's removal considered when it was granted consent?
The resource consent was for a five year term only, anticipating that the reef would be removed after that. Some consideration was given to removal, and it was thought the removal process would be relatively straightforward. Experience with the Mount surf reef and reef projects in other locations has shown this is not the case.
10. When is the reef to be removed, how long will the partial removal take and who will do the work?
We propose to remove the reef as soon as possible once a contractor is appointed. With the suggested method, each removal dive exercise will take two days, with two to three weeks between exercises, and a minimum of three dives likely to be needed.
Marine conditions around the reef were an issue when the reef was being built, and have also delayed dive inspections while we have been investigating options. The work will be subject to weather and marine conditions, and this may affect how long it takes to remove it.