Tenders chosen for Mount surf reef removal
Wednesday, 17 September 2014 10:00 a.m.
Work will start soon on removing the Mount Maunganui surf reef to reduce the risk to swimmers near Tay Street beach.
Bay of Plenty Regional Council decided to partially remove the artificial reef earlier this year once its resource consent expired. The reef had attracted public criticism, with surfers saying it did not provide the intended surf breaks, and surf lifesaving organisations concerned it was creating dangerous rips for swimmers.
Several companies tendered for the removal, and specialist marine contractors Underwater Solutions Ltd will start work from Tay Street beach soon.
Regional Council Deputy Chief Executive Eddie Grogan said the tops of the large sandbags which formed the artificial reef would be removed and left for a few days for the tide to remove some of the sand. The bags would then be removed by barge.
“The sand inside the bags had been filled at the site so there are no issues with releasing foreign organisms via this process,” he said.
“There is already a lot of sea life attached to the bags, which was one way the reef has worked as intended. The undersea area will quickly return to its former state once the engineering works are completed."
The site would be surveyed once the work was complete, and then annually to ensure that natural processes had resumed and that partial removal of the reef had worked.
The Mount Maunganui Reef Trust obtained resource consent in August 2000 to construct the offshore submerged reef about 250 m offshore from the Tay Street/Marine Parade corner. The $1.5 million reef, built from 2005 to 2008 with donations from the public and community funding groups, had never functioned as intended.
The five year consent term granted lapsed in 2010 and the Regional Council, as RMA regulator, needed to consider options for its future management, Mr Grogan said.
“The reef 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.”
A specialist review recommended the reef structure be removed in a staged process. Removing the largest geotextile containers would likely eliminate health and safety and environmental issues, Mr Grogan said.
The removal work was likely to take up to two weeks and was weather dependant, he said. The work would be signposted on Tay Street beach asking water users to keep away from the barge.
Frequently asked questions – Mount Surf Reef partial removal project
Q. Why does the reef need to be removed?
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. This is part of enforcement for an existing resource consent, because the Regional Council has a responsibility to manage the ongoing effects of the reef.
Q. Why did the reef not perform as it was expected to?
The reef structure is not as it was originally designed 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.
Q. 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.
Q. 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.
Q. 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.
Q. 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 with regular surveys.