Specialist marine contractors will soon begin removing the remnants of Mount Maunganui's artificial surf reef, reducing 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 has 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.

The partial removal marks the final chapter of the 14 year experiment using large sandbags to try create a better surf break.

The Mount Maunganui Reef Trust obtained resource consent in August 2000 to construct the offshore submerged reef about 250 metres offshore from the Tay Street/Marine Parade corner.

The $1.5 million reef, built by the Mount Maunganui Reef Trust from 2005 to 2008 through donations from the public and community funding groups, never functioned as intended.

The reef's five year consent lapsed in 2010.

BOP Regional Council deputy chief executive Eddie Grogan says several companies tendered for the removal, and specialist marine contractors Underwater Solutions Ltd will start work from Tay Street beach soon.

The reef's removal is expected to take up to two weeks in good weather. The work will be signposted on Tay Street beach, asking water users to keep away from the barge.

The tops of the large sandbags which form the reef will be removed and left for a few days for the tide to remove some of the sand, says Eddie. The bags will 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.

'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."

Eddie says 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 will likely eliminate health and safety and environmental issues.

Frequently asked questions – Mount Surf Reef partial removal project - from BOP Regional Council.

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.

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.

Given the risk to swimmer safety, it is quite urgent to remove it. Partial removal is most likely to alleviate the risk.

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.

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.

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.