A detailed design for a buried backstop wall to halt erosion at St Clair and St Kilda beaches in Dunedin, including costings and drawings, will be completed in the next financial year.
The update was contained in a report for councillors considering the draft annual plan for 2013-14.
In it, council parks manager Lisa Wheeler noted there was no funding in 2013-14 for the backstop wall, which councillors approved last July as part of long-term measures to mitigate coastal erosion in the Ocean Beach Domain between St Clair and Lawyers' Head.
However, about $250,000 from this year's budget, which remained unspent, would be carried through to the 2013-14 budget and used to prepare an application to extend the current resource consent for emergency works in the area, which expires in 2014.
It would also be used to develop detailed costed design drawings for a buried backstop wall from behind the eastern edge of the St Clair seawall to the cultural centre.
It would be the first section of a buried wall that would eventually stretch to the St Kilda Surf Club.
Once the design work and costing had been done, staff would refer it to councillors for consideration against other projects.
In the long-term ''adaptive management approach'' for battling erosion along the Ocean Beach Domain, adopted by councillors last year, it was intended to install the wall in 10 to 15 years' time, but earlier if required.
Ms Wheeler said since July the council had spent $44,000 mitigating the effects of a storm on June 28, when 40-knot to 50-knot winds combined with 2.5m waves hit the coast and the Ocean Beach dunes, eroding sand at the end of the St Clair wall and the car park above Marlow Park.
A sand survey was under way at present, but the last one, in March 2012, showed there did not appear to be any abnormal sand movement from the beach, and no long-term trends apart from in front of the seawall, where fluctuations of sand levels were the greatest.
There was enough sand stockpiled at Tahuna Park ready for any emergency works after one more storm event.
The stockpile would be reassessed at the end of the financial year, when more would be brought in to retain the levels needed.
Historically the dunes were most vulnerable to damaging winds in May and June, Ms Wheeler said.
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