A high-wire act involving ropes, harnesses and a cherry picker has been needed to stabilise a cliff behind a Dunedin church.
The Church of Jesus Christ of Latter-day Saints in St Clair has contracted Christchurch company Abseil Access to stabilise the cliff so rock remains in place in the event of an earthquake.
Abseil Access site supervisor Geoff Ellis, of Wanaka, said the work, which was "not cheap'', was expected to take up to 30 days.
Five workers would be on site most of that time.
The work involved bolting in place unstable rocks that could come down in seismic activity, and carrying out erosion protection by shotcreting an exposed layer of volcanic ash layer.
"That ash layer is actually causing the failure of the blocks [of rock] above, because as that erodes out, it undermines the blocks and they are dropping out.''
The cliff had been left exposed by previous quarrying in the area.
Ryman Healthcare has stabilised another section of the cliff, behind the company's Frances Hodgkins Retirement Village.