Checks rule out instability as cause of fatal rockfall

Inna Rudyy-Collie. Photo / Supplied

Engineers inspecting Saturday's fatal rockfall on Auckland's North Shore have found no large-scale instability of the seacliffs between Rothesay Bay and Churchill Rd reserve.

In a report to the Auckland Council, geotechnical engineers said a tragic accident killed Mrs Inna Rudyy-Collie, 44, while walking her two dogs.

It was the first known fatality of its type in Auckland.

Although there was a risk to the safety of beach users, they said engineering works to secure cliffs would be extensive, expensive and difficult to construct.

The rockfall was part of the natural cliff line erosion process affecting most of the Auckland eastern coastline.

No engineering suggestions for safety measures were recommended except for putting up additional warning signs.

The report will go to the coroner's inquiry into Mrs Rudyy-Collie's death.

The Tonkin & Taylor engineers found recent rockfalls at three points along the 1km stretch of the cliff which is 30m to 40m high.

The fall at the accident spot was small and came from 20m to 25m above the cliff base.

At this spot, erosion of the sandstone-siltstones in the cliff face was at the lower range of the rate of 2m to 10m each 100 years.

Lack of gross defects or faults suggested generally minor rockfalls rather than large-scale instability.

"The risk of public danger due to rockfall has always existed at the site and the likelihood is considered to be very low."