Anthony Stringer outside the cordon of his condemned house after his family was moved to a temporary accommodation. Photo / John Stone
A combination of rain and nearby earthworks on a subdivision led to structural damage on a residential property and sagging land around it, the Earthquake Commission has found.
The commission hired Opus to do an assessment of the property owned by fabricator Anthony Stringer, of Manuka Pl in Raumanga, following a claim he filed for natural disaster damage.
However, Opus made it clear the conclusions and recommendations in its report were based on a visual assessment of the site only and that subsurface conditions may vary.
Former Whangārei mayor Stan Semenoff has a resource consent to develop a large swathe of land overlooking Rewarewa Rd and South End Ave close below the Stringers' house.
Semenoff said since his surveyors, civil engineers and a geotech engineer were currently investigating and monitoring the land area in question, he was not in a position to comment on the Opus' report.
"Their final geotech report is not yet available as investigations are still ongoing."
A Whangārei District Council engineer moved Stringer and his wife to a temporary accommodation in late August after extensive cracks were found in their house.
They have put up a fence around their property as required under the Building Act and are staying in a flat provided by Stringer's employer Culham Engineering on its Hewlett St site.
WDC has issued a Dangerous Building Notice to the home owners and ANZ Bank as the mortgage holder and listed a number of remedial works they need to do within stipulated timeframes.
Opus inspected the property on September 3, particularly to determine whether physical loss or damage to the house was imminent as a direct result of a natural disaster or rain that fell on July 29.
It said the landslide was initiated in the neighbouring property and subsequently regressed into the Stringers' house following the July rainfall.
"We consider that the landslide damage would not have occurred if the earthworks development on the neighbouring property had not occurred first.
"As such we believe the neighbour in developing that land has not met all their responsibility under the conditions of the Resource Consent and the principles of the Resource Management Act 1991 section 17, namely to ensure that any earthworks operations undertaken do not impact adversely on neighbouring properties."
Opus said within the next 12 months under normal annual rainfall forecast and as a direct result of the landslip that has occurred, there was imminent risk of continued landsliding of land on which the house sat.
"We do expect that the landslide headscarp will regress with the 12-month period another 3m beneath the property causing new evacuation of 62sq m and additional damage to the house foundations."
EQC wrote to the Stringers on August 19 to explain that a registered valuer would value their land and/or retaining walls. An estimator would then prepare a scope of works to calculate the reinstatement cost of their claim.
When various reports are received, their claims manager will review them and a decision would then be made whether or not to accept their claim for damage.
Stringer said a copy of the Opus' report has been given to his insurance company while he was waiting for other technical reports.
He has managed to move most of his belongings from the condemned house and wasn't sure what the future held for his family.
Any remedial work he chooses to do will require resource consents and costs are expected to run into tens of thousands of dollars.
A Give-a-Little page opened about a month ago has so far raised $2675.
The Northland Regional Council which issued the resource consents to Semenoff said it would await technical reports before commenting.