Christchurch City Council staff have their own doubts about accuracy of coastal hazard maps.
The city council has tagged 18,600 land titles with hazard warnings based on a Tonkin & Taylor report which provides maps of the coastline with projected inundation areas over the next 100 years.
Property developer Mark Munro is leading a residents’ campaign against the council move.
A submission to the district plan written by the council’s own staff says the hazard maps for the suburb of Sumner have several inaccuracies.
The submission says these would need to be changed.
Mr Munro says the whole matter seems to be heading for a judicial review.
He recently wrote to Prime Minister John Key, prompting three cabinet ministers to come to Christchurch last week where they announced a coastal hazard chapter would be taken out of current consideration of the replacement district plan.
However, the council is refusing to modify or withdraw the notices on land titles.
They have potential to significantly devalue properties and raise insurance premiums.
According to a January High Court ruling on a similar Kapiti council case, Justice Joe Williams confirms there is a legal obligation to place hazard information on land titles but the question is over what information and how it is worded.
Justice Williams says the lines on maps based on projections have been found to lack scientific rigour and should not be used, even though information about potential erosion must be included on LIMs.
“The (Kapiti) council has concluded that the Shand lines cannot now be said to describe the extent of potential erosion in 50 and 100 years’ time.
“In other words the work done to support the lines is not sufficiently reliable to establish reasonably possible worst case scenarios at 50 and 100 years from the present,” Justice Williams concludes in his January 2015 ruling.”
Christchurch City Council chief executive Karleen Edwards has instructed legal staff to look at the matter.