Update from Roger Sutton, Chief Executive: 5 March 2012

Release Date: 05 March 2012

Mr Roger Sutton. Since the latest round of land rezoning announcements on 10 February, several Southshore residents and their representatives have asked, “Why the delay?” in rezoning the remaining orange area in their suburb.

I understand the frustration. This long strip of homes down from South New Brighton Park to the Spit Reserve and on the western sides of lower Estuary and Rocking Horse roads has 401 of the 653 properties still zoned orange.

The number may seem small considering the more than 10,000 orange properties when zones were announced in June 2011, but for remaining property owners it is a big issue, making it much more difficult, post-earthquakes, to move on with their lives.

Rezoning this area of Southshore in the coming weeks, plus the smaller remaining orange zones along the Avon just east of the central city, is an absolute priority for us.

The reality is this work is demanding, detailed and difficult. While we’re extremely conscious of impacts on those who are waiting, we’re also aware these decisions need to be well-informed, well-considered and robust. The properties remaining in orange zones are the hardest to rezone, and in many cases face several land damage issues.

It is important readers avoid trying to speculate on how remaining areas might be rezoned. Until a final decision is made, speculation is not always helpful. In Southshore, while most geotechnical works are now done, investigations into potential remediation and rebuild options, including reviewing cost estimates are still ongoing.

Unlike suburbs further inland, the estuary edge has little in the way of a surface “crust”, in other words the land is softer and may need deeper piles or stronger horizontal foundations.

About 60 per cent of the properties had moderate to major lateral spreading and the best information available so far suggests half the properties in this area require rebuilding because of it. Lateral spreading means the land has moved horizontally in earthquakes and any rebuilding would need to mitigate this risk either with a perimeter wall, or site-specific foundations, or a combination of both.

If such a wall was to be built on the land along the edge of the estuary for about the length of the current orange zone, there would also be ecological, archaeological and surveying issues to consider, as well as the impact on the residents. There has been no decision on any one remediation system yet.

An alternative may be new foundation solutions allowing owners to rebuild in areas where moderate lateral spreading may occur in future earthquakes. Guidelines on possible new foundation solutions are under development by the Department of Building and Housing.

Yet another issue in the Southshore orange zone is that the land is believed to have dropped about 150-200mm and some houses may have dropped slightly more. Long term implications plus changes in the estuary bed which may affect homes along the estuary edge are still under investigation and these issues are unique to Southshore as opposed to other orange zones.

As I said, every effort is being made to rezone Southshore and the other orange areas as soon as possible and we will do our best to keep people updated as progress is made.

Roger Sutton
Chief Executive
CanterburyEarthquake Recovery Authority