Friday, March 4, 2011
Owen McShane: Sustainable Cities, Liveable Cities or Resilient Cities
While some might think it is crass to even be pondering such matters, rather than focusing on saving lives and cleaning up the mess, many people in Christchurch are asking these kinds of questions about their urban area while many throughout the country are asking similar questions about the future of their own towns and cities.
It does seem to me that our planners should stop worrying about sea levels rises that MIGHT, or might not, happen in 100 years – with plenty of warning – and start thinking more about making our cities resilient in the face of catastrophic events which we know can happen tomorrow – cyclones, volcanoes, earthquakes and tsunumai.
E.g. Don’t put our motorways in tunnels below sea level. Don’t further intensify the central city, especially near the harbour edge.
I suspect that, given the trauma in Christchurch, the city will be re-built as a multi-nucleic low-rise decentralised urban area.
No matter how good the structural engineering, many Christchurch people will now be reluctant to work in buildings more than a few stories high. And any CBD will probably be built somewhere else – or parts of it will be – to avoid liquefaction.
The Cathedral and its Square are potent symbols of Christchurch – as the Eiffel Tower is for Paris – and may be worth rebuilding for that emotional context.
But the new Auckland Council should take note that all cities in NZ are prone to catastrophe, and the forthcoming "Annual Plan" and “Spatial Plan” should embody this reality.
However, the proper debate should not be as simple-minded as "high rise vs low rise" or "old vs modern". I suspect that liquefaction will have contributed to the collapse of some of the modern strong buildings. In the Kyoto earthquake some high rise blocks simple fell over but remained in one piece because of the total collapse of the ground under the building. One advantage of low-rise buildings is that people can get out of them quickly and there is less “stuff” to fall down on top of them.
Then there is the furniture inside the building. If all the bookshelves in a school library all end up against one wall it’s not very nice for the kids inside. Fortunately, in the Alaskan earthquake, where this happened, the kids had just gone home. The quake struck at 3.30.
Anyhow, these sort of problems and issues are not solved by sets of simple rules but by the application of skill, experience and wisdom. We can only hope that this dreadful event in Christchurch will provide an opportunity for urban policy makers and engineers to gain all three.
Of course, some enthusiasts will want to see Christchurch rebuilt in their own utopian image, presumably driven by special regulation. Some draw on the precedent of Napier which was rebuilt after the Napier earthquake of 1931 with an "enduring Art Deco theme."
But in those days there was not even a Town and Country Planning Act to regulate urban design. Art Deco was all the rage at the time, and I suspect the few architects who were in Napier during the thirties seized the opportunity to demonstrate their flair and trendiness.
If anyone tries to impose a new set of objectives or design guidelines on Christchurch, the communities of the urban area, will have to go through the lengthy LTCCP and RMA processes, presumably with an embargo in place while the new regulatory regiime is all sorted out.
This is what happened (or was tried) in New Orleans and resulted in a couple of hundred thousand households departing for places where they were able to re-house themselves without waiting for bureaucratic consensus.
So I believe any “world leader” guide-lines would have to implemented solely by persuasion and involve no extra costs of DURT (delay, uncertainty, regulation and tax).
That is surely the lesson to be learned from the rebuilding of Napier.
at 11:21 PM