I like to compare the failure of a large dam to the crash of an
aircraft.
Though they might seem very different, both are complex engineering
structures with the capacity to wipe out suddenly hundreds of people.
Clearly with an aircraft it is necessary to have a comprehensive
system of
checks that keeps risks to an absolute minimum. The public demands
that.
And part of that system too is to have an exhaustive inquiry to
determine
the cause. It should be the same for dams.
On Waitangi Day in 1997 the Opuha Dam, under construction in South
Canterbury New Zealand, collapsed during a flood. Since then the dam
has
been completed, but there have been a series of court actions, many of
them
not yet resolved. Even when they are I am concerned that important
issues
will not have been addressed and there will remain a danger that
future
large dams could fail.
In my experience, when dams fail in developed countries overseas,
there is
more or less inevitably an inquiry, but in New Zealand at present,
despite
a dam's potential to cause such immense damage, this does not seem to
be
the case. It is the policy of the Government here now to let the
market
sort it out’ and this results in a plethora of costly, long winded
court
actions which in my view may not resolve all the issues. The only way
for
there to be a powerful inquiry here now, it seems, is for there to be
loss
of life, and the impact of big news. This is not good enough. Though
there
was no loss of life at Opuha, this was fortuitous, and farmers in the
region have told me that some people only just managed to get out of
the
way of the rampaging flood in time.
It is somewhat incidental that in the court action by the Canterbury
Regional Council (CRC) against DHL (the contractor), and Christopher
Hollingham (DHL's Project Manager), the judge said Hollingham was in a
significant position of responsibility for which he had no
qualification or
experience. This was his first dam. Though this was a serious matter
the
real issue was how such a situation could have arisen, and how to
prevent
it happening in the future.
Had the former Ministry of Works still been in existence, it would
undoubtedly have ensured that there was no failure at Opuha. In the
court
case mentioned above past President of the Institution of Professional
Engineers NZ (IPENZ), John Blakeley, said it appeared something was
wrong
in quality control. The fact was something was not provided for and
the
most obvious thing missing is that there was no one there to blow the
whistle. While the Ministry of Works would have monitored past
projects
quality control was now a grey area.
The Ministry of Works would also have been involved in the design and
Resource Management Act hearing stages. There is no doubt in my mind
that
this would have ensured that design and construction risks would have
been
much better provided for.
The NZ Government has, at present, no engineers at all with any of the
skills and experience of local conditions necessary to provide it with
independent advice in this field, so that prospects for any change and
proper vetting of future projects are not good. Private consulting
engineers are unlikely to push the issue, and the media have lost
interest.
These are the reasons why I, and many of my engineering colleagues,
are
extremely concerned that the lessons of the Opuha collapse have not
been
learnt. The irony is that it was once not this way. Sometimes the
wheel has
to be reinvented.
