It is ''irrational'' to exempt dams built before national
building standards from proposed dam safety regulations, the
Otago Regional Council says.
The council, along with Environment Canterbury and Waikato
Regional Council, is calling for the Ministry of Business,
Innovation and Employment to reconsider its proposed
regulations for dam safety.
The Otago Regional Council has been pushing for a large dam
to be defined by its height ''or'' its volume, rather than
both height ''and'' volume thresholds.
Otago Regional Council environmental engineering and natural
hazards director Gavin Palmer said despite previously
advising support for changing ''and'' to ''or'' in the
definition of a large dam on the grounds of safety risks, the
department had approved a supplementary order paper
recommending leaving the definition unchanged.
''We strongly believe in a risk-based approach to dam safety
and to minimise compliance costs.''
The paper is to be tabled during the third reading of the
Building Amendment Bill No 4 and the finalised regulations
are to take effect on July 1 next year.
Dr Palmer, who wrote a submission paper on behalf of the
three councils, did not believe the changes achieved the end
purpose of ensuring high-risk dams were managed.
The changes created a separation between building controls
for dams and obligations under dam safety regulations, and
If dams had to meet safety obligations, why would they not
have to meet construction standards, he said.
''That is the irrational aspect. It should be both or
Experience had shown it was difficult to retrospectively make
a dam code-compliant, so it made sense to make sure it was
compliant from the start, he said.
There were also concerns around the populated 1km
''designated area'' around a dam which would trigger safety
The council believed there were effects well beyond 1km in
An example was a snow-making dam on the side of a mountain
which did not have a population within 1km, but a breach
would effect the downstream population and environment beyond
It would not be until the legislation came into force the
true extent of dams in New Zealand would be known.
Chairman Stephen Woodhead said at a meeting this month there
appeared to be an element of the irrigation industry pushing
back the other way.
Irrigation New Zealand chief executive Andrew Currie said
some of the thresholds being called for by the likes of the
ORC were ''over the top''.
There were many dams in Canterbury and some in Otago which
were on flat land and controlled by an intake fed by an
irrigation scheme that would be captured by those rules.
Other dams were in the middle of nowhere and, if they failed,
would only flood landowners' own land.
That translated into extra costs for landowners for no
No-one had appeared to have done a cost-benefit analysis on
the proposals, he said.