A recent report in USA Today highlighted the risks associated with over abstraction
of groundwater around the world.
Interestingly, the report didn’t mention New Zealand. Maybe because the
scale of some of the areas they’re talking about is far larger than the whole
of New Zealand –India, for example.
Now I’m not a ground water
hydrologist and don’t pretend to know much about the subject. However, it stands to reason that all
resources are limited - oil, gas, groundwater. It’s a really simple mathematical equation; if
we extract more than can be recharged, eventually we will run out. It’s that simple. Determining how much is recharged and how
much will be recharged as climate change hits
is way beyond me - but I think
it’s safe to say that if we’re losing now, things aren’t going to get any
better as the climate changes.
So what should we do to meet
the current needs? We can’t just stop pumping, can we? Well, in some places in the world they’ve had
to – there’s nothing left to pump. This
is a bad position and we don’t want to get there. But we can’t stop pumping and
neither should we, but that pumping must be at a rate that doesn’t exceed what’s
Given that our demand for both
potable and irrigation water is ever increasing, we need to look at alternative
sources. Invariably those sources are
either socially or environmentally unacceptable, or in the wrong place, or all
I arrived in New Zealand in
1999 and at that time there was a proposal being considered to take water from
the outlet of Manapouri in Milford Sound and tanker it by ship to the Middle
East. I believe such projects have been
proposed on and off for decades. These
proposals are generally rejected because we don’t want hordes of huge tankers
going in and out of Milford Sound with the risk of an accident causing an
In Auckland, there’s a river
of about 300 million litres per day that just flows out into the Manukau
Harbour – the effluent from the Mangere wastewater treatment plant. No matter how well we treat this, the public
perception is that it’s sewage. It is
In Canterbury, there have
been all sorts of ideas about how water could be harvested on the West Coast
and transferred over the mountains.
We need to look at
non-traditional methods of harvesting water and start thinking of ideas that,
although they might have been rejected in the past as unworkable or too risky,
are worth pursuing.
What I’m saying is that
something needs to give – either the extremely low tolerance to environmental
risk or the social acceptance of alternative water sources. We can’t continue with our prejudices and
zero risk approach to the environment if we wish to meet the needs of the
present without compromising the ability of future generations to meet their
This thought leadership article by Iain Rabbitts, a water and wastewater manager in our water resources team, is intended to provide you with insights and relevant information on the risks of over abstracting groundwater. Our thought leadership articles on topical and specialist issues are designed to present the key points in an easy to digest and interesting manner.
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