Monthly Archives: September 2007

This is a fait accompli. Then the Queensland government plans to model the Island’s hydrological system and use an adaptive management strategy to manage the resource given that the model is verified and works. The plan states that it may take up to 2 years to verify the model.

This process puts the cart before the horse.It is at odds with the precautionary principle that a development or a new technology should not be undertaken before the likely consequences are known. Specific comments related to this water plan. There are limitations with the data including:

• Lack of access to mining company water pumping records to verify data.
• Significant error band in current estimates eg. p24 – the long term recharge of the aquifer of 400 – 800mm/yr of rainfall
• Selected use of rainfall data from the Bureau of Meteorology (BOM) Eg. 1960 to 1999 rather than the full record including the current drought.

The likely effects of climate change are glossed over. BOM data already shows an east coast receiving about 40 to 50mm less rainfall every 10 years since 1950. Some rainfall data over the past 20 years from The Gap shows a much higher rate of rainfall decline at that location.Tim Flannery in his book, “The Weathermakers” states that complex systems such as climate do not change in a perfect progressive linear way.

Instead they often change abruptly (relatively speaking) as they shift to another set of complex conditions (Flannery, p.83).

Climate data indicates that there appears to have been step changes in the climate in 1976 and 1998. Each of these shifts is likely to change the boundaries of daily weather and so extremes events become more common and more extreme.

Several ecological indicators of this region already tell us to tread carefully. For example, the water quality of Moreton Bay and streams feeding the bay are in decline (refer to Qld. EPA’s Healthy Waterways Ecosystem Report Cards at www.healthywaterways.org).

The plan states that there has been a steady decline in the water table level of NSI (p.29) and that there is a link between water taken from NSI, water table levels and ecosystem health (p.29).

Ecosystems include weather systems and respond as complex systems.

Graph taken from (Factor Four, Weizsacker p.236)

Weizsacker has demonstrated the effects of acid rain on the health of a North American lake . He shows that pollution added to an environment may have little measurable effect for many years before the ecosystem quite rapidly declines, in this case as the acidity as measured by decreasing pH rapidly started to increase around 1950.

This is an example of a tipping point being reached when complex systems rapidly change to a new set of conditions.Finally there are the limitations of the existing steady state computer model of the NSI hydrological system.

While the current model may be able to closely replicate water levels observed in most NRW bores, the plan lists the limitations of the model with regard to the risk of sea water intrusion. Hence a new model is being built to “simulate water table fluctuations under prolonged wet or dry conditions” (p.25).

Surely the model should be proven before it is used for decision making.Ultimately the debate comes down to what is the sustainable carrying capacity of the SE Queensland region in terms of human population and resource extraction, use and waste generation, before ecosystems go into serious decline and more and more resources have to be imported.

Environmental scientists argue that in the final analysis, populations have to live within the carrying capacity of the Earth and preferably of their regions.

We have already exceeded globally the available arable land area per person. (Nielsen, p. 239) as the population continues to explode at 80 million per year (Nielsen, p.19).

According to Graymore, for SE Queensland with the current per capita resource consumption (not just water), the overall sustainable carrying capacity is about 362,000 people.

Many resources can be imported but not necessarily sustainably.Desalination, bringing large icebergs of fresh water from Antarctica, or piping water from the far north are all offered as solutions to SE Queensland’s water problems.

These solutions could in the longer term minimise the necessity to extract more water from North Stradbroke Island.

All these proposals are energy intensive, expensive and may lead to further complex environmental problems eg. changing the salinity of the oceans.

In an economic system based on a fictional belief in infinite resources and waste sinks, exponential growth of population, resource consumption and waste generation, the ocean will simply be treated as an infinite resource and waste depository.

I doubt if these simplistic fixes are ecologically sustainable.In my opinion, the long term solution lies in learning to live within the ecological limits of a region including its fresh water supply.

This limit is set by our catchment area, allowing for ecological flows to maintain natural habitat. We seem to be hell bent on exceeding this limit.Trevor Berrill September, 2007.

References

Flannery, T. (2005). The Weather Makers. Text Publishing Ltd.Graymore, M. (2001).

The Ecological Footprint of SEQ 2000-01. Coastal CRC, Griffith Uni.Weizsacker et al (1997).

Factor 4: Doubling wealth – halving resource use. Club of Rome.