Thursday, January 20, 2011

To build or not to build a dam –that is the question

The proposed Traveston dam on the Mary River was always considered controversial. When the Rudd Government environment minister, Peter Garrett blocked the building of the dam, the people in the region were quite happy. The Queensland Premier, Anna Bligh did not attempt to protest the blocking of the dam but instead she decided to take the route of building a desalinisation plant.  The question to be asked right now, though, is whether or not the blocking of the dam, in light of the floods experienced last year and again this year, made matters worse for the flooding of Brisbane.

First of all,  here is a little bit of perspective regarding the region under discussion and how it relates to Brisbane:




As you can see from the map, Maryborough is to the north of Brisbane, and below Rockhampton, Hervey Bay and Bundaberg. Toowoomba is to the west of Brisbane.

During December the Fitzroy river, which flows through Rockhampton was in flood, and it was the same in early January.  From this map we should be able to trace the flow of the waters from the Fitzroy River, and into the Wivenhoe dam.  The rains in this region had been heavy since at least September 2010, which in effect explains why the Wivenhoe dam had reached capacity.

Now let us look at the reasons that Garrett rejected the building of a dam on the Mary River. Keep in mind that the residents were against the building of the dam (which is natural since they would have been displaced). However, the reason for the decision was based upon the fact that three endangered species that rely upon the Mary River would have been displaced. These species are: the Australian lung fish, the Mary River turtle, and the Mary River cod. The building of the dam would have destroyed the natural habitat of these species.  However, Garrett did not base his decision to ban the dam on the impact of these species, but he based it upon a report from the Centre for International Economics which came to the conclusion that the decision by the Queensland Government to go ahead and build the dam was based upon flawed data.

If the project had been given the go ahead, then the dam would have been able to supply 70,000 megalitres of water to the Brisbane population.  It might or might not helped in the mitigation of the flood damage that was experienced in the towns south of Maryborough.

Since this was a recent project, there is doubt that had the dam being given approval to go ahead that it would have been finished in time, or at least prior to the rains brought by the La Nina.  The point is that even if the building of this dam was blocked, the Queensland government then did nothing to seek out alternative spots to build a dam, and instead chose to go ahead and build 4 desalination plants that have now been mothballed.

On top of that, I suspect that decisions were being made based upon the belief that “climate change” meant that Queensland would never see again the floods of the past. The Wivenhoe dam was built after the floods of 1974, and it was supposed to stop a similar kind of devastating flood from happening again.  There are plenty of questions to be asked about how the operators of the Wivenhoe dam were releasing water in the week prior to the devastating floods.  It is not so much the banning of the Traveston dam on the Mary River that helped to cause the situation, but the operation of the Wivenhoe that needs to be examined in some detail. Also, what needs to be questioned is why did the Queensland government fail to seek other alternative sites for a dam, sites that would have been more viable than the proposed Traveston, and sites that did not involve damaging the habitat of endangered species.

No comments: