Traveston Crossing Dam

I recently completed a grueling four week journey up the Brisbane River, through Wivenhoe and Somerset Dams, over the Conondale Ranges, down the Mary River, Great Sandy Strait and back to Brisbane via the Pacific Ocean. The trip was in a wheeled kayak so it allowed plenty of time to look at the river systems and the actions of government.

There are four strategic observations that I wish to comment on. These are within the scope of my professional knowledge and are additional to anything that professionals in the fields of threatened species have to say.

1. The Brisbane River is dysfunctional as a river. Government departments argue with each other about whose fault it is. They all say it is the landowners’ responsibility but the fact remains that many kilometres of the river are hidden under a mass of water hyacinth. This weed not only destroys all other life in the area, it uses vast amounts of additional water. How can we trust anyone who says that they know what they are doing with damming the Mary River when this is what they have done already?
  Brisbane River
Brisbane River near Fernvale - April 2008
2. Traveston Crossing Dam will be less than 2m deep over a great percentage of its area. Evaporation is somewhere between 1.5 and 2m per annum. Wivenhoe dam is not a deep dam and suffers similarly from significant greenhouse gas generation. The longer the water level is low between fills, the more vegetation regeneration occurs. There is no escaping the fact that on an average annual basis large volumes of methane are produced when this vegetation rots. Methane is more than twenty times more powerful as a greenhouse gas than CO2.
Vegetation regenaration and methane
Wivenhoe revegetation being flooded
3. The Mary River catchment and the Somerset Dam catchment are subjected to similar vagaries of weather patterns. They touch each other. They are both behind coastal ranges. The only difference is one runs north, the other south, from where they meet.
Fall between Mary River & Somerset Dam
Right foot flows to Somerset Dam, left foot to Mary catchment
4. The influence of the Mary River on marine life in Great Sandy Strait is striking. Marine life is abundant near where the Mary is but decreases as you get away from that area.
Looks closely. A sea turtle
Look closely. I thought the turtle was a rock

The Queensland Water Commission has released its draft SEQ Water Strategy. It contains no discussion on any of the above issues. Quite frankly I find it an insult to my intelligence. I also find it deeply disturbing that water professionals in Queensland have accepted what the Commission has said.

There are many other issues that I have not canvassed. Many professional people have questioned the hydrologic analysis and the only answer they get is “Trust us, we know what we are doing.” The effect of climate change on the efficacy of the dam will only be reviewed after the dam is being built.

Peak oil is a fact, not a theory. Like it or not we are about to experience some very nasty effects. The government’s own McNamara Report states that arable land close to population centres is crucial. This dam takes much productive land away. Couple this with the fact that the Lockyer Valley has been mining water for decades and in many places the mine has almost run out. So we lose one area due to overuse and flood the other.

This issue is of national importance. It is far more important than the Franklin Dam but it is not on the national agenda. Perhaps this is because the land to be flooded does not look as spectacular as that on the Franklin. Perhaps it is due to the very clever and brutal spin by the Queensland government.

If this dam proceeds, history will judge the perpetrators very poorly. There are many much better alternatives such as:

1. Desalination with renewable energy
2. Extend water recycling to the whole of the water grid
3. Build infrastructure to capture and store the water that falls on Brisbane which is more than what Brisbane actually uses

These are my issues. They are my perspective based on more than three decades of work as a civil engineer in the water industry. As I have said there are many perspectives, not the least of which is the inability of the Queensland government to pass an audit on the Paradise Dam on the Burnett River to the north. The Lungfish, Mary River Turtle, and the Mary River Cod are all threatened by the dam.

Some academics are saying that the debate with the Queensland government has now moved from the rational to the irrational as they have been provided many rational arguments which have been completely stonewalled.


Steve Posselt
MIE Aust