What’s so wrong with a dam on the Mary River at Traveston Crossing?
Not a solution to South East Queensland ‘water crisis’.
If built, this dam would not be able to supply water until 2012 at the earliest. Brisbane’s current water shortage needs to be solved by 2008 and there are viable alternatives that can come in to effect in this time frame. In the longer term, the projected demand for water to feed continued unsustainable growth in SE Qld simply cannot be met by building more ineffective dams in the south east corner.
Socially destructive and inequitable on an unprecedented scale.
The dam proposal involves the forced resumption of ‘potentially more than 1000 freehold properties in closely-knit communities of the Mary Valley and the loss or relocation of all public infrastructure in the area. The dam footprint covers 77 square km (far larger than the electorates of Central and South Brisbane combined) of fertile, irrigated farmland, close to transport and population centres, which is a far more important resource for future generations than fresh water alone. The loss of these properties has negative flow-on economic effects on the businesses that service the region, and will also cause a number of these to leave the area.
The Mary catchment is the main source of water for Gympie to Hervey Bay and all the shires, towns and cities downstream of the dam.
Wasting precious water by storing it in an inefficient, shallow dam and redirecting large amounts of what remains out of the catchment to Brisbane steals water from downstream communities, impacting on a geographical area greater than the Pine, Brisbane, Ipswich, Logan, Redlands, Gold Coast and Tweed Shires combined. No compensation has been offered to downstream communities for this loss of water. The commercial fishing and tourism industries of the great Sandy Straits are also threatened by negative impacts of reduced river flows. It would be hard to find another single infrastructure decision in Australia’s history that has such a deliberate and directly negative social impact on as many people as this proposal.
Ridiculously expensive water for South East Queensland
The dam proposal was originally based on a flawed economic analysis of annual yield of 160 GL (billion litres), no allowance for environmental flows and a total cost estimate of $850 million. The latest official cost estimates have risen to more than $1.7 billion for a stage one yield of only 70 GL per year. This is considerably more expensive than other water supply options, including the Tugan desalination plant ($850 million for 45GL per year). The government still cannot give an answer on the full extent of properties that need to be resumed and infrastructure that will be affected, and so it can be expected that the costs will continue to rise. Under the government’s incoming scheme of fully tradable, privately-owned water allocations distributed via a corporately controlled water grid this proposal would result in very expensive water at the tap in Brisbane households.
A willful act of environmental vandalism with global implications.
Fraught with many unsolved technical difficulties.
The dam site is on the alluvial floodplain of the Mary River, on very flat land, with very deep, fertile, well-farmed soils. This makes for a very shallow pondage, prone to extraordinarily high seepage and evaporation losses and subject to serious water quality problems of high nutrient loads, low oxygen, toxic metal contamination, algae and weed infestation, greenhouse gas production and sedimentation. If 
constructed, at stage one it will have an average depth of only approximately 6m, and at stage two an average depth of about 8m. Much of the dam would be less than 2m deep. At the proposed dam site, most of the water flows in brief flood events, and most of the time there is very little flow. This causes considerable trouble with designing a spillway that can handle the large flood flows and the flat nature of the terrain means that allowing for the effect of these flows results in flooding a large additional area of land upstream from the dam outside the normal storage level. This combination also causes considerable structural problems with river bank stability and erosion downstream of the dam.
No solution has yet been announced for how the river will be safely diverted while construction occurs. The dam site overlays a region of deep shattered rock which needs to be sealed by drilling it and pumping it with concrete to stop seepage. As well as being very expensive, this will seriously interfere with groundwater flows in the valley. The full implications of this on the dam and the valley downstream have not been studied. These technical difficulties contribute to the huge initial cost of the project, but also will contribute to very high ongoing running and maintenance costs.
Appalling lack of consultation within government and with the public.
public consultation process in the preparation of the Mary Basin Water Resource Plan. Anecdotal evidence suggests that local state government officers had no knowledge of the dam proposal up to the time of the Premier’s announcement. For example, the Main Roads department had just called for tenders to replace a bridge on the Mary River that will be flooded, and were unaware that the dam proposal would require the re-location of the Bruce Highway!
Symptomatic of a failure of democracy within Queensland politics.
Who stands to benefit financially from this dam?
This is an important question. Obviously the companies and unions involved in the construction of a $1.7
billion project have a direct interest in the project going ahead. Who are the main players in these companies? Is the funding of this project still linked to the sale of the retail operations of Energex and Ergon as initially announced by the Premier? Which companies are negotiating to buy these operations? What is the economic and corporate link between the power grid and the water grid? A major change in water commerce in Queensland is the introduction of fully tradable water allocations. This means that water entitlements from Queensland water resources will no longer be linked to property titles, but will be registered in a separate title register, and will be able to be freely traded by brokers. The introduction of a water grid enables these allocations to be freely traded between catchments and allocation owners. The creation of a major saleable new water resource close to Queensland’s largest water market on the cusp of the introduction of this new trading system would probably be seen as a commercial opportunity by some astute investors. Who are they?
Are there any viable alternatives to this dam proposal?
There are many viable options already identified by the State Government and some of these are listed in the Queensland Government report “Water for South East Queensland – a long term solution” published in June 2006. (All the yield and cost statistics used in this document come from that report). The obvious strategies in that report like demand reduction, compulsory use of rainwater tanks on all new developments, greywater re-use, reducing reticulation losses and industrial re-use have not been implemented, and yet current world best practice suggests that these strategies should be in place before a Government even considers the prospect of building expensive, inefficient and destructive new dams. Some of the other options available, such as groundwater extraction from the coastal plain north of Brisbane are yet to be adequately investigated, but have the potential to make significant contributions. (For example, Perth gets approximately 80% of its water from groundwater extraction from its coastal plain, and only 20% from dams).
The most obvious source of water is the greater Brisbane area itself – more than 1000 GL of fresh water is discharged from the Brisbane River each year (remember that the Traveston Crossing dam would only provide 70GL per year in stage one). Re-using a small proportion of the fresh water discharge from the Brisbane metropolitan catchment into Moreton Bay is far more accessible to Brisbane than the Traveston Crossing dam, and would have positive environmental benefits for Moreton Bay and the Mary Catchment- a win-win solution on all fronts.
Even the Tugan desalination plant (with current relatively inefficient technology) will provides water at a lower price than the proposed dam on current Government figures. There may be scope for many other innovative technical options, but the main solution needs to come from rational long-term planning and recognizing that unchecked continual growth in the taking of fresh water from the natural environment is simply impossible to satisfy in the medium and long terms. Re-allocating water from the environment further and further afield to avoid facing up to this reality is also unsustainable. The beauty of water is that it is the ultimate re-usable and recyclable resource – we should face the challenge of treating it as such.
How can you act for a better outcome?
Pass this information on to other people, think about the issue, check out the facts for yourself, email this page to a friend, lobby your local State and Federal member, exercise your rights at the ballot box. Start by investigating these sources of information.
Save The Mary River Co-ordinating Group www.savethemaryriver.com Detailed information and downloadable resources
Online Forum www.savethemaryriver.com/forum 5000+ posts and lastest public comment in a searchable database