By Glenis Green
July 01, 2006


LABELLED a social and environmental disaster by critics two months ago when first announced, the proposed Traveston mega-dam on the Mary River near Gympie is now shaping up as a political disaster for the State Government.

And if you speak to some of the structural experts who are siding with the burgeoning group of protesters, the $150 million dam will also be an engineering disaster.

Apart from the emotion, environmental and financial impact, personal hardship and relocation of communities, evidence is mounting that the dam simply will not work.

According to University of Queensland Associate Professor of Geomechanics David Williams, the proposed dam’s surface area is too big, the dam will be too shallow and its alluvial base means it will leak. Other opponents, such as Traveston Crossing graziers Rick and Carol Elliot, describe it less euphemistically as “a huge, stinking, putrid swamp of weeds”, while Wide Bay federal MP Warren Truss describes it as “a dud”.

“Experts say the dam will not hold water and will evaporate twice as fast as other options,” he says.

“Drilling tests seem to confirm that the foundations cannot support the dam wall.”

With evaporation, seepage, sedimentation, leakage and spare capacity for flood mitigation as promised by the State Government, some water experts say there simply would not be enough left over for the annual water yield the Government hopes to take out for Brisbane consumers.

In arguing his point for the Save The Mary River Co-ordination Group, Williams says it is doubtful the proposed dam would hold a fraction of its intended 660,000 megalitre capacity.

“If you look at dams around the world, most are built in mountainous terrain because you can find solid rock and achieve a small surface area, greatly reducing seepage, foundation and evaporation problems,” he says. “Putting a major dam in a shallow basin underlaid with alluvium is not what we normally do.”

Williams says the Traveston area is a large catchment, but it is also a very flat valley spreading over more than 76sq km, meaning the dam’s average depth would be just 8.6m, which would be reduced by about 1.42m a year by evaporation, according to Bureau of Meteorology figures.

Seepage through the base, dependent on the foundation, could be up to 3m a year and the predicted withdrawal for water needs would be about 150,000 megalitres annually.

“Add in the long-term effects of sediment build-up in the dam and it may not even be able to supply the allocation they want, let alone anything for other water-users in the region,” Williams says.

While dams do not need a solid bedrock for a foundation, a dam built on sediment would probably need a grout curtain, adding to its costs.

Williams’ observations have been backed by Noosa Council’s works manager and Save The Mary group secretary Alan Sheridan, who has condemned the site as “a political solution”.

“Damning a river mid-stream on an alluvial flood plain just does not make sense,” he says.

With the Government apparently stalling the release of its own engineering report on the site – promised for this week but now put off until at least the next parliamentary sittings on July 11 – the scientific arguments put forward by Williams and Sheridan have been embraced by anti-dam campaigners.

Residents question why the Government wants to press ahead with a dam which will flood some of the state’s most productive agricultural land, threaten vulnerable fish, frog, bird and butterfly species, affect the Great Sandy World Heritage area downstream, flood cemeteries, schools, established roads and parts of small towns and mean community upheaval.

There is also the potential hazard of up to 200 arsenic cattle dips being flooded, along with salinity problems which just three years ago prompted the Department of Natural Resources and Mines to advise landowners to avoid building dams in some areas in the valley.

Opponents point out that the Government ruled the same site unsuitable in a 1994 report on Mary River Valley water supply sources because of “high capital cost, inundation of prime agricultural land and displacement of rural population”.

The Government’s preferred strategy then included the progressive raising of Borumba Dam near Imbil, a regulating weir at Moy Pocket near Kenilworth, raising the wall of Lenthall’s Dam on the Burrum River as well as a reduction of demand through use of urban rainwater tanks and treated wastewater and a longer-term strategy for a dam at Amamoor.

Land had already been bought around Borumba Dam and Amamoor before Premier Peter Beattie announced the Traveston site on April 27.

Elliot, who has been spearheading anti-dam campaigning in the Mary Valley, says during the past 10 years almost $40 million has been spent acquiring some 12,000 ha of land for four proposed dams – at Wyaralong, Glendower, Amamoor Creek and Borumba Dam, stage three.

“It would seem reasonable to ask why none of these projects has been progressed and why we have had to wait for a critical water storage to come up with a totally new and previously unsupported dam proposal,” he said.

If the plethora of anti-dam signs along the highway from Federal to Gympie in the past two months are a sign of the times, then Beattie might have made a decision which could rival former Labor premier Wayne Goss’s infamous “Koala Road” which cost him government in the 1990s.

The confusion surrounding the final dam decision is taking its toll on some 900 families and businesses which will be directly affected, and there’s a growing resentment they are being disadvantaged to bolster Beattie’s standing in water-hungry metropolitan seats.

Much of the Mary Valley falls in controversial Independent MP Elisa Roberts’ electorate, which also borders the electorates of fellow Independents Chris Foley in Maryborough and Peter Wellington in Nicklin.

Wellington, a member of the new dam impact committee set up by Beattie during Parliament’s past sittings, and which has yet to meet, cautions that while the Government is taking “a very strong line” on the Traveston site, final engineering reports are yet to be presented. “There’s the reality if the geotechnical information does not stack up, it simply cannot be built  ,” Wellington says.

Deputy chairman on the new dam impact committee is Noosa’s controversial Labor MP Cate Molloy, who has lost party endorsement after her opposition to the dam. With Molloy disendorsed and planning to stand as an Independent at the next election, the committee does not have a Labor majority.

Led by Water Minister Henry Palaszczuk, it also comprises Glass House Labor MP Carolyn Male, Hervey Bay Labor MP Andrew McNamara and then Foley, Roberts, Wellington and Molloy – meaning the Independents appear to have the final say on what recommendations will be forwarded to the Federal Government.

The unknown factor will be the independent community guardian – promised but yet to be appointed by Beattie – who will liaise with committee members to ensure all local issues of concern are heard.

While Palaszczuk and Beattie have said the Traveston Dam is “locked in”, it is apparent the final tick has to be given by the Federal Government, which also could find that the state’s actions on the dam site have breached federal law – particularly the Federal Environmental Protection and Biodiversity Conservation Act.

Some cynics are even saying that Beattie will use the dam impact committee’s findings and any Federal Government opposition as an escape hatch to perform one of his famous backflips and thus save face over the whole dam mess.

Truss says that despite Beattie’s insistence “the dam will be built no matter what”, it is becoming increasingly obvious it should not.

“The evidence is continuing to mount in support of local views that the dam would be a social, economic, environmental and aesthetic disaster,” Truss says, pointing out the State Government’s advisers have admitted Traveston is only the fourth-best site.

“It is time the Queensland Government acknowledged the reality that their desperate, ill-considered Traveston Dam is a dud,” he says. “They should accept the justified humiliation of their incompetent management of this plan and let local people get back to their lives.”

Yesterday, a spokesman for Palaszczuk said Traveston was “the preferred site of the Government and we want it to go ahead” and that the final engineering reports would be released during Parliament’s next sittings when “the final OK” would be made in Cabinet.

Minister’s response

Henry Palaszczuk, Minister for Natural Resources, Mines and Water, replies:

On the suggestion that the dam will be too shallow and its alluvial base means it will leak.

“The Traveston dam site in the Mary River catchment has been identified as the largest yielding potential new water storage in southeast Queensland. The site has been identified for further assessment based on its capacity to deliver very large quantities of reliable water compared with other potential sites throughout southeast Queensland.

“Preliminary studies indicate that the storage could hold as much as 660,000 megalitres and deliver approximately 150,000 megalitres per annum.

“The Department of Natural Resources, Mines and Water has the ability to check rainfall back to 1890. The department advises that the rainfall and river flow data supports its recommendation to Government to investigate the Traveston site.”

On Wide Bay Federal MP Warren Truss describing the Mary River dam proposal as “a dud”.

“The drilling program is designed to build a geological picture of the site which will determine the appropriate form of construction for the dam wall. Definitive results will not be known until after the analysis is completed. Mr Truss should bring his concerns with the proposed Traveston dam to the attention of the Queensland Government rather than just making statements to the media … The final go-ahead is dependent on various Commonwealth and State Government approvals, which are still required.

“On-ground geotechnical assessments and other assessments all need to be completed before these approvals can be obtained but Traveston is the Queensland Government’s preferred site.”

On the fact that the Government itself ruled the same site unsuitable in a 1994 report on Mary River Valley water supply sources because of “high capital cost, inundation of prime agricultural land and displacement of rural population”.

“In 1994, the Department of Primary Industries conducted a study of water supply sources for the Sunshine Coast and Mary River Valley only. The Government has since identified a need for establishing a regional water storage, capable of supplying water to all of southeast Queensland. The current investigation of the Traveston dam site is the most comprehensive ever undertaken. These studies will … build on previous investigations.”

Alan Sheridans comments