This is the third part in a four-part series that discusses issues about water in our region. Read part 1 here. Read part 2 here. Part four asks how climate change will affect our region’s water security. 

NQCC hosted a forum about the Hell’s Gate Dam feasibility study currently being conducted by Townsville Enterprise Ltd. NQCC was grateful to have the on-hand expertise of Patricia O’Callaghan (TEL CEO), David Lynch (principal economist for the study) and Jon Brodie (waterways expert). Here is what we were told about the dam and the study, plus questions that came from the audience.

David’s presentation

The National Water Infrastructure Development Fund allocated $2.2 million of Federal funding to assess the feasibility of a dam at Hell’s Gate, which is about 50km inland from Paluma Dam (see map). This isn’t the first feasibility study to be conducted – the idea has been thrown around since the 1930s. Many other water feasibility studies are being conducted around the country – see the whole list here.

The study is organised into three phases – 1) agricultural development available from irrigation, 2) supplementing Townsville’s urban water supply, and 3) both agriculture and urban water.

It is believed that the irrigation made possible by the dam could provide 49,000 Ha of arable land. Here a few scenarios have been developed. Firstly, producing 4 million tons of sugar per annum, comprised of 400,000 tonnes of raw sugar and 100 million litres of ethanol. David said this scenario isn’t feasible in both terms of capital and operational expenditure. This was investigated in the 2014 North and Northwest Queensland Sustainable Resources Feasibility Studies. A second scenario, of 10 million tons per annum, could be reasonably viable with the right mix of raw sugar, ethanol and bagasse. Details within the 2014 Feasibility Study say that the required capital expenditure for the 4 mtpa scenario is $2.7 billion, and $4.9 billion for the 10 mtpa scale. “This investment is forecast to be commercially viable only in circumstances of high prices for the output sugar and ethanol and current policy settings.” “The social cost benefit analysis does not provide a positive forecast for the 4 mtpa case and emphasises the importance of larger operations to achieve economies of scale.”

Patricia said that while other projects like the Urannah Dam has proponents backing the project, there are no proposals or proponents for Hell’s Gate at this stage -“The feasibility study is to inform on an opportunity.” Questions arise about if it is financially viable and who, if anyone, will pay.

Questions to David:

Vern: The biggest cost is buying the allocation from Sunwater. Gravity-fed is cheaper, but not possible. It’s astounding that it would be considered given the height of over 500m, and the need to upgrade infrastructure all the way from Paluma Dam. Response from David began with that some engineers say that it can be gravity fed, audience members then pointed out the water would have over 500m uphill to travel, then it was agreed that Hell’s Gate cannot be gravity fed.

Jeanie: How have the traditional owners and native title holders been involved? Response from David was that they didn’t know, however this is included in the terms of reference of the study, and TEL will identify who is interested and what opportunities there are.

Gail: Can NQCC be involved in the terms of reference? Response from David was that yes, we can be, when the study goes to market. At the current moment NQCC cannot be involved but we can be provided with a list of the considerations in the terms of reference, including the Reef 2050 impacts. (Note: not yet supplied to NQCC).

Jon’s presentation

Jon Brodie began by saying that Hell’s Gate was ‘not the worst idea that has been put forward’ on the topic of dams in North Queensland.

Dams can trap sediment, so sediment flowing downstream into the Great Barrier Reef could be reduced in a river system that is dammed. However, less sand is carried downstream that would eventually replenish the beaches. Fine particles – mud – are not trapped by dams, or not so much, so muddy run-off from agriculture means more mud at the river mouth even with dams in between. Nutrients from sugar farming are a concern though because they would pass through a dam into the ocean. Any agricultural venture should be managed as per best practice. Another environmental issue that was mentioned was that the usually clear dry season flow of the Burdekin would be turned muddy.

The biggest concern of the project was identified as the impact of the agricultural expansion made possible by irrigation from the dam, not the dam in isolation. The bushland surrounding the potential dam site was deemed “not pristine but not bad”. NQCC believes this is an important point raised, with the issue of land clearing being such a major campaign this year. As it stands, the relaxed Newman-era clearing laws remain, however a Government committed to protecting the Reef and achieving climate action targets must reform land clearing legislation.

Questions to Jon:

Christy: What are the sediment risks? Jon responded saying that the risk to the Reef is reduced because the dam traps sediment. The dam will be turbid from the suspended particulate.

George: Is the ethanol for cars? David responded saying yes, it is for domestic Queensland use for cars. This is in line with the E10 component of fuels in the Biofuels Mandate. Then George also commented that if cars are the big reason for ethanol production, then this is surely a sunset industry with cars heading rapidly towards electric power.

George: Dams produce methane – will this be factored into environmental impact assessments? Jon responded that humid Burdekin conditions aren’t right for the rotting vegetation that causes runaway methane emissions found in other dam systems elsewhere.

David K: raised the concerns of the environmental impact – obliterating hectares of country – land clearing issues, and how this water would supply Townsville. Gail responded backing up earlier claims that this is emergency water only but it helps the case progress forward by gaining citizens support.

Wendy: Are you going to be unbiased? Patricia responded saying yes, the results of the study are independently reviewed, there will be a high level of scrutiny, they are conducting a fact finding mission with a neutral stance and employing an independent economist

Rocco: raised the consideration of Water Quality Improvement Plansand the risk of increased nitrogen from irrigated sugar. Jon responded saying the 2050 targets are nonsense and is hopeful that the potential nitrogen pollution arising from intensive sugar cane agriculture is assessed in the study.