Council votes on Mount Morgan water security preliminary evaluation

Rockhampton Regional Council has voted to progress with a pipeline from Gracemere to Mount Morgan as a long-term solution for the town’s ongoing water woes and a report has shown why all other options were struck out or short-listed. See why here.

All the possible options to fix Mount Morgan’s ongoing water woes in the long-term, including relocating the town, desilting the No.7 Dam or recycling effluent water, have been discussed at length, with the preliminary evaluation explaining why some of the options simply won’t work.

After more than an hour of discussion during Tuesday’s Rockhampton Regional Council meeting, councillors voted to proceed with the business case to find a long-term solution to the community’s ongoing water supply issues.

According to the council agenda for Tuesday’s meeting, the council officer’s preferred and recommended option for the long term solution was the construction of the Gracemere to Mount Morgan pipeline.

As a whole, this pipeline would cost $39,479,714 with about $22m estimated to be spent on construction alone.

The report was presented to council by AECOM associate director for water Janice Moody and team lead for water in Rockhampton, Abby Carolan.

As well as the preferred option, Ms Moody went through all other projects that were considered for the preliminary evaluation, with the report showing why they were struck out.

Water truck arriving at the Mount Morgan Water Treatment Plant. Picture: Contributed

Mayor Tony Williams said the report recommended the Gracemere to Mount Morgan pipeline was the most viable option going forward.

“A number of options were assessed as part of this process and the outcome was that the best, most economic option is for a potable water pipeline with a connection at Gracemere,” he said.

“We know the people of Mount Morgan have been wanting a pipeline for a long time, but we can’t just go out and build a pipeline; unfortunately it’s not that easy.

“We need to go through this process so we can partner with other levels of government in the future to gives us a better chance of receiving funding and the pipeline becoming a reality.

“We are doing this Preliminary Evaluation and subsequent Business Case because it is in line with the Queensland Treasury’s Project Assessment Framework – which is the key to justifying the project and seeking funding support from all levels of government.

“The Mount Morgan community have been battling a drought for far too long, and we want to make sure this is done the right way so they never, ever have to experience this again.”

Water and Environmental Sustainability portfolio spokeswoman Donna Kirkland said council was seeking support from other levels of government for the costs of water cartage and the next stages of the project.

“Council has already spent millions of dollars trucking water to Mount Morgan just so residents can turn on their taps,” Cr Kirkland said.

“While the State Government hasn’t provided any support for this so far, they have committed to looking at the situation again once the wet season is over.

Councillor Cherie Rutherford, Mayor Tony Williams and Councillor Donna Kirkland speaking about the Mount Morgan water issues.

“We also have an endorsed advocacy priority to seek $3.5 million for a business case and detailed design to get this project off the ground.

“The current estimate for the construction of a pipeline to Mount Morgan has been estimated at approximately $40 million, and we will be firming up costs through the business case and detailed design stages.

“It will be one year this month since the Mount Morgan community have been in Level 6 (emergency supply) restrictions.

“During this time, we have continued to cart water from Gracemere to Mount Morgan, which has cost Council around $4.5 million so far.

“We know that carting water is not a sustainable long term solution, both for Mount Morgan and the ratepayers of the Rockhampton region, which is why we are committed to finding a solution for the community of Mount Morgan that will continue to provide for many years to come.”

Divisional Councillor Cherie Rutherford said the endorsement was another important step in the journey for a long-term solution.

“The people of Mount Morgan have been through so much and we truly appreciate their patience while we work through this process together,” Cr Rutherford said.

“It is a credit to the Mount Morgan community how well they have done in the face of strict water restrictions. We know this is difficult, but it is so important that everyone comes together and this great work continues to conserve that carted water supply.

“The next step for the long-term solution is the business case. Council has committed $300,000 towards this already and we are seeking $500,000 from other levels of government to complete this work. From there, we estimate it will be another $3 million on top of that to get the detailed design done and this will give us the most complete picture of what the project will cost and how it will be delivered,” Cr Rutherford said.

Below are all options that were considered by AECOM and why they were struck out or short-listed.

Base Case 1: Do Nothing

Description: Continued trucking of water to Mount Morgan community in time of severe drought restrictions/drought, as per current practice. The baseline option provides a poor level of service and as such, the benefit of improved level of service, as proposed by the alternative options (and will be tested through technical evaluation), will be measured through subsequent economic analyses.

Will it work?: Potentially. Base case one looks at the council’s current situation, this option provides a “poor level of service” as per the other suggested options.

Base Case 2: Increased water carting

Description: Option BCO2 is similar to BC01 but considers an increased amount of trucking to enable lifting of restrictions. The configuration for this option would see water delivered directly to town reservoir or similar to current practice once the No. 7 dam hits the level three restriction trigger level of 30 per cent dam level.

Will it work?: Potentially. Base case two was brought in as an option if it is decided to continue trucking water. The increased water trucking would match the level of water supply other services could provide. Increased amounts would be 1.2ML a day.

Non Asset Solution 1: Operating Adjustment No. 7 Dam

Description: Option NA01 provides opportunity to adjust the restriction triggers and target demand presently in place on N0.7 dam to determine whether its reliability is improved in doing so.

Will it work?: No. Water balanced modelling showed limited improvement in reliability of the dam through adjustment of restrictions.

Non Asset Solution 2: Demand Reduction Strategies

Description: Demand management is the long term reduction in average water use by the community. It should not be confused with drought management, which requires a specific response to lowering source supply availability and can still be required even if long term demand reductions are achieved.

The benefit of demand management can be measured several way:

• By determining the frequency of restrictions incurred, given that lower demand is taken from the supply source overall.
• By determining the impact of infrastructure sizing as a result of lower demand. In some instances, negligible difference in infrastructure size, and hence capital spend, can be realised due to standardised sizing of infrastructure (e.g. set pipeline diameter) available on market. Savings may be achieved through operating costs.

Will it work?: No. Water balance modelling showed that no improvement in reliability of the dam through provision of long-term demand reductions.

Non Asset Solution 3: Relocate the town

Description: Option NA03 is another non-infrastructure scheme that considers the buyback of homes in the Mount Morgan district, to enable residents to relocate to Rockhampton/Gracemere where water reliability is higher.

Will it work?: No. This option was thrown into the options as a variable and is unlikely to eventuate. This option is unlikely acceptable to the community; there would also be substantial costs to acquire properties in comparison to other options.

Asset Solution 1: Augmentation of No. 7 Dam

Description: Option A01 involves raising of the dam crest and spillway height to address both the upcoming legislated dam safety requirements discussed above and increase storage volume concurrently. Previous assessments undertaken by council indicate that an additional volume of 200-300ML would be targeted however this would be subject to further hydrological and design assessment.

Will it work?: No. Water balance modelling showed that no improvement in reliability of the dam was achieved through raising the dam.

Asset Solution 2: Desilting No. 7 Dam

Description: Due to decreased water levels in the dam current, siltation and other material/vegetation build up is evident. Asset option A02 involved desilting/dredging of No. 7 dam to improve storage capacity and reliability of supply.

Will it work?: No. Water balance modelling was undertaken assuming that the full capacity of the dam was available. Given that is showed that the desired level of service could not be achieved based on full operating capacity, desilting will have no benefit on the water security profile. Council may pursue this for alternative reasons.

Asset Solution 3: Drinking water pipeline

Description: Option A03 involves the construction of a potable water pipeline connecting the Gracemere and Mount Morgan water supply networks. Since it is a potable supply, this option is considered to replace supply from No. 7 dam and therefore dam levels are expected to be sustained at higher levels. This option may therefore facilitate further environmental releases from No. 7 dam into the Dee River.

Will it work?: Yes. Since A03 (the Gracemere pipeline) is a potable supply, this option is a replacement supply, that is, providing volume necessary to supply the full supply the full demand for Mount Morgan under ongoing operation,

Asset Solution 4A: Raw water pipeline

Description: Option A04 involves the construction of a raw water pipeline fed from the lower Fitzroy River Water Supply Scheme. Option A04A involves connection to the Stanwell Water Supply Dam, with supplementary supplies provided to Mt Morgan.

Will it work?: Yes. Option AO4A (Stanwell Dam) and AO4B (SunWater) are considered to be supplementary supply options, where the existing supply source (No. 7 Dam) is retained within the supply scheme, and new sources provide a supplementary supply to the scheme during times when the dam is low and greater than level three restrictions are imposed.

Asset Solution 4B: Raw water pipeline

Description: Description: Option A04 involves the construction of a raw water pipeline fed from the lower Fitzroy River Water Supply Scheme. Option A04B involves connection directly to the SunWater pipeline intake on the Eden Bann Weir that supplies Stanwell power station, with supplementary supplies provided to Mt Morgan.

Will it work?: Yes. Option AO4A (Stanwell Dam) and AO4B (SunWater) are considered to be supplementary supply options, where the existing supply source (No. 7 Dam) is retained within the supply scheme, and new sources provide a supplementary supply to the scheme during times when the dam is low and greater than level three restrictions are imposed.

Asset Solution 4C: Raw water pipeline with hydropower

Description: As per A04A, however with a hydropower scheme incorporated and discharge direct to No. 7 dam. Stanwell have undertaken early investigation into a hydropower system incorporating No. 7 dam.

Will it work?: No. Discussions with Stanwell outlined their early investigations into hydropower, involving No. 7 dam. They noted substantial costs involved in the project and that it was presently unviable.

Asset Solution 5: Nine Mile Creek Dam

Description: Option A05 considers the construction of a dam on the Nine Mile Creek, approximately AMDT 2.5km. The dam would be downstream of the existing Fletcher Creek Weir and provide a supplementary water source to No. 7 Dam.

Will it work?: No. Earlier work by Holmes (2010) shows that the cost of building a dam at Nine Mile Creek was three to four times the cost of a pipeline option to Rockhampton. Regulatory approvals are likely to result in significantly longer delivery time frames comparative to other options.

Asset Solution 6: Fletcher Creek Weir Upgrade

Description: Option A06 involves repair and reinstatement of the Fletcher Creek Weir system.

Will it work?: No. Review of water balance modelling against Fletcher Creek inflows has shown there is no flow in Fletcher Creek coincident with low levels in No. 7 dam. Therefore, limited benefits are expected from this option.

Asset Solution 7: Desalination plant at Port Alma

Description: Option A07 considers the construction of a desalination plant at Port Alma, located 62km east of Rockhampton.

Will it work?: No. Brine management is a known issue with desalination which may lead to substantial cost increased to the project. Further, the distance of pipeline required to the Port Alma site is substantially longer than others considered, with further additional cost expected for desalination treatment processes.

Asset Solution 8: Effluent reuse

Description: This option considers whether recycled water from Mount Morgan or Gracemere could be utilised for town supply.

Will it work?: No. Insufficient volumes available, unlikely to be accepted by community, additional treatment required and due to treatment, civil infrastructure and ongoing management needs, likely to be cost prohibitive.

Asset Solution 9: Groundwater

Description: An option considering local groundwater supplies.

Will it work?: No. Insufficient volumes available.

Asset Solution 10: Offtake on F2G (Fitzroy to Gladstone)

Description: The Fitzroy to Gladstone pipeline “F2G” is an option to address water security concerns within the Gladstone region. The pipeline will span approximately 115km and will transfer bull water from the Fitzroy River and Gladstone. Since the pipeline takes off from the Fitzroy, an opportunity to connect to this main is considered for Mount Morgan.

Will it work?: No. With uncertainty around project timing for the F2G, there is potential that it would not be available in a timely manner to provide further relief to Mount Morgan. Further the operating regime for the future F2G is unknown, and there is a chance that it is not in operation when Mount Morgan requires it. There is also a cost risk for this option.

Asset Solution 11: Individual rainwater tanks

Description: This option reviews local hydrology and potential benefits of installing rainwater tanks at all households in Mount Morgan.

Will it work?: No. Water balance modelling of rainwater tanks showed that the local climate cannot sustain residential supply even with tanks in place.

Asset Solution 12: Mine water reuse

Description: Considers recycling of mine water from the mine pit at Mount Morgan mine.

Will it work?: No. The volume available from this resource is expected to be a fixed volume and would be depleted over time. There is also further uncertainty if this water would be available due to the proposed reprocessing of tailing by Heritage Minerals. This option was also previously ruled out through community consultation.

Originally published as Council votes on Mount Morgan water security preliminary evaluation