An independent review of options to reduce salinity in the Upper Collie Basin was an election commitment.
The water resources of the Upper Collie area support industry, mining, public water supplies, irrigators and the environment.
They currently provide water for energy producers supplying around 50 per cent of the South West of Western Australia’s power.
The resources are important for the community of the South West and the state.
Since the 1960s, the Collie River has become saline as a consequence of land clearing in the catchment. As a result, Wellington Reservoir has become unusable as a public water supply and marginal for irrigation supplies.
The increase in salinity has imposed significant socio-economic costs in the forms of land degradation and reduced agricultural output, environmental damage, reduced amenity, and the need to construct the Harris River Dam to provide potable water supplies.
In response to the increasing salinity, successive state governments since the mid 1970s have implemented mitigation options. These have included clearing controls and re-vegetation. In recent years, engineering options have been investigated and trialled.
The State Liberal Plan for Environmental Sustainability and Water Management discussed the issue of maximising the potential of Wellington Dam, and that ‘to leave the greater bulk of the Wellington Dam’s water unused or wasted is not in the best interests of the State’. In light of this, the government committed to two actions:
- To commission an independent science-based review of options to reduce salinity in Wellington Reservoir; and
- To implement a pilot expansion project to divert and treat 2.5 GL/year of saline river flows from the Collie East River.
Following the green light for the pilot expansion in June 2009 Water Minister Dr Graham Jacobs commissioned an independent assessment of different plans for improving the quality of the reservoir’s water.
The review was commissioned to make sure the most feasible and cost-effective solution was chosen.
The review looked at a total of 18 different proposals before narrowing them down to a shortlist of four and a final conclusion as to the most effective option.
Read the Minister’s media statement following the completion of the review.
A copy of a summary of the review can be downloaded here.
Frequently asked questions (FAQs) on the Independent review of options to reduce salinity in Wellington Reservoir
1. Why did the government need to do a review when the Department of Water already had a plan?
When the government came into power in 2008, the Water Minister announced his intention to ensure that efforts to improve the water quality in Wellington Reservoir would be advanced.
Following that call, the Minister received a number of plans and proposals to improve the water quality of the reservoir. These were in addition to the existing plan by the Department of Water, a trial of which was already approved and funded by the state and federal governments.
To ensure the best and most cost effective plan was chosen, the government decided such a decision required a science-based review that assessed all of the options on their merits.
2. Who did the review and was it independent?
Yes the review was independent. It was conducted by KPMG jointly with Worley Parsons.
3. What was reviewed?
The terms of the review were to:
- assess ALL available options to recover salinity in Wellington Dam and the Collie River
- assess the requirements of water quality in Wellington Reservoir to ensure sustainability and viability of the Collie Irrigation District
- assess the potential to deliver potable water from the Collie River Basin in the Integrated Water Supply Scheme
- assess the potential for developing an industrial water supply in the Collie River Basin
- provide a cost-benefit analysis of the options and opportunities, and
- make recommendations in regard to salinity recovery in the Collie River Basin.
4. How many options were reviewed?
The review attracted 18 public submissions. The consultants reviewed these and shortlisted four options.
5. How were the projects ranked and assessed?
The four shortlisted options were assessed for their technical feasibility, cost and physical outputs and a risk benefit analysis undertaken.
6. What were the four shortlisted options?
- The first option review was by company Agritech to deliver drinking quality water from Wellington Reservoir via a gravity fed desalination plant and associated infrastructure, accompanied by a saline diversion channel network to capture saline water from the Upper Collie Catchment with some diversion to desalination
- The second option reviewed was the Department of Water Collie salinity recovery plan staged engineering solution, now known as the pilot expansion project; diversion of saline water followed by treatment to remove salt loads; disposal of concentrated saline water to the ocean via Verve ocean outfall pipeline.
- The third option reviewed was submitted by Marsden Jacobs, and proposed the Department of Water option, but increasing the size of the engineering scheme to provide a source of water, accompanied by a water utility.
- The fourth option reviewed was submitted by the WA Forests Products Commission, and proposed supplementing the Department of Water option with expanded commercial plantations in the Upper Collie Catchment.
7. What option was recommended and why?
The Review has concluded that:
- The Department of Water’s option in conjunction with elements of the WA Forests Products Commission option is more likely than the other options to provide a cost effective way of improving water quality in Wellington Reservoir.
- The Department of Water’s staged engineering approach (and tree plantations) was the most cost effective way of achieving salinity reduction in Wellington Reservoir.
8. Can you explain why the other options were not recommended?
Overall, the review concluded that the other options examined represented less cost effective ways of achieving salinity reduction in Wellington Reservoir.
Specifically, in the reviewer’s opinion:
- The Agritech option was the least likely option to deliver fresh water to Wellington Reservoir in a way that would justify the costs involved with a particular note that the capital costs associated with the project were high and uncertain.
- The costs of the WA Forests Products Commission option appeared to be lower than elements of the Department of Water’s option or Marsden Jacobs’ option, but they were also less certain and required significant areas of private land with lower economic benefit compared to existing land uses.
- The WA Forests Products Commission’s and Marsden Jacobs’ options depended on the direction of the Department of Water’s option.
9. Did anything else come out of the review that was useful?
Yes. The review has greatly assisted the government in understanding better what the priorities for the region are, and what the obstacles are to achieving those priorities.
Some key directions which have come out of the review are:
- The need to optimise local water resources for regional development, including maximising the returns from the higher quality water created from treating the diverted water.
- The need to understand more clearly the demand for industrial water in the region and ways of managing the demand and supply balance to be feasible in the long term.
- The need to clearly define water resources management objectives for the Upper Collie area (including the appropriateness of the long-term 500 mg/L target for Wellington Reservoir). This is central to a cost-benefit justification of any investment by the government or the private sector.
10. Was this review a waste of time and money?
The government believes the review was not a waste of time and money because it has allowed for a full canvassing of the best options for water recovery and also allowed the government to prioritise its efforts in the area with all information to hand.
11. Now the review is finished, will anything actually be done?
It is important to note that something is already being done. The pilot expansion project to divert and treat 2.5GL a year of salty water flows from the east Collie River has been approved.
12. But isn’t this still pending a business case?
No, this is not right. The business case refers to extra funds to expand the pilot project to increase the diversion from 2.5GL to 4.5GL a year.
13. How long will it take to assess demand? Shouldn’t this already have been done?
Considerable work has already been conducted to make sure there is a demonstrated need for this improved water. But like any business proposal, we now need to move forward and establish how this will be realised in terms of paying customers and guaranteed contracts.
14. Why did the review take so long?
Successive governments have invested significant amounts of money addressing salinity issues in Collie with varying results. I need to be satisfied that future investments are the most cost effective and outcomes focussed.
15. Why has some of the information presented in the review not been made public? Why is the government only releasing a summary?
The process invited proponents to submit plans for feasibility assessment. Some of these plans involved intellectual property, information on proprietary technology and other aspects that were submitted commercial-in-confidence. This information legally cannot be released.