Parliamentary Committees

PUBLIC WORKS COMMITTEE: CLAYTON WATER SUPPLY

Ms CICCARELLO (Norwood) (11:01): I move:

That the 270th report of the committee, entitled Clayton Water Supply, be noted.

The township of Clayton relies on water extracted from Lake Alexandrina. Water is supplied to customers from the council operated scheme, three privately operated schemes and numerous individual owner operated systems. The council operated scheme supplies most of Clayton's residents. It uses an aquifer storage and recovery system to improve water appearance and protect against algal outbreaks. But that system is failing, with the extracted water quality having significant salinity gains and sand carryover, resulting in water of marginal quality.

The drought conditions being experienced and the impact on the River Murray system with ongoing low inflows will result in falling water levels within Lake Alexandrina. These have the potential to exceed the lower limit of the extraction infrastructure and are forecast to significantly increase water salinity to levels exceeding Australian Drinking Water Guidelines. The falling levels are forecast to continue as system inflows to the Lower Murray are well below the lake evaporation rate. This eliminates the ability to control the water pool level. It is proposed that filtered water from the Summit Storage Water Treatment Plant be supplied via a new 12.5 kilometre pipeline and ancillary works with an estimated cost of $5 million. The works will provide a new booster pump station at the Bremer tank to boost pressure during peak demand period to Milang and Clayton. The tank inlet control valve will be altered to ensure control of system pressures upstream of the Bremer tank during periods of high demand.

The new pipeline will be connected to existing reticulation infrastructure within each township, and three pressure reducing valve assemblies will be provided to control customer supply pressures. This project does not address some other issues of concern to the Clayton community such as low water pressure, and hydrants and stop valves considered unsatisfactory. It is limited to ensuring the water supply. The committee is told that other matters will be negotiated and dealt with within the next 18 months.

A detailed consultation with the community will include outstanding matters such as issues associated with the private water schemes and the future of the existing water tower after it is decommissioned. The committee was pleased to learn that this project will result in a much lower volume of water extraction from the River Murray than the present scheme, and this will still be the case if anticipated growth in services and consumption is achieved.

The objective of this project is to ensure the security of water supply to the township of Clayton, while also complying with the Australian Drinking Water Guidelines. The key driver is the increase in salinity of Lake Alexandrina in conjunction with falling lake water levels and declining water quality. The project will improve water quality by delivering filtered water and will provide infrastructure to permit future development and growth of the community whilst ensuring security and continuity of the supply. The new pipeline will also mitigate against the public safety and water supply contamination risks associated with algal blooms, associated toxin and cryptosporidium.

SA Water examined several options for the project using multicriteria analyses, including whole-of-life costs and a range of technical, social and environmental factors. The results of an economic analysis indicate a net present value cost for the project of around $4.4 million and a benefit cost ratio of 0.05. The preferred option has the lowest capital and operating cost, and hence best net present value and benefit cost ratio. The analysis makes allowance for increased water sales, which may result once customers receive filtered water. Generally a growth allowance of 1 per cent per year has been assumed. Construction is anticipated to have reached practical completion in December 2007. To achieve this time frame, SA Water is working with the construction industry to progress the detailed design and to achieve significant improvements in the construction program.

All materials required are considered to be readily available off-the-shelf items. There are some risks, including the declining pool level in the River Murray, or salinity level increases within Lake Alexandrina. SA Water is investigating the lake extraction infrastructure to ensure it remains operational until the new pipeline is operational. SA Water's formal assessment process has been used to identify other significant risks and develop mitigation strategies. Based upon the evidence presented and pursuant to section 12C of the Parliamentary Committees Act 1991, the Public Works Committee reports to parliament that it recommends the proposed public work.

Mr PEDERICK (Hammond) (11:06): I congratulate the Public Works Committee on looking into the water supply at Clayton. It has been an issue—

An honourable member interjecting:

Mr PEDERICK: Absolutely; and extremely good members on this side of the house and one or two on the other side of the house are quite good as well. The community of Clayton had at least six different water schemes. It has been in strife with ageing infrastructure. It is good to see the government come on side to hook them up to a scheme to the River Murray. There are certainly issues with salinity, and this has not been helped by the lack of effective maintenance on the barrages on the Lower Lakes. Certainly pool levels are dropping, but there are predictions now, with all the ingress from the sea, that the lake levels will not recede as far as first thought, which means that there will be a lot of unusable saltwater in the lakes. I believe that, in the longer term, the government will be looking at emergency desalination options for any off-takes off the River Murray.

I hope it has that on notice. My farm relies on the Keith pipeline and any just-in-time pipelines such as towards Wistow, etc., and even towns such as Murray Bridge, will need emergency desalination because of the lack of infrastructure work in the past. I believe that the water will get saltier because of the lack of maintenance. However, I commend the installation of this new facility to get better water infrastructure and a better water supply for the citizens of Clayton. It is a very nice spot in my electorate. It is a lovely place to visit and to talk to my constituents.

The Hon. R.B. Such: Do they vote for you?

Mr PEDERICK: Absolutely.

The Hon. R.B. Such: All three of them!

Mr PEDERICK: No, there are a few more than three. I commend SA Water for making a commitment to the committee that it would put a fire hydrant near the CFS shed for fire control work at Clayton, and I applaud it for that. I look forward to further improvements in the future to enhance the beautiful and serene spot of Clayton.

Mr PENGILLY (Finniss) (11:09): I also support the report on the Clayton water supply. I am very pleased that the inquiry has taken place. Clayton was part of my electorate for many years during the term of my predecessor the Hon. Dean Brown and, before him, the Hon. Ted Chapman. Clayton is near and dear to those of us with electorates surrounding that area. The 12.5 kilometre

pipeline will be a great asset, and I would like to commend the Alexandrina council for making a water supply available for many years to the township of Clayton. The Alexandrina council has gone out of its way to support that community and, indeed, support those communities up along the western side of the lakes and the river. I applaud the council for what it has done.

As my colleague the member for Hammond has indicated, the barrages are leaking, which is a major concern. It has been an absolute total failure by this government not to remedy the leaking of those barrages. The government has been notified of it on several occasions. The Minister for Water Security has been told about it; she scoffed at it and very little has been done about it. It seems to me that people around the traps who do have practical knowledge of these matters are being ignored by the government, the Premier and the minister on these issues. I do hope that, as the member for Hammond said, this situation does not deteriorate much further.

Picking up on the honourable member's point, I think that, in the future, desalination will be absolutely essential down around those lake communities. It is the only way they will get around it. We continue to pound it, but the poor old Murray just cannot supply all the water that is required of it. Equally on that note, the government has failed dismally to provide a desalination plant to pick up on the requirements of Adelaide. As much as we need desalination for the future down around those lake communities we urgently need it in Adelaide. I think it is about time that some action was taken. We need less chat and more action on the ground. The Clayton community is most pleased to have this supply, and I look forward to the day when it is switched on and operational. I commend the report.

Motion carried.