Public Works Committee: Taplan Elevated Water Tank Project

Mr BROWN (Florey) (11:20): I move:

That the 72^nd report of the committee, entitled Taplan Elevated Water Tank Project, be noted.

The South Australian Water Corporation, or SA Water, proposed to replace an existing aged elevated water tank at Taplan with a larger 700-kilolitre tank to ensure a reliable water supply to existing customers and support growth in the Taplan township and surrounding region. The township of Taplan is approximately 280 kilometres east of Adelaide near the border with Victoria in the Murray Mallee region. It is currently supported by a 40-year-old elevated water tank, with a capacity of 136 kilolitres. As it is a critical asset for the water supply network to the Taplan township, which services around 700 regional customers, the tank has surpassed its design life and needs replacement.

The ageing tank has experienced excessive leakage from its floor joints, causing significant ground disturbance, posing an increased water security and safety risk. In the past the system has experienced several periods of high demand during the summer months, which has resulted in low water pressure to customers and heightened the risk of the tank being completely drained, with the potential for customers unable to be supplied with mains water.

This further reinforces that reliance on this aged infrastructure increases the likelihood of service disruptions, which can severely impact customers. Projected growth in the Taplan area and corresponding demand on the system is constrained by the current tank and requires the capacity to be increased.

The key aims of the project are to sustain services and enable growth in the Taplan area to ensure the long-term viability and delivery of reliable baseline services to existing customers. It also seeks to support an expanded network to meet increasing demand in the area. These aims will be achieved by replacing the existing 136-kilolitre elevated tank and support structure with a new 700-kilolitre water storage facility, comprising a 140-kilolitre elevated water tank structure and a 560-kilolitre ground tank, alongside associated equipment.

This will involve the demolition of the existing tank and support structure, followed by construction of the new elevated tank, with connections to the new ground tank and associated infrastructure upgrades to support both tanks. SA Water states that this is a resilient solution that fortifies water security within the network. The elevated water tank provides water supply to customers at a constant pressure due to the gravity feed solution, while the ground tank provides the additional water storage required by the high-demand summer periods while providing additional capacity for the expected future growth in the Taplan area.

The current site of the water tank is on land owned by SA Water. For the construction of the new tank, SA Water will investigate and acquire adjacent land in accordance with the Land Acquisition Act. Where possible, impacts will be minimised and the exact size of the land to be acquired will be determined as part of the project's detailed design phase.

The cost of the project is $11.35 million. Construction works have commenced, with completion anticipated by the first quarter of 2026. The project will be managed by a project manager from SA Water's Capital Planning and Delivery Group. SA Water also has a business risk management policy, used to identify risks and determine the related impacts and their likelihood as well as develop mitigation strategies to remedy problems. This policy and framework will be applied over the course of the project.

Key risk management strategies for the project include:

a recirculation system designed to manage water quality by recirculating water between the ground and elevated tanks;

a detailed construction execution plan to mitigate the risks posed by undertaking construction tasks at an elevated height, including a combination of landing and aerial work platforms, the inclusion of guardrails, appropriate personal protective equipment and administrative controls put in place to support construction activities;

the set-up of a temporary bypass to take the existing tank offline and provide continuous water supply to the region during construction, lessening the risk of the current tank failing before the completion of the new tank; and

the increase of the height of the elevated structure by 1.5 metres to mitigate against the inability to adjust pressure in the network.

SA Water has a commitment to operating sustainably to support viability now and into the future. An environmental control plan has been prepared to ensure the project is delivered in compliance with relevant legislative frameworks. In compliance with the Native Vegetation Act, approval has been granted for the clearance of native vegetation in a predefined area, ensuring that surrounding roadside vegetation is protected from construction and operational impacts. Regarding water, sediment and drainage management, all reasonable and practical measures will be implemented to prevent pollution and environmental harm.

Construction and laydown zones will be appropriately established to minimise the potential for surface run-off to enter the site, alongside controls used to minimise potential for run-off to leave the site. Stockpile and laydown areas will be designated away from drainage lines or low-lying areas, while disturbed or unsealed areas will be compacted, backfilled and resurfaced as soon as possible. Discharges associated with the commissioning of the tank will be undertaken in line with SA Water's best practice operating procedure for water-affecting activities.

The project has been assessed by an Aboriginal heritage adviser and has been given a medium risk of impacting or encountering heritage, as SA Water recognises any ground-disturbing activity presents a risk of encountering Aboriginal objects or remains. In the unlikely event of heritage being uncovered, the project will follow SA Water's standard operating procedures for the discovery of Aboriginal heritage, with work ceasing immediately and an Aboriginal heritage and engagement adviser being contacted.

Native title implications have been reviewed and been determined to be extinguished, provided the infrastructure and construction work remain within the gazetted road reserves and within previously disturbed corridors through SA Water-owned land parcels, including the land to be acquired. If the project works were to impact land that may be subject to native title, native title holders and registered native title claimants will be notified. Communication with relevant stakeholders is ongoing and will continue throughout the project. Consultation will also occur with the local council of Loxton Waikerie and the landscape board.

The committee examined written and oral evidence in relation to the Taplan Elevated Water Tank project. Witnesses who appeared before the committee were Peter Seltsikas, Senior Manager Capital Delivery, SA Water and Maria Nordberg, Senior Project Manager, SA Water. I thank the witnesses for their time.

Based upon the evidence considered 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.

Motion carried.