Tarraleah FAQ

• What did the feasibility study look at?

  • We assessed two scenarios to identify the preferred future strategy for the scheme.
    1. Redevelopment
       • This is about transforming the scheme’s capability to better suit the anticipated needs of the future energy market (by making it more flexible and responsive to changes in demand).
       • This would involve a lot of new infrastructure - a new power station and potentially new water conveyances (that transport water). This will boost the scheme's capacity and ability to deliver more energy annually – essentially getting more value from the same water resource.

  2. Refurbishment

  • This is about maintaining existing capability. The scheme assets would be refurbished and in some cases replaced, to ensure they continue to operate safely and reliably well into the future.
  • In this scenario, the scheme will continue to operate as ‘baseload’ with similar capacity and annual energy production. Baseload refers to a generation resource that generally runs continuously throughout the year and operates at stable output levels.

  The technical part of our study is complete. In March 2021, ARENA and Hydro Tasmania released a knowledge sharing report that presents a framework for making hydropower asset management decisions in a future energy market context, using Tarraleah as a case study. You can access the report here - Repurposing hydropower assets for future market. 
  

  
  

• Why redevelop Tarraleah?

  • The future energy market will need supply options that can be quickly switched on when needed. A future redevelopment of Tarraleah would bring:
    • Greater scheme capacity - it’s like having a bigger engine in your car!
    • Generating more renewable energy annually.
    • Allowing faster and more flexible station operation that is better suited to supporting the growth of wind and solar power.

  
  

• What is proposed for the existing Tarraleah Power Station?

  The Tarraleah station is iconic and has a rich history. It’s important that we understand those heritage values and make a plan for managing and preserving the historic station, and other parts of the scheme that may have value, should they no longer be needed for power generation.

  

  A redevelopment of the scheme would mean the construction of a new power station in a nearby location.

  • The existing station would continue to operate while the construction work is underway so that we don’t impact on our ability to generate energy.
  • When the new station is completed, the existing station would be taken out of service and managed in line with what’s recommended in our heritage study.

  Refurbishment  of the scheme means we'd maintain the existing station and do the work needed so it can continue to operate safely and reliably. The six turbines and generators are near the end of their life and will need to be replaced with brand new machines, along with replacement or refurbishment of other parts of the station.

  
  

• What is proposed for the water conveyances?

  • The Tarraleah scheme has two complex water transfer systems from Lake King William to the Tarraleah Power Station – totalling about 30 kilometres of open canals, flumes (a type of water channel), tunnels, pipelines and ponds.
  • Most of the components are now 60-80 years old and nearing the end of their asset life.
  • Under both scenarios, there could be a new water conveyance replacing the existing infrastructure, allowing water to be transferred more efficiently to the new power station.

  We have identified our preferred development option – a full redevelopment with a pressurised water conveyance. We conducted a rigorous analysis of five options, carefully considering the social, environmental, commercial, and economic risks and benefits of each option. 

  Our preferred option delivers the greatest capacity, storage, flexibility and reliability for every dollar invested, while addressing environmental risk. 
  

  
  

   

   

  
  

• What is proposed for the current water storages?

  • The scheme has a large headwater storage at Lake King William, and several smaller storages: Mossy Marsh Pond, and what we call No. 1 Pond and No. 2 Pond. We’re looking at what role those smaller storages could play in the future.
    

  
  

  
  

• What are the impacts of changing the scheme?

  • The good news is that when we did a pre-feasibility study in early 2018, we looked at possible environmental and social impacts and didn’t find any potential high risks or impacts. This has been confirmed through our ongoing assessments which show that risks and impacts remain low. 
  • As part of our current studies, we've now:
    • Identified environmental and social values and what will be needed to maintain or enhance those values
    • Established 'baseline' conditions for environmental and social aspects of the scheme and its surrounds
      • surveyed what’s growing and living in the waterways – hydrological modelling and aquatic ecology surveys
      • surveyed what’s growing and living in and around the scheme – terrestrial ecology surveys
      • surveyed the area and scheme history including Aboriginal and built heritage assessments and field surveys.

  • Determined the nature and extent of any likely impacts from what is proposed so that we can identify mitigation measures.

  
  

• Next steps

  In April 2022, the Federal Government announced a funding commitment of up to $65M to support progressing works on Tarraleah. This includes assessing the commercial viability of redevelopment and completing a program of upgrade works that position the scheme well for the future, regardless of the outcome of the commercial decision.

   

  We're well advanced on a program of upgrades associated with a future new single water conveyance, staged over the next couple of years. There’s more activity and vehicle movements around Lake King William and Butlers Gorge Road. Some public access near construction areas has also changed during the construction period to ensure everyone's safety.

   

  There is a new Tarraleah project site where you can find more, ask questions and subscribe to updates as the project progresses.

  We're required to seek approvals at a state and local level:
  

  • various state level environmental approvals
  • state parliamentary approval to construct a new hydropower asset (the power station)
  • local council approval for a scheme development application (DA) as well as building approval for various parts of the scheme.

   

  As part of our commercial assessment, we will be consulting with the community about a range of things including:

  • studies we are doing to understand potential impacts and how they can be mitigated (traffic and noise, visual impact, environmental impacts). Many of these studies are already underway.
  • the environmental approvals process at a Federal, State and Local level.

   

  As the studies progress, seeking the views of the community will be important. We want to better understand from the community any potential concerns or issues about what is proposed and how potential impacts can be mitigated.
  

   

  Stay in touch on our project page for upcoming opportunities to chat with us.

  
  

• Can I provide feedback?

  We welcome feedback from the Tasmanian community.

  There is a new Tarraleah project site where you can find more, ask questions and subscribe to updates as the project progresses.