Reimagining Tarraleah

Tarraleah is an important part of our Battery of the Nation vision and activity kicked off in late 2022, with a start on upgrades to the existing scheme and a dive into the commercial feasibility of reimagining Tarraleah.

Project update April 2024

NEW!! Change to Butlers Gorge Road access

From Saturday 17 February to Sunday 26 May, Butlers Gorge Road will be closed 7 days a week between 7am and 5pm, to allow for road upgrade works. The road is open outside of these hours, providing access to the lookout and boat ramp.

From Monday 13 April, Butlers Gorge Road access will return to weekday closure from 7am – 5pm until at least August 2024. The road is open outside of these hours, providing access to the lookout and boat ramp.

The road access has been changed to ensure public safety.

The Lake King William campground will remain closed for the foreseeable future.

There is no change to access to Mossy Marsh Dam which remains open for anglers and recreational use.

Latest on the project

It has been a busy and productive time. We have advanced the upgrade works, progressed the approvals process and continued progressing our design and procurement processes. The latest project update for the Tarraleah redevelopment is now available, covering all of this and more! You'll find the update in the top right under the heading "Project Updates".

Environmental Effects Report

We're getting ready for the next stage of upgrade works at Lake King William. This includes constructing the new water intake and approach channel, tunnel excavation, blasting and associated materials screening and crushing.

An Environmental Effects Report (EER) has been prepared based on guidelines provided by the Environmental Protection Agency (EPA). Public comments have now closed and the EPA has made its determination to allow progressing water intake upgrade works at Lake King William.

Access to Mossy Marsh Dam re-opened

Access to Mossy Marsh Dam has now re-opened for anglers and recreational users. Thanks for your patience as we allowed the area to rehabilitate after the completion of dam upgrade works.


Project approvals

In March 2023, we lodged a referral to the Commonwealth government under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act). We’ve put together some information on the process and what our studies found.

We will keep you updated as we progress our approvals and let you know when there are further opportunities to comment.

Tarraleah Redevelopment - EPBC Referral

Scroll through this presentation to find out more about the proposed Tarraleah redevelopment and how we plan to gain commonwealth government approvals under the Environment Protection and B…


Impacts and opportunities

Thank you to everyone who has already shared their views on Tarraleah’s future. It is important for us to hear how the community feels about the proposed project and work on how we can address concerns, issues and opportunities. In our consultations to date, some of the impacts and opportunities raised are:

  • Traffic on the Lyell Highway
  • Workforce accommodation
  • Access to lakes for recreation
  • Storage levels and river flows
  • Benefits sharing
  • World Heritage values
  • Wildlife
  • Cultural heritage
  • Historic values

You can read more about the areas of interest and status in our project update.

Special Places?

We’re keen to hear from the broader community about the places around Tarraleah that you value, so that we can ensure the values you hold in those places are protected.

  • If there’s a particular place you want to tell us more about, head to our ‘pin mapto let us know what you value, where your concerns are and share your ideas!

For the latest on this project, bookmark this page or hit the subscribe button to get updates straight to your inbox.


Environmental approvals


Environmental approvals

We are now starting the environmental approvals process for a future redevelopment that includes federal, state and local government approvals processes. This starts with a referral under the Environment Protection and Biodiversity Conservation Act 1999  (EPBC Act) being lodged. The EPBC Act is a national statute of environment and heritage protection and biodiversity conservation. It focuses on protecting matters of national environmental significance. Find out more here.

The EPBC referral will determine if the project triggers a further formal assessment for potential impacts to what are termed 'Matters of National Environmental Significance' or MNES under the EPBC Act.

Through our studies, we identified that the construction and operation of a redeveloped scheme has the potential to impact on the following MNES:

  • suitable habitat for the threatened riparian plant species, native wintercress (Barbarea australis) at limited locations in the Derwent River between Derwent Pumps and Wayatinah Lagoon
  • Barbarea australis downstream of Liapootah and Wayatinah dams
  • the ‘alpine sphagnum bogs and associated fens’ ecological vegetation community at Mossy Marsh
  • habitat of the Tasmania wedge-tailed eagle, masked owl, Tasmanian devil, spotted tailed quoll and eastern quoll
  • Tasmanian Wilderness World Heritage Area (TWWHA) downstream of Derwent Pumps and upstream of Wayatinah Lagoon.

We are working to mitigate impacts on these matters and conditions may be applied to the project as part of its approvals. The EPBC assessment process includes environmental baseline and impact assessment studies that allow us to identify potential impacts and mitigation measures. We are also working to ensure any potential downstream impacts are mitigated, by consulting with irrigators and recreational users of other waterways below Tarraleah.

How to keep up to date with the process

The EPBC Referral period for public comment has now closed. The Department of Climate Change, Energy, Environment and Water (DCCEEW) will now continue its assessment process. You can track progress through the assessment process at the EPBC Act Public Portal (the reference is EPBC Number: 2023/09482).

We will keep you informed of the options available to avoid and / or mitigate impacts and also any conditions on the EPBC approval, as we move through the process. This site will be regularly updated so keep an eye out and subscribe to stay in touch.

Curious to know more about the assessment process? We’ve put together some information and also details of how you can get involved here.

Tarraleah Redevelopment - EPBC Referral

Scroll through this presentation to find out more about the proposed Tarraleah redevelopment and how we plan to gain commonwealth government approvals under the Environment Protection and B…


Upgrade works


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

Work started in August last year on the staged program of upgrades that includes:

  • Construction of a new intake at Lake King William

  • Dam safety improvements at Mossy Marsh Dam and creating a new emergency spillway location

  • Road and services access to the upgrade construction sites.

Public access near construction areas at Lake King William and Mossy Marsh Dam have changed during the construction period to ensure everyone’s safety. As many of the work sites are quite remote, we're expecting limited impacts.

The good news is the boat ramp at Lake King William isn't affected. The campsite will be impacted during the construction period. We have temporarily closed the campground. We expect it to be closed until the end of 2023 and apologise for any inconvenience.

To ensure public safety, Butlers Gorge Road (from the Lyell Highway turnoff) will be closed on weekdays between 7am and 5pm for 12 months until at least August 2024.

Mossy Marsh Dam

The works are to improve safety of the existing embankment and provide a controlled and safe spillway. Thee works don’t affect or change the way water is managed in Mossy Marsh. There will also be upgrade works to Butlers Gorge Road, including new culverts, to maintain access in flood conditions.

Our upgrade works to Mossy Marsh Dam have reached practical completion, however, public access remains closed to allow the area to rehabilitate. We expect the site to be re-opened for anglers and recreational users by December 2023. The map below details the works completed.



Lake King William

The work to construct a new intake on Lake King William suits a range of future scenarios for the Tarraleah scheme.

The existing conveyances (No 1 and No 2 canal) are ageing and will need to be replaced with a new single conveyance in the future, regardless of a potential future redevelopment. Upgrading the conveyance would require a new intake on Lake King William, which is one of the works packages being progressed. The work will also address limitations of the existing ageing assets.

The location for the proposed intake is in a bay ~1 km north east of Clark Dam. If a Final Investment Decision is not reached in future on a potential redevelopment, these works will support the conveyance upgrade to ensure the scheme can continue to operate safely and reliably into the future.


Lake King William – Switchyard Track access and campground closure

During construction activity, we have made changes to Switchyard Track access and also temporarily closed the campground. The map shows the changes to the track access which will be for an extended period to the end of 2024 when we expect that work on the new intake structure construction will be finished. The campground will be closed until further notice (likely the end of 2023). We apologise for any inconvenience. You can continue to access the public boat ramp.

Butlers Gorge Road closure

Our teams are continuing works at Lake King William for constructing a new water intake and Butlers Gorge Road (from the Lyell Highway turnoff) remains closed on weekdays between 7am and 5pm until at least August 2024.

The lookout and boat ramp are accessible outside of these hours and on public holidays and weekends. The Lake King William campground will remain closed for the foreseeable future.


Please be aware that we will need to do traffic management as we bring equipment to site.


The new intake

The concept below shows what the completed intake will look like.



A possible new future for the Tarraleah scheme

Sitting at the top of the Derwent hydropower scheme, Tarraleah is one of our oldest and most recognisable assets, with a network of canals and 6 enormous penstocks that transport water 290m down to Tarraleah Station in the Nive Valley. Tarraleah's labyrinth of tunnels, canals and pipes were an engineering triumph that have supplied Tasmanians with dependable energy for more than 80 years.

In today's electricity market (called the NEM), the demand for clean energy from wind and solar is rising and so is the need for a way to fill the gaps when the sun isn't shining or the wind isn't blowing. That's where hydropower comes in! We're looking at how we can adapt our assets - including Tarraleah - to make sure they're ready to meet these new needs.

with support from the Australian Renewable Energy Agency, we investigated how to reimagine the scheme, to make it better suited to deliver what the future electricity market will need. Our study showed the scheme could be redeveloped to increase capacity and flexibility - all valuable requirements in future.

For more information on these plans, read here.

The role of the community

We'll keep the community updated on what's happening with our commercial assessment and upgrade works and wherever possible, we'll avoid or minimise disruptions with on-ground works. Hit the subscribe button to receive updates straight to your inbox.

In the meantime, if you have a question about the works or a perspective you'd like to share, you can either contact us or post a question below.

Tarraleah is an important part of our Battery of the Nation vision and activity kicked off in late 2022, with a start on upgrades to the existing scheme and a dive into the commercial feasibility of reimagining Tarraleah.

Project update April 2024

NEW!! Change to Butlers Gorge Road access

From Saturday 17 February to Sunday 26 May, Butlers Gorge Road will be closed 7 days a week between 7am and 5pm, to allow for road upgrade works. The road is open outside of these hours, providing access to the lookout and boat ramp.

From Monday 13 April, Butlers Gorge Road access will return to weekday closure from 7am – 5pm until at least August 2024. The road is open outside of these hours, providing access to the lookout and boat ramp.

The road access has been changed to ensure public safety.

The Lake King William campground will remain closed for the foreseeable future.

There is no change to access to Mossy Marsh Dam which remains open for anglers and recreational use.

Latest on the project

It has been a busy and productive time. We have advanced the upgrade works, progressed the approvals process and continued progressing our design and procurement processes. The latest project update for the Tarraleah redevelopment is now available, covering all of this and more! You'll find the update in the top right under the heading "Project Updates".

Environmental Effects Report

We're getting ready for the next stage of upgrade works at Lake King William. This includes constructing the new water intake and approach channel, tunnel excavation, blasting and associated materials screening and crushing.

An Environmental Effects Report (EER) has been prepared based on guidelines provided by the Environmental Protection Agency (EPA). Public comments have now closed and the EPA has made its determination to allow progressing water intake upgrade works at Lake King William.

Access to Mossy Marsh Dam re-opened

Access to Mossy Marsh Dam has now re-opened for anglers and recreational users. Thanks for your patience as we allowed the area to rehabilitate after the completion of dam upgrade works.


Project approvals

In March 2023, we lodged a referral to the Commonwealth government under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act). We’ve put together some information on the process and what our studies found.

We will keep you updated as we progress our approvals and let you know when there are further opportunities to comment.

Tarraleah Redevelopment - EPBC Referral

Scroll through this presentation to find out more about the proposed Tarraleah redevelopment and how we plan to gain commonwealth government approvals under the Environment Protection and B…


Impacts and opportunities

Thank you to everyone who has already shared their views on Tarraleah’s future. It is important for us to hear how the community feels about the proposed project and work on how we can address concerns, issues and opportunities. In our consultations to date, some of the impacts and opportunities raised are:

  • Traffic on the Lyell Highway
  • Workforce accommodation
  • Access to lakes for recreation
  • Storage levels and river flows
  • Benefits sharing
  • World Heritage values
  • Wildlife
  • Cultural heritage
  • Historic values

You can read more about the areas of interest and status in our project update.

Special Places?

We’re keen to hear from the broader community about the places around Tarraleah that you value, so that we can ensure the values you hold in those places are protected.

  • If there’s a particular place you want to tell us more about, head to our ‘pin mapto let us know what you value, where your concerns are and share your ideas!

For the latest on this project, bookmark this page or hit the subscribe button to get updates straight to your inbox.


Environmental approvals


Environmental approvals

We are now starting the environmental approvals process for a future redevelopment that includes federal, state and local government approvals processes. This starts with a referral under the Environment Protection and Biodiversity Conservation Act 1999  (EPBC Act) being lodged. The EPBC Act is a national statute of environment and heritage protection and biodiversity conservation. It focuses on protecting matters of national environmental significance. Find out more here.

The EPBC referral will determine if the project triggers a further formal assessment for potential impacts to what are termed 'Matters of National Environmental Significance' or MNES under the EPBC Act.

Through our studies, we identified that the construction and operation of a redeveloped scheme has the potential to impact on the following MNES:

  • suitable habitat for the threatened riparian plant species, native wintercress (Barbarea australis) at limited locations in the Derwent River between Derwent Pumps and Wayatinah Lagoon
  • Barbarea australis downstream of Liapootah and Wayatinah dams
  • the ‘alpine sphagnum bogs and associated fens’ ecological vegetation community at Mossy Marsh
  • habitat of the Tasmania wedge-tailed eagle, masked owl, Tasmanian devil, spotted tailed quoll and eastern quoll
  • Tasmanian Wilderness World Heritage Area (TWWHA) downstream of Derwent Pumps and upstream of Wayatinah Lagoon.

We are working to mitigate impacts on these matters and conditions may be applied to the project as part of its approvals. The EPBC assessment process includes environmental baseline and impact assessment studies that allow us to identify potential impacts and mitigation measures. We are also working to ensure any potential downstream impacts are mitigated, by consulting with irrigators and recreational users of other waterways below Tarraleah.

How to keep up to date with the process

The EPBC Referral period for public comment has now closed. The Department of Climate Change, Energy, Environment and Water (DCCEEW) will now continue its assessment process. You can track progress through the assessment process at the EPBC Act Public Portal (the reference is EPBC Number: 2023/09482).

We will keep you informed of the options available to avoid and / or mitigate impacts and also any conditions on the EPBC approval, as we move through the process. This site will be regularly updated so keep an eye out and subscribe to stay in touch.

Curious to know more about the assessment process? We’ve put together some information and also details of how you can get involved here.

Tarraleah Redevelopment - EPBC Referral

Scroll through this presentation to find out more about the proposed Tarraleah redevelopment and how we plan to gain commonwealth government approvals under the Environment Protection and B…


Upgrade works


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

Work started in August last year on the staged program of upgrades that includes:

  • Construction of a new intake at Lake King William

  • Dam safety improvements at Mossy Marsh Dam and creating a new emergency spillway location

  • Road and services access to the upgrade construction sites.

Public access near construction areas at Lake King William and Mossy Marsh Dam have changed during the construction period to ensure everyone’s safety. As many of the work sites are quite remote, we're expecting limited impacts.

The good news is the boat ramp at Lake King William isn't affected. The campsite will be impacted during the construction period. We have temporarily closed the campground. We expect it to be closed until the end of 2023 and apologise for any inconvenience.

To ensure public safety, Butlers Gorge Road (from the Lyell Highway turnoff) will be closed on weekdays between 7am and 5pm for 12 months until at least August 2024.

Mossy Marsh Dam

The works are to improve safety of the existing embankment and provide a controlled and safe spillway. Thee works don’t affect or change the way water is managed in Mossy Marsh. There will also be upgrade works to Butlers Gorge Road, including new culverts, to maintain access in flood conditions.

Our upgrade works to Mossy Marsh Dam have reached practical completion, however, public access remains closed to allow the area to rehabilitate. We expect the site to be re-opened for anglers and recreational users by December 2023. The map below details the works completed.



Lake King William

The work to construct a new intake on Lake King William suits a range of future scenarios for the Tarraleah scheme.

The existing conveyances (No 1 and No 2 canal) are ageing and will need to be replaced with a new single conveyance in the future, regardless of a potential future redevelopment. Upgrading the conveyance would require a new intake on Lake King William, which is one of the works packages being progressed. The work will also address limitations of the existing ageing assets.

The location for the proposed intake is in a bay ~1 km north east of Clark Dam. If a Final Investment Decision is not reached in future on a potential redevelopment, these works will support the conveyance upgrade to ensure the scheme can continue to operate safely and reliably into the future.


Lake King William – Switchyard Track access and campground closure

During construction activity, we have made changes to Switchyard Track access and also temporarily closed the campground. The map shows the changes to the track access which will be for an extended period to the end of 2024 when we expect that work on the new intake structure construction will be finished. The campground will be closed until further notice (likely the end of 2023). We apologise for any inconvenience. You can continue to access the public boat ramp.

Butlers Gorge Road closure

Our teams are continuing works at Lake King William for constructing a new water intake and Butlers Gorge Road (from the Lyell Highway turnoff) remains closed on weekdays between 7am and 5pm until at least August 2024.

The lookout and boat ramp are accessible outside of these hours and on public holidays and weekends. The Lake King William campground will remain closed for the foreseeable future.


Please be aware that we will need to do traffic management as we bring equipment to site.


The new intake

The concept below shows what the completed intake will look like.



A possible new future for the Tarraleah scheme

Sitting at the top of the Derwent hydropower scheme, Tarraleah is one of our oldest and most recognisable assets, with a network of canals and 6 enormous penstocks that transport water 290m down to Tarraleah Station in the Nive Valley. Tarraleah's labyrinth of tunnels, canals and pipes were an engineering triumph that have supplied Tasmanians with dependable energy for more than 80 years.

In today's electricity market (called the NEM), the demand for clean energy from wind and solar is rising and so is the need for a way to fill the gaps when the sun isn't shining or the wind isn't blowing. That's where hydropower comes in! We're looking at how we can adapt our assets - including Tarraleah - to make sure they're ready to meet these new needs.

with support from the Australian Renewable Energy Agency, we investigated how to reimagine the scheme, to make it better suited to deliver what the future electricity market will need. Our study showed the scheme could be redeveloped to increase capacity and flexibility - all valuable requirements in future.

For more information on these plans, read here.

The role of the community

We'll keep the community updated on what's happening with our commercial assessment and upgrade works and wherever possible, we'll avoid or minimise disruptions with on-ground works. Hit the subscribe button to receive updates straight to your inbox.

In the meantime, if you have a question about the works or a perspective you'd like to share, you can either contact us or post a question below.

  • Latest project update

    supporting image

    Keep up-to-date with the Tarraleah redevelopment project by checking out our latest project update. We provide information on the upgrade works underway, the findings of our community survey and what's happening with environmental approvals. You can read more here. As always, please get in touch if you have questions or would like to chat with a member of our project team.

  • Opportunity to comment

    supporting image

    We're getting ready for the next stage of upgrade works at Lake King William. This includes constructing the new water intake and approach channel, tunnel excavation, blasting and associated materials screening and crushing.

    An Environmental Effects Report (EER) has been prepared based on guidelines provided by the Environmental Protection Agency (EPA). Public comment is now invited on the report which you can access here. Comments are invited up to 25 November, 2023.

  • Upgrade works progress

    supporting image
    Upgrade works are progressing on the Tarraleah hydropower scheme. Hazell Bros Group have been busy on the excavation of the downstream tunnel entrance (technically called a portal) of the Lake King William tunnel. Construction of this 1km tunnel is set to start in early 2024. It will link the new intake at Lake King William to a future new conveyance that will feed water into Tarraleah Power Station.

    If you have questions about the upgrade works or the proposed new future for Tarraleah, please get in touch!

  • Butlers Gorge Road closure

    Butlers Gorge Road closed weekdays from 26 June

    Our teams are continuing works for construction of a new water intake at Lake King William. A new phase of activity for the connecting tunnel has kicked off and there will be increased heavy vehicle activity on the road. To ensure public safety, Butlers Gorge Road (from the Lyell Highway turnoff) will be closed on weekdays between 7am and 5pm for 12 months until August 2024.

    The lookout and boat ramp are accessible outside of these closure times and also on weekends. The Lake King William campground will remain closed for the foreseeable future.

  • Have your say on Tarraleah’s future

    supporting image

    Hydro Tasmania is progressing its assessment of a new future for the Tarraleah hydropower scheme. Hydro Tasmania has now started the Federal Government environmental approvals process relating to matters of national environmental protection and biodiversity conservation.

    A range of environmental studies have been completed to look at potential impacts from the proposed redevelopment and its future operation. These studies form the basis of the assessment and what further assessment steps are needed.

    The EPBC referral has been reviewed by the Department of Climate Change, Energy, Environment and Water (DCCEEW) for review and is now public. You can comment on the proposal and track progress through the assessment process through the EPBC Act Public Portal. It is open until Wednesday 19 April.

    Please reach out to the team if you have any questions!

  • Works kicked off at Lake King William

    Work has commenced on-site at Lake King William where the new intake will be constructed. The Switchyard Track beyond the boat ramp will be closed until further notice but you can still access the boat ramp.

    There will be increased traffic and truck movements in the area and along Butlers Gorge Road so please heed all warning and safety signage, and note that there may be traffic management may be in place at times.

    Please reach out if you have any questions about the Tarraleah project.