Edgar Dam Upgrade

Hi Mark,

Thanks for your message - we think it's a wonderful spot to relax too! 

The campground will definitely reopen once works have finished. We're hoping we might even add some improvements. We'd love to hear ideas about what we could do and as a regular visitor, I am sure you've got some. You can share them directly to jane.alpine@hydro.com.au.

Cheers

Jane

Hi Anne,

Thanks for visiting the page and posting a question. 

While we can’t provide specific comment on a particular operation, shock waves from quarry scale blasting operations are typically considered to be short, sharp and low in intensity, as compared with an earthquake scale ground movement. This means they impart significantly less energy to ground mass.

For a more comprehensive answer, you’d need to contact the relevant contractor(s) directly. Modern blasting projects will have a blast management plan that should include consideration of any infrastructure (residential or public) impacts.

Many thanks

Jane

Morning Phil,

Thanks for popping by and posting a question. The water levels of Lake Pedder or Edgar Pond won't be affected by the upgrade works. 

Cheers

Jane

Dear Richard,

Thank you for visiting the project page and posting your questions.

One of the main purposes of this page is to share key updates, as that information becomes available. There has been little to report until last week, when a decision on the Federal Environment Protection and Biodiversity Conservation Act 1999 referral was announced. I shared an update on this outcome, along with news on the quarry investigation and upcoming tender process. You suggested that the public comment period for this referral was extended but this is not the case - the standard 10 business day period was applied.     

While Lake Edgar Fault does influence dam risk, it is important to highlight that this risk is associated with a major earthquake, not minor or moderate earth tremors, and such a scenario is extremely unlikely to occur. Remote 24/7 monitoring, weekly in-person inspections and routine safety review processes are all important components of the monitoring program that applies to all Hydro Tasmania’s large dams (including Edgar and Scotts Peak dams) and help mitigate a range of risks. Regular dam maintenance and upgrades also play a critical role in reducing risk – in the case of Edgar Dam, the upcoming works will deliver a significant risk reduction. Relevant safety information is shared with the Department of Natural Resources and Envirornment Tasmania (the regulator) and key emergency agencies who would lead any response in the unlikely event it was needed, and we also conduct emergency response training with key organisations. 

Together, these measures ensure that the Gordon Scheme (with Tasmania's highest capacity power station) can continue to operate safely and efficiently, contributing vital renewable energy for our state, especially through extended dry periods. It is in this role, as dam owners and operators, that we complete any approval documentation. The EPBC referral for the Edgar project reflects the comprehensive detailed design that was undertaken. Through this process, a range of solutions were considered before determining a downstream filter buttress design would deliver the most desirable outcomes.  Decommissioning any asset is a decision for the Tasmanian Government.

Thank you again for sharing your views and we welcome your ongoing engagement in this important project.

Jane

Hi Andrew,

Thank you for visiting the project page and posting a question.

First and foremost, I would like to reassure you that the risk of Edgar Dam failing is assessed as being extremely low. Nonetheless, in our role as dam managers, we complete extensive risk assessments and manage all identified risks accordingly. In this case, that includes a Dam Safety Emergency Plan and comprehensive monitoring system.

The monitoring system is similar to those installed at our other dams and ensures Hydro Tasmania is notified as soon as any potential issues arise. For Huon Valley residents, this early-warning system would trigger an immediate notification of any seismic movement, providing a maximum response time for emergency personnel.    

The Dam Safety Emergency Plan sets out how we would respond if something unusual was detected via our early warning system. This plan is managed in accordance with the requirements of the Emergency Management Act 2006 and State Special Emergency Management Plan (Dam Safety Emergencies) June 2022. Both the Act and State plan emphasise the hierarchy of incident management – and our role is to ensure appropriate state and regional organisations at every management level are fully briefed, so they may in turn plan most effectively for such unlikely events.

For the Huon Valley, the Huon Valley Emergency Management Committee plays this role, and includes representation from the Tasmanian Fire Service, Tasmania Police, Tasmanian State Emergency Service and Council. We undertake emergency preparedness scenario planning with members of this committee. In addition, all incident management documentation, including flood inundation maps, are provided to the State Control Centre and held securely on the Tasmanian Government’s Common Operating Platform which is accessible to all emergency services personnel.

Cheers

Jane

Thanks for getting in touch!

Edgar campground will be closed during works but nearby Huon and Teds Beach campgrounds (owned and managed by Tasmanian Parks and Wildlife) will be open. All 5 boat ramps at Lake Pedder, including the ramp at Edgar, will remain open.

Cheers

Jane

Hi Katie,

Thanks for visiting the project site and sharing your views with us.

Present-day Lake Pedder plays an important role in Tasmania’s energy security and the future of our nation’s transition to a renewable energy future. Lake Pedder is important because its catchment provides a significant 40 per cent of the water that flows through the Gordon Power Station which can generate up to 432 MW of electricity or approximately 13 per cent of Tasmania's annual energy needs. It is Tasmania’s largest power station in terms of both what it can power at any time, in any weather conditions and the total energy it provides in a typical year. More importantly, however, the Gordon-Pedder scheme is one of only two capable of operating during extended periods of dry and still weather, meaning that it is integral for energy security when other storages are low and wind farms cannot operate. This is particularly the case as we face a changing climate because this energy can be accessed quickly to provide critical firming (reliability) to an increasingly variable energy market. 

Our responsibility at Hydro Tasmania is primarily to generate electricity and ensure our assets operate safely and efficiently. The upcoming work at Edgar Dam is about meeting those responsibilities and completing this project will not influence any government decision about Lake Pedder's future. 

I hope this provides some context as to why we are undertaking this work. 

Cheers

Jane

Dear David,

Thanks for sharing your perspective and posing some interesting questions. There was community concern at the time of the initial impoundment, and we recognise the importance of this event in Tasmania’s history. While we can and do reflect on how to do things differently in the future, we can’t change the past. 

Safety is our number one priority and it is incorrect to claim our dams are substandard – we operate a rolling program of safety review and risk reduction that ensures all our assets meet evolving and increasingly more demanding safety standards. Scotts Peak Dam encountered some cracking, leakage, and settlement at first fill: this was resolved soon after. The other two dams that impound present-day Lake Pedder are in as-built condition and like all our assets, they are subject to safety and risk review, drawing on a range of information, site data and expert advice, including future climate modelling. Edgar Dam is considered our highest risk asset and addressing this safety issue is the driver for this project.

As you correctly point out, the fault was known at the time of construction – what has changed are evolving safety standards and our understanding of seismicity in Tasmania, the likelihood of fault movement and the potential implications for Edgar Dam. Drawing on this information, we now understand that with a simple, low-impact engineering modification, we can almost entirely remove the seismic risk. 

You ask about the fate of Edgar Pond – while we will drain, excavate, then refill the small toe pond to complete this work, Edgar Pond will not be drained or otherwise impacted. Like all other aspects of this project, any potential for impacts to Edgar Pond will be reviewed under Federal environmental legislation. 

Tasmania has a bright renewable energy future that depends on our existing hydropower assets to provide critical firming load, plus increasing wind and solar and exciting emerging technologies. The Gordon-Pedder scheme will play an intrinsic role in this future and this project will ensure we can continue to operate safely.

Thank you again for sharing your views and we look forward to your ongoing engagement in this project.

Jane

Hi Andy,

Thanks for getting in touch and sharing your views. 

We recognise that Lake Pedder holds significance for many Tasmanians and, if presented with the same set of facts in today’s world, the outcome might have been a different one. While we can’t change the past, we are committed to learning and growing as we help forge a new renewable energy future for Tasmania.

Looking after a large asset portfolio such as Hydro Tasmania’s calls for considerable forward planning – even a small maintenance job can require several years to design, source materials and arrange an appropriately skilled workforce. On top of managing these project logistics, we must also consider the outcomes of our rolling dam safety review program and commitment to continually reduce risk across our business. Given these complexities, we take a 10-year forward plan to scheduling projects, and review and adjust that schedule annually to ensure we’re always addressing the highest priority issues. The Edgar Dam Strengthening Project has been in design and preparation for more than 3 years and now we’re ready to get on and deliver this critical safety improvement. As I’ve highlighted to others on this page, this will not influence future decisions about Lake Pedder. 

With regards your comments about the management of Lake Pedder, and in particular the water level. Lake Pedder cannot be viewed in isolation from Lake Gordon – together, the two storages play a critical role in our energy market. Lake Pedder is a significant catchment and the 1.5 metres that we use represents an enormous volume of water. The operating rules for Lake Pedder that outline our minimum operating level are self-imposed by Hydro Tasmania, not UNESCO, for operational, environmental and aesthetic reasons. These rules are set out in the Electricity Supply Industry Restructuring (Savings and Transitional Provisions) Act 1995. We could opt to go below this lower level if required – but the benefit of doing so must be considered amongst a range of other factors. In the case of the 2016 energy crisis, it was considered but for various reasons, deemed not to be the best course of action.  

Thank you again for your feedback – we look forward to your ongoing engagement in this project.

Cheers

Jane

Hi Peter, 

Thanks for getting in touch. Completing this project will achieve important benefits – for more information, please refer to our new FAQ. 

You ask some important questions about the sustainability of the project. Across all our operations, our aim is to minimise our impacts and where possible, repurpose or reuse materials. 

As I explained in my response to Lindsay (on this page), the materials needed in this project must meet very technical specifications which influence quarry selection. In addition, we excluded quarries that may potentially increase project impacts, for example, sites within the TWWHA or those with biosecurity concerns. While these decisions may increase overall transport costs, they also ensure we avoid impacts which is a priority consideration.   

Across the project more broadly, we’re exploring a range of opportunities to make the works more sustainable, from recycling the concrete we remove from the dam and using pond sediments to help rehabilitate local areas, to investing in infrastructure that can be repurposed for visitor facilities once the work is done.

Thanks again for sharing your views. We look forward to your ongoing engagement in the project.

Jane