News

UPDATED SNOWY 2.0 BUSINESS CASE REVISES NPV UPWARD TO $3BN

24/05/2024

Snowy Hydro is pleased to release the updated Snowy 2.0 business case presenting the project’s key revenue streams and value to the National Electricity Market (NEM).

Marsden Jacob Associates (MJA), a long-standing expert in modelling the NEM, was re-engaged in mid-2023 by Snowy Hydro to provide updated NEM modelling as input to the updated business case.

While the economic drivers at the time of the project’s Final Investment Decision (FID) in December 2018 have not changed, there are a number of updates and these include:

Revised total cost to complete of $12 billion and a delay to the commercial operation date to December 2028.
Delivery of an additional 200 megawatts or 10% capacity; bringing total capacity to 2,200 MW.
Increased Snowy 2.0 generation, reflecting the greater penetration of variable renewable generation (wind and solar).

The value of Snowy 2.0 to the NEM has increased since FID in December 2018, to $3.0 billion from $2.8 billion. Its completion is critical to supporting the NEM’s decarbonisation and reliability targets.

Snowy Hydro has already contracted 1.75 gigawatts (GW) of wind and solar supply which enabled 2.9GW of wind and solar projects. Snowy 2.0 will enable at least another 6GW of renewable energy through its ability to “firm” the intermittent wind and solar energy and transform this energy into cost-effective, reliable electricity supply.

The 350 gigawatt hours (GWh) of energy storage provided by Snowy 2.0 through its pump/generate function provides a meaningful step towards the 640GWh of storage identified by AEMO in its 2022 Integrated System Plan as being crucial to absorbing surplus renewable production and maintaining supply during periods of low renewable output.

Located in the NSW Snowy Mountains, Snowy 2.0 is 57% complete, with a workforce of 3,000 achieving good progress across the construction worksites.

At Lobs Hole, tunnel boring machine (TBM) Lady Eileen Hudson has excavated approximately 2km of the 6km tailrace tunnel, and world-leading TBM Kirsten is about to embark on the Inclined Pressure Shaft (IPS) excavation on a steep uphill drive of 1.6km. Stage 2 drill and blast excavation of the power station caverns continues.

When completed, the machine and transformer halls will form one of the largest and deepest caverns in the world, 800 metres underground.

More than 570,000 cubic metres of material has been excavated at the Talbingo intake – where water will exit the tailrace tunnel into Talbingo Reservoir and enter the tunnel when in pumping mode.

At Tantangara, the intake is three metres away from its fully excavated depth of 55 metres and the tunnel linking the intake and gate shaft is underway. TBM Florence is more than 850 metres into the headrace adit.

With progress slowing in very hard rock, the Snowy 2.0 project team ceased excavation by TBM Florence due to rock pinching on the machine’s shield. A specialist contractor has commenced work using high pressure water jets to remove the rock impinging on the machine’s shield.

The 28-metre wide headrace surge shaft at Marica is excavated to a depth of 85 metres, on its way to 250 metres.

The precast factory at Polo Flat, Cooma, is manufacturing concrete tunnel lining segments installed by the TBMs. More than 104,000 have been produced, along with 450 of the 7,000, nine-tonne bespoke segments for the IPS that utilise innovative force activated couplers.

The Snowy 2.0 updated business case was assessed following the revision to the project’s schedule and costs announced in August 2023.

The updated Snowy 2.0 business case is available here.

News

TBM FLORENCE UPDATE – 21 May

21/05/2024

With progress by tunnel boring machine (TBM) Florence in the headrace tunnel slowing in very hard and abrasive rock on Wednesday 15 May, the project ceased excavation by the TBM on Thursday 16 May due to rock pinching on the machine’s shield. This update on TBM operations was provided within 24 hours of the machine being stopped.

The Snowy 2.0 project team sought immediate advice from a specialist contractor with experience at other Australian projects with the same TBM situation. Today the contractor commenced work using high pressure water jets to remove the rock impinging on TBM Florence’s shield.

Timing for estimated recommencement of excavation will be determined on the successful removal of the rock.

The next TBM Florence update will be provided in the week commencing Monday 27 May.

News

TBM FLORENCE UPDATE

16/05/2024

Tunnel boring machine Florence has been ramping up excavating the Snowy 2.0 headrace tunnel, recently reaching 12 metres per day for a period.

With progress slowing in very hard rock on Wednesday 15 May, today (16 May) the Snowy 2.0 project team ceased excavation by the TBM due to rock pinching on the machine’s shield.

We are currently investigating the best way to relieve this pressure prior to recommencing excavation.

News

SNOWY 2.0 PROJECT UPDATE – APRIL 2024

01/05/2024

Snowy 2.0 is a major pumped-hydro expansion of the Snowy Scheme and at Marica, high in the Snowy Mountains, a very wide and deep surge shaft connecting to the Snowy 2.0 headrace tunnel is being built.

The surge shaft has two key purposes for the operation of a hydro power station: as a water storage and vacuum relief when the power station starts up, and to absorb the momentum of water movement within the headrace when the power station is shut down.

The Marica surge shaft is about 28 metres in diameter and is currently over 80 metres deep.

During its construction the walls of the shaft are supported temporarily by rock bolts and shotcrete and once it is excavated to its full depth of 250 metres, a permanent concrete lining will be installed from the bottom up.

We are excavating the shaft with a number of excavation methods, including using 36-tonne excavators that place loads of material into kibbles. This material is lifted out and dropped into a dump truck.

An integrated work platform and personnel hoist is in the final stages of commissioning to provide worker access now the shaft is becoming very deep.

In the latest project update, civil engineer and Snowy 2.0 project manager, Richard Clarke, details the significant work undertaken constructing Marica Trail to create a new permanent access road into the surge shaft site.

Marica Trail provides safe, all weather access for traffic, including heavy vehicles.

Building in steep terrain was challenging and required specialised rope access workers to install ground support for safety and stability.

The road has been very carefully constructed in a tight envelope. It’s 6.5 km long, with an elevation change of about 320 metres from top to bottom and multiple water crossings have been created, including over the Eucumbene River.

Over at Tantangara, drill and blast excavation to join the intake and gate shaft is underway from both structures. The transition from the intake changes shape as it is excavated to become the connection tunnel to the gate shaft.

At the same time, we have started drilling and blasting from the gate shaft to merge into the headrace tunnel alignment excavated by TBM Florence.

When completed, water will enter the headrace tunnel from the intake, on its way to the power station.

Snowy 2.0 is being engineered to deliver clean and reliable energy storage and generation for the next 150 years. The target date for commercial operation of all units is December 2028, with first power expected in the second half of 2027.

Update – Thursday 2 May

Reports today that tunnel boring machine (TBM) Florence has stopped tunnelling are incorrect.

TBM Florence remains fully operational and is now more than 800 metres into excavation of the Snowy 2.0 headrace tunnel at Tantangara. The TBM has operated successfully since its restart on 8 December 2023 and has moved through identified soft ground into hard rock.

The total distance tunnelled by all three Snowy 2.0 TBMs across the pumped-hydro renewable energy project is approximately nine kilometres.

As provided in evidence at two recent Senate Estimates hearings, Snowy Hydro has been investigating options to de-risk the headrace tunnel construction by excavating from the other end. This work remains ongoing.

News

HAVE YOUR SAY: SNOWY HYDRO LAUNCHES COMMUNITY INSIGHTS CAMPAIGN

05/04/2024

Snowy Hydro is launching a community insights campaign to better understand the social impacts of the Snowy 2.0 project.

The campaign seeks to engage and connect with community members across south-eastern NSW to gather insights, opinions, and experiences related to Snowy Hydro operations and the Snowy 2.0 project.

Through an online survey available at www.snowyhydro.com.au/haveyoursay, we invite residents, stakeholders, and interested parties to share their perspectives and help shape the future of their communities. A series of focus groups, one-on-one meetings, phone surveys and community pop-up stalls will support the online survey.

“This campaign reiterates Snowy Hydro’s commitment to transparent and inclusive community engagement,” said Snowy Hydro CEO Dennis Barnes.

“We value the input of our community members and recognise the importance of understanding their needs and concerns.”

The survey, which will be open until 5 May 2024, covers a range of topics, including community sentiment, perceptions of the Snowy 2.0 project, and suggestions for improving Snowy Hydro’s community engagement efforts. Participation is open to individuals aged 18 and above who reside or own property in the Snowy Monaro, Snowy Valleys, Towong, Bega Valley and surrounding local government areas.

“We encourage you to take part in this survey and contribute to the dialogue surrounding the Snowy 2.0 project and its impact on our communities,” added Mr Barnes.

“Your feedback will be important in informing Snowy Hydro’s social impact strategy and community engagement initiatives.”

Throughout April, Snowy Hydro representatives will engage with stakeholders in key regional towns, fostering open conversations about Snowy Hydro’s operations and future priorities. The consolidation of survey findings is planned for June 2024, with a publication of key results expected in July 2024.

For more information or to participate in the survey, please visit www.snowyhydro.com.au/haveyoursay.

Additionally, feedback or inquiries can be directed to Snowy Hydro via phone at 1800 623 776 or email at community@snowyhydro.com.au

News

SNOWY 2.0 PROJECT UPDATE – FEBRUARY 2024

28/02/2024

The new Snowy 2.0 power station will boast the latest in hydro technology, delivered by our expert subcontractor Voith Hydro. In the latest project update, Snowy 2.0 mechanical engineer Mahali Heffner details how quality assurance activities and factory acceptance testing is carried out on each power station component.

Every one of the hundreds of pump-turbine-generator components undergoes rigorous testing before it leaves the Voith factory. This is to ensure they meet high quality standards and will operate reliably when the power station is switched on.

A team of Snowy Hydro and independent assessors recently conducted mechanical and hydraulic dimensional checks on the first Snowy 2.0 runner at the Voith factory in Shanghai, China.

The runner is the heart of a hydro turbine – it’s the rotating element that drives the generator to produce power.

Acceptance testing includes checking the profile of the blades and surface examinations.

Dye penetrant testing is used to identify imperfections on the surface of the 31 tonne, 4.2 metres-wide runner. We spray on a red dye, clean it and apply the developer. If imperfections are present, the dye will make them visual.

Snowy Hydro and contractor Future Generation Joint Venture (FGJV) work with Voith and other subcontractors on a range of quality assurance activities as part of the multi-stage manufacturing process.

At Lobs Hole in the Snowy Mountains, power station components including turbine guard valves, spiral cases and draft tube liners are being progressively delivered to site.

Meanwhile, deep underground, excavation of the machine hall and transformer hall cavern crowns have been completed and we’ve almost finished the final side slashing to widen the structures. Drill and blast works are also continuing in the cross passages and tunnels that are an important part of the power station complex.

At the other end of the project at Tantangara, the intake is really starting to take shape. We are well into stage two of the excavation, now approximately 49 metres below ground level and approximately six metres to go.

We map the cut face to determine what rock support is required and then after the design is confirmed, rock bolts and shotcrete are installed. It’s exciting to see the shape of the transition from intake to tunnel, with the canopy tube rock support in the intake face forming an arch above the tunnel entrance.

Drill and blast of the tunnel excavation is scheduled to start soon and the first milestone target will be to link up the intake with the gate shaft.

News

SNOWY 2.0 PROJECT UPDATE – JANUARY 2024

31/01/2024

Deep underground at Lobs Hole in the Snowy Mountains is the heart of Snowy 2.0, the pumped-hydro expansion of the mighty Snowy Scheme. It’s where we’re building a huge power station complex that will house equipment capable of generating 2,200 megawatts of renewable energy.

In this month’s update we’re celebrating a major power station construction milestone – the breakthrough blast of the machine hall cavern crown.

With excavation of the crown – or ceiling – of the cavern taking place from both ends, the final three metres of rock are drilled and charged with explosives according to a precise blast plan.

The tunnels are cleared and the shotfirer arms the electronic blasting system which uses a unique electrical pulse to initiate firing of the explosives.

According to Snowy 2.0 project director Dave Evans, the machine hall achievement signals further progress after the recent transformer hall cavern crown breakthrough and restart of tunnel boring machine Florence in the headrace tunnel at Tantangara.

“These milestones are only possible with the whole team working together as one, whether they are subcontractors like Orica, the company managing underground blasting operations, or the lead contractor Future Generation and Snowy working so closely together.”

To see the latest Snowy 2.0 project’s statistics, view the fact sheet here.

As the underground drill and blast works continue, the manufacturing of major hydropower components for Snowy 2.0 is also well underway.

Snowy Hydro senior quality engineer Victor Teo is based for part of the year in Shanghai, where Voith Hydro – the company producing major power station equipment for Snowy 2.0 – has a large facility.

He also travels to nearby cities including Zhuji and in his quality and compliance role, participates in factory acceptance tests and hold point inspections for components being fabricated by subcontractor Shenke such as the draft tube liners and cones, and the huge stator frames.

The draft tube liners funnel water into and out of the power station turbines and are comprised of six segments. They are 4.6 metres high, 30 metres long and weigh 40 tonnes when assembled.

The six stator frames that house the generator are fabricated in two halves and are welded together for a total weight of more than 400 tonnes.

Snowy Hydro has an integral part to play in establishing high standards of equipment manufacturing, which meet the engineering requirements for our critical Snowy 2.0 project infrastructure.

News

BREAKTHROUGH MILESTONE FOR SNOWY 2.0

05/01/2024

Snowy Hydro is pleased to announce another major achievement for the Snowy 2.0 pumped-hydro project, with the breakthrough of the final three metres of the power station’s 223-metre long transformer hall cavern crown.

The Snowy 2.0 delivery team began excavating the transformer hall and machine hall caverns in June 2023. The Snowy 2.0 power station will be located approximately 800m underground at Lobs Hole in the Snowy Mountains. When completed, the machine hall will be 251 metres long and 52 metres high and the transformer hall 223 metres long and 46 metres high. Together they will form one of the largest and deepest caverns in the world, big enough to fit the Sydney Opera House inside.

Precise drill and blast methods are used to profile the curved cavern crowns (or ceilings) and break up the rock, which is mucked out and followed by surface scaling to remove any remaining loose rock. The exposed solid rock face is then supported with rock bolts and shotcrete. The excavation sequence of the cavern crowns is carefully planned and executed, as the rock mass relaxes and moves inwards as the excavated void increases. These movements are expected and are closely monitored during the process.

So far, about 17,000 cubic metres of material has been excavated from the central heading of the transformer hall cavern crown. The heading has been advanced in 3-4 metre rounds from either end of the cavern for a total of 77 blasts.

The machine hall cavern crown breakthrough will take place in coming weeks, and widening of both cavern crowns, known as side slashing, is ongoing and planned for completion in coming months. Excavation of both power station caverns is set to continue through 2024.

The breakthrough of the transformer hall cavern crown represents another important milestone for the Snowy 2.0 pumped-hydro project that will significantly expand the existing Snowy Scheme and will provide an added 2,200 megawatts of on-demand power and 160 hours of large-scale renewable energy storage for the National Electricity Market.

Snowy Hydro CEO Dennis Barnes said: “The breakthrough of the transformer hall cavern crown is a really pleasing milestone for the Snowy 2.0 team, reinforcing that we’re making good progress with our underground drill and blast excavation activities. We are well on our way to delivering the largest single project that will help ensure Australia’s secure and reliable transition to renewable energy.”

News

NEW MAJOR PARTNERSHIP – SNOWY VALLEYS SCULPTURE TRAIL

23/10/2023

Engineering meets art on a grand scale, with Snowy Hydro CEO Dennis Barnes today announcing a new major sponsorship of the Snowy Valleys Sculpture Trail (SVST).

The SVST partnership includes funding from Snowy Hydro for seven new sculptures and a school education program aimed at delivering artist-led sculpture workshops to more than 1,500 school children in the Snowy Valleys Region.

“Snowy Hydro is proud to take on the role of Major Partner of the Snowy Valleys Sculpture Trail, a partnership that underscores our long-term, ongoing commitment to the local communities we operate in,” Dennis said.

“The Snowy Valleys Sculpture Trail is celebrated for its eye-catching outdoor art installations throughout the picturesque Snowy Valleys region and our support will enhance the trail’s reach, making it more accessible and engaging for both residents and visitors alike. We hope it will also draw more tourists to the region, thereby benefiting the local economy.”

The seven new Snowy Hydro-funded sculptures will be leased and installed over the next two years adding to the 35 existing artworks located between Adelong and Tooma, including the historic towns of Batlow, Talbingo and Tumbarumba.

A key element of Snowy Hydro’s exciting partnership with SVST is the School Education Program. This program will bring artist-led sculpture workshops to 14 primary schools in the Snowy Valleys Region, along with two schools in Cooma and the Adaminaby Public School. Students will have the opportunity to immerse themselves in the world of art, creativity, and engineering through the added participation of Snowy Hydro engineers in the workshops.

Dennis emphasised the importance of the program, which aligned with Snowy Hydro’s education focus on science, technology, engineering and maths and engaging young people in activities that spark future careers.

“We believe that art and engineering go hand-in-hand, which is why they’re both core parts of our Next Generation Education Academy activities. Sculptures, like our hydroelectric projects, require a high level of engineering skill and creativity.

“By exposing students to these artist-led workshops, we hope to inspire the next generation of engineers and artists right here in our local community.”

Snowy Valleys Sculpture Trail Founding CEO & Artistic Director David Handley expressed that:“It has been a humbling privilege to work with the local communities across the Snowy Valleys to create the Snowy Valleys Sculpture Trail as one of the most important cultural projects in regional Australia.

“Snowy Hydro’s sponsorship means we are able to continue to deliver what we set out to do in providing the School Education Program for free to thousands of students across the Snowy Valleys, while building on the sculpture trail to offer visitors another reason to come back again and again to enjoy this stunning part of Australia.”

Snowy Hydro looks forward to working closely with the Snowy Valleys Sculpture Trail team and schools across the region to foster a deeper appreciation for art, engineering and innovation.

News

SNOWY 2.0 PROJECT UPDATE – SEPTEMBER 2023

05/10/2023

Following the recent announcement of the Snowy 2.0 project reset, the Snowy Hydro and Future Generation contractor teams are now a single team, working in close collaboration to achieve full commercial operation by December 2028.

The Snowy 2.0 Project Team is focused on excellent environmental outcomes while maintaining all-important safety principles. Safety is the number one priority for Snowy Hydro and core to the company’s values. High expectations for the management of all safety risks extend across the Snowy 2.0 project, without compromise.

Snowy 2.0 is critical to Australia’s transition to a low-carbon economy and when complete it will have broad-scale environmental benefits. Consistent with its responsible operation of the Snowy Scheme in Kosciuszko National Park for almost 70 years, Snowy Hydro is equally committed to minimising potential impacts from Snowy 2.0.

SAFETY PERFORMANCE

– As at September 2023, the project’s 12-month rolling TRIFR (Total Reportable Injury Frequency Rate) is 2.97, below the target of 4.0.**
– There has been a reduction in recordable and serious incidents on the project, with a focus on planning and a coordinated approach to safety management.
– Snowy 2.0 works closely with Comcare and SafeWork NSW and will continue to incorporate lessons learned and findings from the regulator into operational practices.
**Calculated per million hours worked. Total hours worked to end September 2023: >17.7 million.

Construction of Snowy 2.0 will temporarily impact less than 0.1% of the park with any short-term unavoidable impacts rehabilitated throughout the project, in accordance with environmental project approvals. This includes around $100 million provided by Snowy Hydro to the offsets program for Kosciuszko National Park. Once operational, Snowy 2.0’s footprint within the park will be only 0.01%.

ENVIRONMENTAL PERFORMANCE

– 4 independent audits of the Snowy 2.0 project undertaken since project commencement.
– 1,500 hours spent annually to proactively monitor the 163 biodiversity sites.
– More than 200 kilograms of native seed collected over three years for rehabilitation activities.
– 27 heritage site excavations and more than 35,00 indigenous artefacts salvaged and currently being documented, adding to the history of the Snowy Mountains Indigenous people.

In this month’s update from the main worksite at Lobs Hole, Project Integration Manager Paul Smith recaps progress to date with over 40 per cent of Snowy 2.0 now complete, including:

Excavation of the 2.85 kilometre main access tunnel, lined with almost 13,000 locally manufactured concrete segments.
Excavation of the 2.9 kilometre emergency, cable and ventilation tunnel.
Major upgrade of Ravine Road, the steep and winding 15 kilometre access road into Lobs Hole.
Infrastructure to support construction including the main yard workshops, worker campsites and more than 50 kilometres of access roads across three main worksites at Lobs Hole, Marica and Tantangara.

Excavation is underway of the huge 250 metre-long underground power station cavern and the tailrace tunnel, and TBM Kirsten is being modified to excavate the world-leading inclined pressure shaft. Drill and blast to create 11 cross passages and construction tunnels continues.

Above ground, there is plenty of activity across all sites. Lobs Hole Surface Works Project Manager Steve Lee helps ensure the Snowy 2.0 project is delivered in a safe and timely way, and to the quality standards and requirements of Snowy Hydro.

Surface works refers to a broad mix of activity such as haulage of spoil, maintenance of site roads, environmental controls, main yard area activity, office facilities and directional drilling, as well as the Talbingo intake build.

Latest progress on site includes Stage 2 earthworks with a recent blast covering an area of 4,500 square metres. About 10,000 cubic metres of material is being removed as the excavation of the 104-metre-high intake continues.

Snowy 2.0 is the largest renewable energy project under construction in Australia and will provide crucial deep storage central to Australia’s renewable transition. When complete, Snowy 2.0 will deliver 2,200 megawatts of dispatchable generation.

News

SNOWY 2.0 PROJECT UPDATE – JUNE 2023

26/06/2023

In the June update of the pumped-hydro expansion of the mighty Snowy Scheme, Snowy 2.0’s Alex Woschitzka explains construction progress at the massive Talbingo and Tantangara intakes. The project’s Quality Coordinator also checks in on the transformation of a narrow fire trail through steep terrain into a road suitable for heavy vehicles.

Significant progress has been made at the Talbingo intake, where water will exit the tailrace tunnel when Snowy 2.0 generates power. This is also where water enters the tunnel for pumping.

Construction teams have moved more than 310,000 cubic metres of earth to date, about half the total amount that will need to be moved. More than 24,000 metres of rock bolts have been installed and 8,300 square metres of shotcrete sprayed to support the wall.

As part of quality assurance, the shotcrete must be tested for compressive strength. Samples are taken from the truck and also cored from the face to ensure it meets the intended strength requirements. For the rock bolts, pull-testing is conducted to ensure they have been correctly installed, and meet the design and quality requirements.

When completed, the total height of the Talbino intake excavation will be 104 metres, with about 31 metres of that below the water level. The concrete intake structure will be an impressive 50 metres in height.

Construction is well underway on an internal access road through mountainous terrain. With the help of Snowy 2.0 subcontractor Leed, a narrow fire trail will be widened into a six-kilometre road to enable heavy vehicles to access a rock emplacement area on Talbingo Reservoir.

Works began from both ends across very challenging terrain, achieving a major milestone recently when the two pioneering fronts joined across the Middle Creek cliffs. A temporary bridge with a 36-metre span has been installed across Middle Creek and is capable of supporting a fully-loaded 80-tonne dump truck.

In another milestone achieved in June, stage one earthworks have now been completed at the Tantangara intake. The first stage involved excavation of about 205,000 cubic metres of earth with a further 78,000 cubic metres of drilling and blasting earthworks expected in the next stage.

To support the excavation, more than 18,000 metres of rock bolts have been drilled and installed, and approximately 6,100 square metres of shotcrete sprayed. The excavation is currently about 26 metres deep and will be extended to a total depth of 55 metres.

Tantangara intake is where water will enter the headrace tunnel when the Snowy 2.0 power station is in generation mode. When in pumping mode, water will exit through the intake and fill Tantangara Reservoir.

News

SNOWY 2.0 PROJECT UPDATE – MAY 2023

30/05/2023

May was a milestone month for the Snowy 2.0 team with the completion of the emergency, cable and ventilation tunnel, or ECVT – another vital step in the construction of Snowy Hydro’s new pumped-hydro expansion megaproject.

Snowy 2.0 senior project manager Rodd Brinkmann explains the next stage of the project from his base at Lobs Hole, as preparation for excavation for the underground power station cavern gets underway.

The ECVT is a 2.93 kilometre tunnel that runs adjacent to the main access tunnel and provides alternate access to the site of the underground power station. Tunnel boring machine (TBM) Kirsten recently completed excavation of the ECVT and will soon start tunnelling the inclined pressure shaft. This very steep shaft links to the headrace tunnel from Tantangara Reservoir.

TBM Kirsten will need to undergo modifications to excavate the 25-degree incline, including installation of a screw conveyor to extract excavated rock from the cutterhead to a sandwich conveyor system. With such a steep incline, construction of the 1.45km shaft with its concrete segment-lined tunnel, will be a world first.

In the main access tunnel, or MAT, construction of cross passages and construction access tunnels is well underway with 850 metres of drill and blast tunnel excavation completed. Of the five cross passages linking the MAT and the ECVT, two are fully excavated and waiting on breakthrough into the ECVT. Key construction tunnels are also being excavated to provide access to the machine hall, transformer hall and the top of the tailrace surge shaft.

Workers have reached the main cavern areas from both ends and will soon commence excavation and support of the cavern crowns or ceilings of the power station halls. The excavation sequence of the cavern crowns is critical, as the in situ rock mass will relax and move inwards as the excavated void increases. These movements will be closely monitored during the process. Geotechnical drilling and plate load tests will measure and confirm the characteristics of the rock geology around the power station.

Dynamic 3D models of the power station caverns are also being used. 3D models are created using digital engineering to transform 2D design drawings and are displayed in the state-of-the-art immersive theatre at Snowy Hydro’s Discovery Centre in Cooma, where Snowy 2.0 engineers can collaborate with power station design experts from around the world. Once construction is complete, the detailed 3D models will be a valuable tool for asset maintenance.

With so much activity in the tunnels, the current Snowy 2.0 underground workforce will increase by another 200 people in the coming months.