An exploration decline is an underground tunnel that will enable vehicles to travel into and drill under the ground. The tunnel will be approximately 150m deep and 600m long. There will be infrastructure near the tunnel’s entrance that will include sheds, offices, dams and rock stockpiles.

‍

Drilling underground will allow SXGC to operate more rigs and help us understand the Sunday Creek gold and antimony deposit more quickly than our surface drilling program. Developing an understanding of the geology will allow us to determine the economic viability of a mine. A decision to proceed with a mine would be made following a review of the underground drilling program.

The tunnel will allow SXGC to continue exploration drilling from underground. Our exploration license does not permit us to mine for minerals nor does it guarantee that a mining license will be approved. No processing or tailings infrastructure will be constructed as a part of the exploration tunnel.

The tunnel will be located off Hibberds Lane on SXGC-owned land. The location is indicative and the final position has not yet been confirmed. The environmental surveys that are currently underway will help us finalise the final position of infrastructure.

We anticipate construction will commence in 2026.

The project has been assessed and approved by Resources Victoria. Other government departments, including water agencies and the EPA, will also be involved in the project’s secondary approvals process.

Permitting phase - 3 months: Secondary consents from government agencies obtained.

Construction phase - 6-9 months: Site clearing. Construction of all surface infrastructure. Excavation of the box cut and construction of the portal. Construction of the decline.

Exploration phase - 4+ years: Commence underground exploration drilling. Construction of ventilation shaft – relocate ventilation fans. Commence water management. Continue surface exploration drilling under low impact exploration.

Rehabilitation phase - 1-2 years: Remove all non-earthen infrastructure. Undertake rehabilitation earthworks. Revegetate landforms. Monitor and maintain rehabilitated land until relinquishment.

As part of the exploration tunnel approval, a rehabilitation plan has been developed. At the conclusion of exploration, SXGC is required to implement the rehabilitation plan to return the land to its pre-exploration form for agricultural use. As a requirement of the retention license an environmental bond is lodged with Resources Victoria prior to the commencement of construction. The money held in this bond can be used by Government to execute the rehabilitation plan if required to do so.

Impacts on flora and fauna

Offsets for the loss of native vegetation have been secured with the purchase of 2.280 general habitat units through an accredited offset broker with the Department of Energy, Environment and Climate Action. These offsets meet the required minimum strategic biodiversity value score and are located within the Goulburn Broken CMA. No large trees will be removed. Read our ecology fact sheet here.

Will the tunnel have an impact on ground and surface water?

All surface infrastructure will be constructed more than 200m from Sunday Creek and meet Australian standards to protect water quality. We have engaged technical experts to guide us in our project design to minimise impact on groundwater. Read our surface water fact sheet here and our groundwater fact sheet here.

Will the tunnel construction affect cultural and historic heritage?

Surveys were undertaken as part of project design and all project infrastructure has been located to avoid all areas of historic and cultural heritage sensitivity.

What will I experience?

Near the tunnel entrance will be soil and rock stockpiles, a workshop, offices and dams. A ventilation shaft ensuring fresh air is circulated in the tunnel will also be built. The buildings and dams will be constructed during daylight hours. Construction of the underground tunnel  will occur 24 hours a day, seven days a week for approximately 5-6 months. Once completed, underground drilling activity will occur 24 hours a day, seven days a week. We will continue to operate our surface rigs as normal.

Will traffic on Clonbinane Road increase?

Traffic will be minimised by bussing site contractors in and out of the project in the mornings and evening. We will avoid school bus times. Some heavy vehicles will periodically access the site. All material that is excavated to construct the tunnel will be stockpiled onsite for use in rehabilitation. No material will be trucked off site. Read our traffic management fact sheet here.

Noise and vibration

Residents may hear earthmoving equipment during the construction of surface infrastructure and as material is brought out of the tunnel and stockpiled on the surface.  

Blasting will occur when constructing the underground tunnel. Tunnel blasts are relatively small and can feel like series of knocks over a period of 10-15 seconds. During blasting, residents may hear something similar to distant thunder. Blasting will typically take place during shift changes at 6:00am-7:00am and 6:00pm-7:00pm; however, it is not limited to these times andmay take place at any time within a 24 hour cycle.

It is expected there will be between 250 and 300 tunnel blasts across 5-6 months of the tunnel construction. Read our blasting and vibration fact sheet here and our noise management fact sheet here.

How will dust and emissions be managed?

We do not expect air quality to be impacted by the construction or operation of the tunnel. Modern dust suppression techniques will be employed to minimise any impact during construction. Fresh air will be drawn into the tunnel for the safety of underground workers and on cold mornings condensation may emit from the ventilation shaft. Read our air quality management fact sheet here.

How will antimony be managed?

Antimony is a naturally occurring mineral and exists in higher concentrations across much of central Victoria. While the tunnel has been designed in rock with little to no mineralisation, some of the excavated rock will contain low levels of antimony. Rocks containing higher concentrations will remain underground during the exploration tunnel construction. Read more about management of antimony in our air quality management fact sheet here.

Visual amenity

SXGC has worked to minimise the visual impact of this project. This includes positioning infrastructure behind hills and trees where possible. Some residents can expect to see some surface infrastructure including buildings, vehicle movements, dams, and rock stockpiles. Work will be done on building and lighting design and visual screening to ensure infrastructure blends into the natural environment. Read our visual amenity fact sheet here.

Bushfire risk

Our fire preparedness and response plan has been updated to reflect this change in operations and additional measures will be implemented to mitigate the risk of fire. Read our bushfire management fact sheet here.

We are always available to respond to our community’s feedback or concerns. Please contact us on the details below.