The Western Australian Government Department of Water and Environmental Regulation (DWER) has granted a ‘Licence to Take Water’ to Viking Mines for its First Hit Project under regulation 5C of the Rights in Water and Irrigation Act of 1914.
Ongoing works are being undertaken to assess the condition of the underground workings and contained water volumes ahead of the conclusion of the Phase 1 drilling program. Securing this licence allows Viking to utilise the water in the mine workings for specific site-based activities as well as commence the work required to apply for a works approval to discharge water from the mine into the environment.
“As part of our strategy to advance all aspects of the First Hit Project concurrently, we have applied for and received our 5C licence to take water from the First Hit Mine,” Viking’s CEO, Julian Woodcock, said.
“We are now able to utilise the mine water for the authorised activities and start the process to obtain a works approval, which is the next step to be able to dewater the First Hit mine and gain access to the workings.
“This retains optionality ahead of our results from our Phase 1 drilling program which is underway.”
Current water strategy status
To access the workings and any potential remaining mineralisation or to utilise the workings for potential deeper drilling of mineralisation, the First Hit Mine will need to be dewatered.
To achieve this, a series of government issued permits and licences are required. Obtaining the 5C licence is the first regulatory step to allow Viking to be able to dewater the First Hit Mine. Work is ongoing with the objective of obtaining necessary government approvals to be able to dewater the mine.
Since the First Hit Mine closed in 2002, the water level in the mine has returned to the natural water table, approximately 30m below surface. This has resulted in the workings up to and including the 400 level becoming flooded (Figure 1). Initial estimates indicate up to ~120,000 kilolitres of water are contained within the workings (Table 1).
A specialist survey company called Sensorem has been engaged to complete a series of LiDAR surveys of accessible underground workings to review the ground conditions, water levels positions and provide accurate volumes of the voids. As part of this work, a vertical shaft connecting the underground workings to the surface was assessed to determine the potential to pump water from the mine. The decline into the mine has been surveyed using the Hovermap® drone system down to the water level.
The 5C licence has been granted for a period of ten years (to 28 March 2031) and entitles Viking to remove up to 500,000 kilolitres of water per year from the vent raise.
The authorised activities on the 5C licence are:
- Mine dewatering
- Dust suppression
- Road maintenance
- Exploration activities
Flow metres must be installed on any pumping infrastructure and annual usage levels recorded and reported to DWER. For mine dewatering activities, a works approval process must be followed and granted before water can be discharged into the environment.
Viking has adopted an aggressive strategy to ensure that the First Hit Project can be advanced at a rapid pace in the event of positive exploration results from the Phase 1 drilling program.
The continuing activity to advance the First Hit Project include:
- Engage an environmental consultant to advise on requirements to commence with the works approval process
- Sample the water from the underground workings for preliminary testing to determine water quality as part of baseline data collection for the works approval
- Construct wireframes using historical mine survey data and Hovermap® LiDAR surveys to evaluate contained water volumes
- Engage a plumbing contractor to design and quote for pumping infrastructure options with tiered objectives for permitted water use with options to upgrade to mine if required
- Historical data search to determine recharge rates for water inflow and water balance modelling to determine pumping requirements to dewater the First Hit mine