Landowners across the region should be aware that the impacts of the groundwater extraction associated with coal seam gas (CSG) development may not be limited to the Walloon Coal Measures as originally predicted in the Underground Water Impact Report (UWIR) in 2012.
The revised UWIR was released in draft in March 2016. The report concludes that bores sourcing water from the Hutton Sandstone and Precipice Sandstone aquifers may be impacted by water extraction from the CSG industry.
The aquifer known as the Walloon Coal Measures is the CSG target formation in the Surat Basin. The revised UWIR indicates that a further 64 bores sourcing water from the Walloons Coal Measures are likely to suffer a decline in water level within three years. CSG companies will need to enter into make good agreements with the owners of these bores.
However, there are some 35 water bores sourcing water from the Hutton Sandstone aquifer that are likely to be affected by a decline in water levels by over 5 metres in the long term ie. more than three years from now. The UWIR indicates that most of these bores are likely to experience a decline in water level of less than 10 metres although we are aware of bores in the Hutton Sandstone that are predicted to be impacted by more than 10 metres. In addition, there are nine bores sourcing water from the Precipice Sandstone which are predicted to be impacted in the long term.
The main reasons for these predicted impacts to the Hutton Sandstone and Precipice Sandstone are:
- the interconnectivity between the Walloon Coal Measures and the Hutton and Precipice aquifers which can vary greatly depending on the location of the water bore. Bores sourcing water from the Hutton Sandstone are particularly vulnerable to impairment because the Hutton Sandstone underlies the Walloon Coal Measures;
- the use of water bores by CSG companies in the region to fulfil their water requirements for CSG development; and
- the construction of new, replacement bores as a result of make good agreements that have been negotiated between bore owners and CSG companies following the release of the UWIR in 2012. That report identified that approximately 85 bores sourcing water from the Walloon Coal Measures would be impacted within three years. The Water Act 2000 (Qld) requirement that these bores be “made good” by the relevant CSG company has resulted in make good agreements which provide for the construction of new, replacement bores to deeper aquifers such as the Hutton and Precipice aquifers.
For those bore owners currently negotiating a make good agreement for an affected bore, it is imperative that any replacement bore be designed to accommodate future impacts from CSG industry. Any impacts that are greater than the predicted impacts in the UWIR should result in a further make good obligation on the CSG company, however, landowners should seek expert advice.
We encourage all landowners to review the status of their bore under the revised UWIR. Those bore owners with deeper bores may be impacted in the future. If you have any questions or concerns about your bore or make good agreement, please contact us for a free, no obligation discussion.