Changes to mine subsidence districts

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Revised mine subsidence districts

Mine subsidence districts (districts) across New South Wales were updated in 2017 to better reflect areas where there is potential for subsidence. 

The changes mean that some districts have been reduced in size, some extended and a number of new districts have been established.

Areas have been removed from districts where there are no or minimal mine subsidence risks. This includes areas where mining was planned but did not eventuate. Development in these areas will no longer require SA NSW approval.

New and extended districts have been created where mining is planned or development has progressed over old mine workings. Developments within the expanded districts will require SA NSW approval. This will help protect homes from damage by ensuring sound structures are built in potential subsidence zones.

SA NSW will continue to manage all mine subsidence safety matters across New South Wales through its 24 hour emergency hotline [1800 248 083]. Any home or structure that is damaged as a result of mine subsidence in New South Wales is eligible for compensation provided it has been constructed in accordance with any applicable approvals.

The changes follow a comprehensive review of all districts undertaken by SA NSW. Proposed changes were placed on public exhibition as part of the review and the updated districts reflect feedback from a range of stakeholders.

Frequently Asked Questions
1. What is mine subsidence?

Mine subsidence is the movement or vibration of the ground following the extraction of coal. Sometimes after coal is extracted from beneath the ground, the above soil and rock can fall and fill the void left behind causing movement of the ground surface.

Mining does not always cause subsidence and there are many examples where mining has occurred without causing any movement of the land surface. When subsidence does occur, the impacts can vary depending on a number of factors including how deep the mine workings are, how the coal was extracted, and the geology of the land.

Subsidence can occur without any effect on buildings and structures, however, sometimes damage may occur. Damage to structures can range from hairline cracks and jamming doors to structural damage. Generally, buildings damaged by subsidence remain safe and people can continue to occupy them until they are repaired.

Any home or structure that is damaged as a result of mine subsidence in NSW is eligible for compensation through SA NSW provided it has been constructed in accordance with any applicable approvals. Please see questions 3, 10 and 11 for more information about applicable approvals.

Some areas over old shallow mining can result in subsidence in the form of a hole in the ground surface; this is known as a ‘pothole’. Most potholes are relatively small, however, it is important that they are all treated with caution and any safety issues are promptly addressed. SA NSW attends to all emergency subsidence safety issues, including potholes, through its 24 hour hotline – 1800 248 083.

2. How are subsidence safety issues managed?

Safety is the highest priority for SA NSW. A 24 hour emergency hotline (1800 248 083) is available to all members of the public to report subsidence issues presenting safety or serviceability concerns, including pothole subsidence. This service operates both within and outside of mine subsidence districts (districts).

Once notified of a subsidence safety or serviceability issue, SA NSW coordinates an immediate response to ensure the affected area is made safe. SA NSW may make the area safe by restricting access to the site of the subsidence until final rectification work is completed.

In addition to its emergency service, SA NSW also controls development within districts to help protect homes and structures from potential subsidence damage. Developed areas are more likely to have large and complex structures which can present greater safety risks if impacted by mine subsidence; therefore, by specifying the construction conditions, SA NSW can help keep structures safe.

3. What is a mine subsidence district?

A district is a land zoning classification administered by SA NSW under the Coal Mine Subsidence Compensation Act 2017 to help protect homes and other structures from potential mine subsidence damage.

Districts are proclaimed in areas where there are potential subsidence risks from underground coal mining that has occurred or may take place in the future. Some districts are proclaimed over areas that have no future proposals of mining but were mined beneath many years ago. Some areas within districts may be within an active mining lease and may be mined beneath in the future. All potential mines are considered by the NSW Department of Planning & Environment and need to go through a rigorous approval process.

SA NSW regulates development within districts to ensure new or altered homes and structures are built to an appropriate standard that reduces the risk of damage should subsidence occur. Development applications within districts require SA NSW approval in addition to other relevant approvals. Property owners are required to submit applications for proposed building improvements or subdivisions to SA NSW for approval prior to undertaking any work.

SA NSW may place conditions on any proposed development to help protect it from potential subsidence damage and ensure the safety of the community. In most cases, SA NSW's development requirements for standard residential development are consistent with the Australian Building Code and do not result in increased construction costs or requirements.

4. Why has Government updated mine subsidence districts?

The Government has updated districts following the first collective review in over 20 years. The review identified areas where changes, including the removal of some existing areas from districts and the proclamation of new areas, were necessary to ensure that districts accurately reflect areas where mine subsidence could potentially occur.

Any building or structure within a district that has been revoked will still be eligible for compensation in the very unlikely case it is damaged by mine subsidence, provided it has been constructed in accordance with relevant approvals. SA NSW has excluded areas from districts only where it is satisfied that there is now minimal risk of mine subsidence. This includes areas that were previously included in a district due to anticipated mining activity that did not eventuate. The key difference for property owners in those areas that have been revoked from a district is that they no longer need to obtain approval from SA NSW to build or subdivide.

A number of new areas have been proclaimed within a district where development has or will take place and there may be potential subsidence risks. These areas need to be included within districts so that SA NSW can help protect homes and structures from potential subsidence damage through regulation of development.

SA NSW is committed to ensuring districts remain up to date and will now review districts every five years. There will also be scope for out of session reviews as necessary.

5. What are the changes to mine subsidence districts?

Districts have been revised to accurately reflect areas where there are potential mine subsidence risks.

A number of districts have reduced in size with significant areas revoked to reduce unnecessary development regulation where there are no or minimal mine subsidence risks. These areas include

those that have not been mined beneath as well as areas where there is deep mining that does not present subsidence risks.

New areas have been added to districts where mining may occur in the future or development has progressed over old mine workings. Development in these areas will now require SA NSW approval to ensure that buildings and structures are constructed in a way that helps to protect them from potential subsidence damage. In most cases, SA NSW’s construction requirements for standard residential development are consistent with the Australian Building Code and do not result in increased constructions costs or requirements.

6. Are there safety concerns for properties within districts?

SA NSW is committed to ensuring public safety. The emergency hotline (1800 248 083) is available if people have immediate mine subsidence safety issues that require attention.

It is important to know that the inclusion of a property within a district does not mean it will be mined beneath. Similarly, just because a property has been mined beneath it does not mean that it will be impacted by subsidence.

Mine subsidence can be caused by either inactive or active mining. Historically, underground mines in NSW extracted coal through bord and pillar mining methods. Coal extraction may have occurred over 150 years ago but supporting structures were left after mining. There are many homes built over these old mines that will never be impacted by subsidence as the mine workings are considered stable.

Occasionally, parts of old mines may collapse causing subsidence. A range of factors, including water inundation, may have caused the old mine workings to deteriorate over a long time. Subsidence caused by these old mines is generally localized and only affects a single property. Sometimes an entry point to an old inactive mine will subside resulting in a pothole; it is in these rare circumstances people should report the matter to SA NSW’s 24 hour emergency hotline on 1800 248 083.

Most underground coal mines operating in NSW today use longwall mining methods. Subsidence from longwall mining occurs within two to five years following the extraction of coal. This means there are no long-term risks of damage from subsidence. Due to the depth required for longwall mining in NSW there is no risk of potholes forming in these areas.

In most cases, mine subsidence damage to houses or structures occurs when parts of underground mines collapse. Typically, mine subsidence damage occurs unnoticeably over a period of time as the ground beneath settles. Buildings damaged by subsidence generally remain safe and people can continue to occupy them until they are repaired.

Proclaiming areas within districts enables SA NSW to reduce and sometimes eliminate the risk of mine subsidence damages by overseeing the type of development such as the type of building to be constructed. This is why it is important that development within proclaimed districts is considered by SA NSW.

7. Are there safety concerns for revoked properties?

No. Mine subsidence can only occur in areas where there has been mining. Most of the areas that have been excluded from districts have never been mined beneath and additional regulation of development from SA NSW is not necessary.

8. Will my property still be eligible for compensation?

Yes. Any home or structure in NSW, irrespective of whether it is in a district, is eligible for compensation if it is damaged by mine subsidence provided it has been constructed in accordance with any applicable approvals.

9. Will the changes to districts impact property value?

There are many examples of property markets within districts that have not been impacted. For example, the whole of the central Newcastle is within a district and there is a great demand for property within the area. There are also many areas within districts where property prices are comparable to surrounding areas that are outside of a district.

10. How will this affect my planned development?

If your development application was approved by Council prior to 1 July 2017, you will be able to carry out the development as planned and it will be eligible for compensation for mine subsidence damage.

Any proposals being considered by Council from 1 July 2017 will be referred to SA NSW by Council. SA NSW may place conditions on the development to help protect it from potential subsidence damage.

SA NSW aim to process 95% of low complexity, residential development applications within five working days. Some of the complex proposals require additional studies and consideration which may require more time.

If you have any questions about how the changes to districts will impact planned development, you can contact SA NSW on (02) 4908 4300 or at sa-districts@finance.nsw.gov.au.

11. Are there additional costs to build within districts?

SA NSW regulates development within districts to ensure buildings and structures are constructed in a way that helps to protect them from damage should subsidence occur. In most cases, SA NSW’s development requirements for standard residential development are consistent with the Australian Building Code and do not result in increased construction costs or requirements.

SA NSW has set development guidelines to assist landowners who want to build or subdivide within a district. The guidelines set out the requirements for building on or subdividing a property based on potential subsidence risks. Different guidelines may apply to different areas within a district. Guidelines may include requirements related to the nature and class of any development on a property, the size, height and location of new structures, and the use of certain building materials and construction methods. Landowners can request a copy of the guidelines that apply to their property here.

Applications for proposed development that do not comply with the mine subsidence development guidelines will be considered by SA NSW on merit. SA NSW may place conditions on the development to help protect the proposed building or structure from potential subsidence damage.

In the past, some Councils have sought advice from SA NSW on appropriate development regulations in areas outside of districts where there were potential mine subsidence risks; therefore, it is possible that SA NSW development regulations for areas that have recently been included within a district will be consistent with current Council regulations.

Some large commercial development proposals over old mines can present subsidence risks and as a consequence additional development costs may result. Large and complex development proposals are considered by specialist engineers within SA NSW. In some cases, SA NSW may require developers to eliminate the risk of subsidence by filling the old mine with concrete.

12. How do I lodge a development application with SA NSW?

If you are planning to build or subdivide within a district, you must obtain development approval from SA NSW prior to commencing work. Applications can be lodged as an Integrated Development through your local Council or directly with SA NSW here.

13. How can I obtain further information?

If you would like further information regarding the changes to districts, please contact SA NSW on (02) 4908 4300 or at sa-districts@finance.nsw.gov.au.