Safety and subsidence emergencies
Learn about mine subsidence and how to report safety issues.
What to do if you have a subsidence emergency
If you suspect that you have a subsidence emergency at a property or have found a subsidence hole, you should keep away and immediately report it to Subsidence Advisory’s 24 Hour Emergency Hotline on 1800 248 083 who will coordinate a response. If there is an immediate threat to life or property call Triple Zero (000).
Thousands of people live in areas where there are underground mines across NSW. If there has been underground mining in an area, it does not mean it will be impacted by subsidence.
In many areas, old mine workings are considered stable and are unlikely to cause subsidence. When subsidence does occur, it generally happens unnoticed as the mine workings deteriorate over time.
Check the NSW Planning Portal to find out if you live in an underground mining area
Safety is the highest priority for SANSW. A 24 Hour Emergency Hotline on 1800 248 083is available to all members of the public to report subsidence safety issues. This service operates both within and outside of mine subsidence districts.
Once notified of a subsidence safety issue, SANSW coordinates an immediate response to ensure the affected area is made safe.
What is a subsidence emergency?
A subsidence emergency can be caused by the movement of the ground after underground coal mining. After coal is extracted from beneath the ground, the land above can sink and fill the hollow mine workings. This can cause tilts and strains on the ground surface.
Most active underground coal mines operating in NSW today use longwall mining methods. Longwall mining is a gradual process, signs of subsidence damage can include jamming doors or windows. Due to the depth required for longwall mining in NSW there is no risk of potholes forming in these areas
Subsidence caused by old non-active mines in NSW is generally localised and only affects a small area. In rare instances, collapses in the old mine workings result in holes in the ground surface known as subsidence holes or ‘potholes’.
A subsidence hole (also known as a pothole) is a hole in the surface of the ground that can appear because of mine subsidence from underground coal mines at a shallow depth. A subsidence hole would only occur in a non-active mining area.
- vary in size and appearance
- can look similar to other types of holes in the ground
- can range from fist size to much larger
- may appear as an open hole or a depression in the ground.
Some subsidence holes may look small and insignificant on the surface but open up into a much larger cavity beneath the ground. This means that the ground surrounding subsidence holes can be unstable and may easily collapse so it is important to keep a safe distance.
Subsidence holes can also contain hazardous gases from old underground mines that can cause serious harm if inhaled. These dangerous gases may not be visible and only be detectable with the right equipment. It is important not to approach the hole and immediately report it to SANSW on 1800 248 083.
Subsidence holes are localised incidents. This means they can occur on a property without impacting neighbouring areas.
What causes subsidence holes?
A subsidence hole may appear when parts of an old underground mine collapse. Subsidence holes typically occur in areas where old mine workings are very shallow. In NSW, this is generally limited to the Newcastle, Hunter, Lithgow and Gunnedah regions.
Most active underground coal mines across NSW today use modern mining methods to extract deep coal, such as longwall mining. Longwall mining at depth does not create a risk of holes.
A safety or serviceability issue due to mine subsidence can range from shifted fences and jammed doors to more significant structural issues. Generally, buildings damaged by mine subsidence remain safe and can be used until they are repaired.
It’s important to be aware that damage to homes and structures could be caused by factors other than mine subsidence such as reactive soils, the roots of nearby trees and poor building practice.
If you have an urgent safety or serviceability concern, please immediately report it to Subsidence Advisory’s 24 Hour Emergency Hotline on 1800 248 083 who will coordinate a response.
If you believe your property has been damaged as a result of mine subsidence but the issues do not pose an urgent safety of serviceability concern, please lodge a claim for compensation on our online portal.
Maurie Mole is Subsidence Advisory’s mascot. Maurie has been educating communities living in mine subsidence areas about the dangers of subsidence holes for over 30 years with his important safety message:
‘If you see a hole, don’t think you’re a mole – walk in the opposite direction and report your detection’.