WattleAddr Property

What a mine subsidence district means

A mine subsidence district is an area of New South Wales declared because the ground there could subside over underground coal mining, whether the mining is finished, under way or still planned. Being in one is a legal status, not a finding that the ground has moved.

Districts are declared under the Coal Mine Subsidence Compensation Act 2017, which took effect on 1 January 2018. Subsidence Advisory NSW regulates development in them and handles compensation claims. Whether land is in a district is one of the matters a section 10.7(2) planning certificate must state.

Building and subdividing

Approval from Subsidence Advisory NSW is needed before starting work in a district, including building or extending a home or other structure, and subdividing land. An application can go to Subsidence Advisory directly, or through the council as integrated development. Each property in a district is assigned a surface development guideline, based on the type of mining and the predicted subsidence, which sets what a building there must be designed for.

Some minor works do not need approval, within limits:

• a carport of up to 50 m², except on land under Guideline 7;
• a deck, balcony, terrace or veranda of up to 50 m², except on land under Guidelines 1, 1A, 4, 5 or 7;
• timber or metal fences, and brick or masonry fences up to 2 m high except on land under Guidelines 4 or 5;
• an above-ground pool, spa or sauna, or a fibreglass in-ground pool, up to the 12 m maximum the list gives, except on land under Guidelines 4, 5 or 7.

A concrete in-ground pool is not on the list, so it needs approval. The full list is Subsidence Advisory NSW's Exempt Development List (April 2023).

Buying in a district

The questions are about the buildings already there. A buyer can ask Subsidence Advisory to confirm whether the structures had the approvals they needed and whether a claim has been made.

Section 23(1)(a) of the Coal Mine Subsidence Compensation Act 2017 gives a buyer a right to withdraw from a contract where a structure does not comply with Subsidence Advisory's development requirements. The Law Society has cautioned that the right is hard to use in practice, because the certificates that used to show compliance were abolished in 2019. Whether that applies to a particular contract is a question for your solicitor or conveyancer.

An owner who is paid compensation and does not repair the damage is generally required, by the deed of release they sign, to disclose that unrepaired damage to a later buyer.

Compensation for subsidence damage is paid under the 2017 Act: by the mine operator where an active mine caused it, and by Subsidence Advisory from the Mine Subsidence Compensation Fund, which coal mine operators pay levies into, where the damage comes from old workings. A structure built without a required approval is generally not eligible; compensation may be paid at Subsidence Advisory's discretion in limited cases.

What our report shows, and does not

For a New South Wales address the report states whether the address falls inside a declared mine subsidence district, from the state's district boundaries and with their currency date, and names Subsidence Advisory NSW as the authority to ask before any building work. The test is made at the address point, not across the whole lot, so land near a district boundary should be checked on the certificate.

It does not say which guideline applies, whether existing buildings were approved, whether a claim has been made, or whether the ground has moved or will. The mine subsidence map shows how many of each council's addresses are in a district, and the council pages list what else is mapped.

Check an address

Reports from $9.90 including GST, paid once. The price belongs to the jurisdiction the address is in; the check is free and tells you the exact total for your address, and which registers cover it, before you pay anything.