Locating and avoiding underground infrastructure

General safety guidelines

Simple steps to take before breaking ground to ensure the safety of people and assets: 

Always obtain plans first

Use Before You Dig Australia (BYDA) service to access free underground asset plans. These plans will help you identify assets in proximity to the work and the relevant network operators to contact for further information.

Verify underground assets

Property boundaries and fence locations aren’t always a reliable predictor of a utility location. While plans provide guidance, they may not pinpoint exact locations. You should always confirm asset positions.

Plan to use safe excavation techniques

Carry out ‘potholing’ (hand digging using non-conductive tools or hydro vacuum extraction) before mechanical excavation near underground assets. Maintain minimum clearance distances required by the asset owner.

Overhead cable safety

Don’t neglect other risks overhead. States have specific codes of practice which advise on separation distances and clearances to be maintained when operating vehicles and mobile plant such as excavators. BYDA operates a free overhead cable planning tool Look Up and Live via www.lookupandlive.com.

Emergency contact information

Have contact details on hand. If damage occurs, immediately notify the affected utility provider. In life-threatening situations, call 000.

Working near specific infrastructure

After identifying assets in the area, here are some general precautions to take for specific underground infrastructure.

Gas pipelines 

Contact the gas pipeline operator

Some high-pressure gas pipelines require direct approval from the asset owner before any work begins. A BYDA response will provide contact details for gas providers such as APA Group, Jemena, AGN, or ATCO Gas. An Authority to Work Permit (ATWP) may be required. 

Obtain appropriate approval for the works:

For small, low-pressure gas mains, BYDA approval may be enough. For high-pressure transmission pipelines, explicit approval and supervision are required. 

Hand digging (potholing) is mandatory

Before using any mechanical excavation, the pipeline must be physically located using hand digging or hydro vacuum excavation.

Preventing damage requires mandatory clearances

No work within easement without approval.

Establish if ‘site watch’ is required

Some gas operators require a representative to be on-site to monitor excavation near critical gas assets. 

Emergency procedures

If a gas line is damaged, you must immediately notify the asset owner and follow emergency protocols.

Gas emergency contact: 1800 GAS LEAK 1800 427 532

Water pipes

Depth considerations

• Minimum cover varies but is typically 450 mm to 750 mm. 
• Some water mains may be shallow; always verify depth before excavation.

Protecting water assets

• Use a locator to avoid striking pipes with mechanical equipment.
• Damaged water pipes can cause flooding and contamination risks.

Electrical cables

Safety measures

• Identify electrical pits, marker plates, warning tapes and conduit indicators that signal underground power.
• Use non-conductive tools when locating cables.
• If a cable is damaged, do not touch it—contact the power company immediately.

Sewer lines

Depth considerations

• Varies from 600 mm to over 3.0 m depending on location.
• Shallow sewer pipes are common in residential areas.

Preventing damage

• Damaging a sewer line can cause health risks and environmental hazards.
• Always locate and verify sewer connections before excavation.

Telecommunications

During any construction activity, Telstra requires operators to maintain the following clearances to prevent damage:

• 1.0 m of actual location for mechanical excavators, jackhammers / pneumatic breakers, boring and tree removal.
• 2.0 m of actual location when using in-line, horizontal and vertical boring.

When these distances cannot be maintained, the person responsible needs to contact the Network Integrity Help Desk on 1800 653 935 (7.00am – 7.00pm AEST) and discuss alternative protection options.

Depth considerations

• Footway minimum 450 mm.
• Roadway minimum 450 mm at drain invert and 600 mm at road centre crown.

NBN Co suggest when carrying out any works in the vicinity of nbn™ facilities, maintaining clearance of:

• 300 mm when laying assets inline, horizontally or vertically. 
• 500 mm when operating vibrating equipment, for example: jackhammers or vibrating plates.  
• 1.0 m when operating mechanical excavators.

State-specific guidelines and contacts

Before You Dig Australia (BYDA) operates in all states and territories.

Queensland

Asset owners in Queensland include:

• APA Group Gas Networks
• DBYDNetworksAPA@apa.com.au for Northern Territory, South Australia, Southern New South Wales and Victoria
• PermitsQLD@apa.com.au for Queensland and Northern NSW (including Tamworth)
• Energex QLD and Unitywater South.

New South Wales

In NSW, asset owners such as Sydney Water, Telstra, and local councils provide BYDA responses. Always check local clearance distances and confirm asset locations using the BYDA service and certified locators before beginning excavation.

Victoria

In Victoria, consult with asset owners like Melbourne Water, CitiPower, and other local utilities. Ensure that all excavation work adheres to the minimum depth and clearance requirements as specified by local guidelines. Obtain and review utility plans before proceeding.

South Australia

South Australia’s guidelines require strict adherence to asset owner instructions from bodies such as SA Water and ElectraNet. Always verify utility plans and clearance distances and confirm with the relevant authorities before starting work.

Western Australia

In Western Australia, guidelines provided by Water Corporation and Western Power must be followed. Obtain the latest asset maps and confirm clearance requirements to ensure safe excavation near critical infrastructure.

Tasmania

Tasmania’s utilities, including TasWater and TasNetworks, provide state-specific excavation guidelines. Ensure you secure the necessary plans and verify on-site conditions with local asset owners prior to commencing any excavation work.

Northern Territory

In the Northern Territory, asset owners such as Power and Water Corporation offer BYDA services. Always confirm utility locations and adhere to the Territory's specific safety protocols and clearance requirements before starting excavation.

Australian Capital Territory

For Australian Capital Territory, consult with asset providers such as Icon Water and EvoEnergy. Follow local guidelines and ensure all clearance requirements are met to avoid any disruptions to underground infrastructure.

To find out more, contact HIA's Building Services team.

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