Rainwater Tanks

What is a Rainwater Tank?

A rainwater tank is a covered container (or group of containers) used to collect and store rainwater from your roof. It’s considered a Class 10 structure under building regulations, and includes the tank stand or structure that supports it.

Do I Need Council Approval?

You don’t need building approval if your tank meets all of the following:

  • Less than 10m² in area or under 3.6m in diameter
  • Less than 2.4m high from natural ground level
  • Less than 5.0m in length
  • Structurally sound for its water volume and pressure

Exceptions and extras:

If your tank exceeds any of the limits above, you’ll need building approval. See details below on setbacks and location requirements.

Tank Location & Boundary Setbacks

Choose a location that:

  • Suits your needs
  • Doesn’t negatively impact your neighbours (think overflow, blocked light, aesthetics)

Check for:

  • Proper boundary and easement setbacks
  • Adequate distance from onsite sewerage systems

For properties over 450m² (refer to QDC MP1.2):

  • Front boundary: Minimum 6.0m from the road (some exceptions apply)
  • Side and rear boundaries:
    • Can be built to boundary if tank is under 3.5m diameter, 2.4m height, and 9m total boundary length
    • Must be 1.5m away from habitable room windows
    • If tank is longer than 5m, setback relaxation may be needed

Check with Council for specific measurements or if your lot is under 450m².

Plumbing Fixtures and Connections

If your tank is connected to toilets, washing machines, or internal plumbing and also linked to the town water supply:

  • A licensed plumber must submit a Form 4 (Notifiable Work) to the QBCC
  • Your system must include:
    • An automatic switching device, OR
    • A backflow prevention device

For new builds, rainwater tanks are assessed during your plumbing and building application process.

Tank Overflow

It’s your responsibility to ensure overflow from your tank:

  • Doesn’t flood neighbouring properties
  • Is safely discharged to:
    • A kerb and channel
    • An inter-allotment drainage system, or
    • A properly designed soakage pit

Ongoing Maintenance

Keep your tank clean and safe with regular checks. This includes:

  • Mosquito screens
  • Gutter guards
  • First flush diverters
  • Filters and backflow devices

Proper maintenance protects your household, neighbours and the environment.

Overland Stormwater Flow

If you're building structures, landscaping, or adding tanks:

  • You must not block or redirect natural stormwater flow to neighbouring properties
  • Disputes between neighbours can be taken to QCAT
  • Council may investigate if stormwater is caused by faulty roof or tank drainage

More Information

  • Queensland Development Code:
    • MP1.2 - Design & Siting
    • MP4.1 - Sustainable Buildings
    • MP4.2 - Rainwater Tanks and Supplementary Water Supply
  • Queensland Health - health.qld.gov.au for safe tank use and water quality tips
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