Rainwater Tanks – Approvals, Installation and Maintenance Guide
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:
- Extra conditions may apply under the Queensland Development Code MP4.2
- If your property is in a bushfire hazard area with no town water, different rules may apply – check Council’s Planning Scheme Mapping and the Bushfire Hazard Overlay Code
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