Short answer: Australia does not have one nationwide rule requiring every caravan to carry a fixed grey-water tank. However, many councils, parks, showgrounds and private camps require all grey water to be contained and disposed of at an approved point. A fixed tank is the most convenient way to meet those rules; a sealed portable container may be accepted in some places.
What counts as grey water?
Grey water is wastewater from sinks, showers and washing—not toilet waste. It can contain food, grease, detergent, dirt and microorganisms. “Only clean shower water” can still create odour, muddy sites, attract animals or enter waterways.
There is no single campsite rule
| Place or authority | Example approach | What you should do |
|---|---|---|
| South Australian national parks | Tanks are not universally mandatory, but strongly recommended; limited disposal guidance applies | Read the current park page and any booking conditions |
| Some council or holiday parks | All grey water must be contained and taken to a dump point | Arrive with working fixed or accepted portable capacity |
| Serviced caravan sites | A sullage point may be provided | Use the approved connection and prevent leaks |
| Self-contained RV areas | Local definition can require integrated containment | Check the exact council rule before travel |
The controlling authority’s rule applies at that location. A practice allowed at one campground can be prohibited at the next. When the rule is unclear, contain the water until you can ask.
Fixed tank or portable container?
| Option | Advantages | Trade-offs |
|---|---|---|
| Fixed underslung tank | Convenient, secure and supports self-contained travel | Adds permanent weight; needs plumbing, drainage and protection |
| Portable sealed container | Lower-cost retrofit and easy to empty when light | Limited capacity, storage, lifting and acceptance vary by site |
| Direct sullage hose | Simple on a serviced site | Not containment and unusable where no approved drain exists |
How much capacity?
Start with measured daily grey-water production. Kitchen habits and showers can fill a tank faster than expected. Capacity should cover the longest period between approved disposal opportunities, while remaining inside payload and axle limits. Every litre retained adds about one kilogram while towing.
A tank does not have to match fresh-water capacity in every touring pattern because some water is drunk or used outside the onboard system, but undersizing it can exclude camps. The water-weight calculator helps show the payload effect.
Installation details that matter
- A level indicator you can trust and an accessible drain valve.
- Venting and traps that control odour without causing slow drainage.
- Protection from road debris and adequate ground clearance.
- Pipe falls that drain properly and do not retain stagnant water.
- A hose and fittings dedicated to wastewater, stored away from drinking-water equipment.
Plumbing modifications should follow the product instructions and applicable requirements. Reweigh the caravan after adding a large tank and its supporting structure.
Responsible disposal
Use the campground’s sullage connection or an approved dump point as directed. Never empty into stormwater, waterways or another campsite. Do not assume “biodegradable” detergent makes ground discharge acceptable. Food scraps and grease should be wiped into rubbish before washing to reduce odour and tank build-up.
Who benefits most?
- Travellers using low-cost or self-contained RV areas.
- Remote campers who stay several nights without a sullage connection.
- Families using an onboard shower and kitchen.
- Anyone who wants more campsite choice with less last-minute uncertainty.
If you almost always use serviced caravan parks, a fixed tank may be less important—but confirm each booking. For the complete tank system, read fresh, drinking and grey-water tanks explained.
An Australian touring scenario
A couple moving between fully serviced caravan parks may connect a sullage hose at nearly every stop and rarely retain grey water. The same van may be refused at a council RV area that requires self-containment. A family using an onboard shower can create tens of litres quickly and may need a fixed tank sized for an overnight stay. A small camper with only a hand basin might comply at some sites using a sealed portable container, but must confirm acceptance before arrival.
Limits of brochure comparisons
Grey-water rules can appear in legislation, council permits, park conditions, booking pages or signs at the site. “Not mandatory in this state’s national parks” does not mean every park or council area allows ground discharge. Likewise, a self-contained sticker or club scheme does not override the controlling authority. Save the current rule or booking condition when access depends on containment.
What to verify before buying or changing the system
- Definition of self-contained used by each intended campsite
- Whether a portable container is accepted or an integrated tank is required
- Daily sink and shower output for the travelling party
- Capacity needed before the next approved disposal point
- Full tank weight, tank position and axle/payload margin
- Vent, drain, level indication and freeze or stone protection
- Dedicated wastewater hose and hygienic storage
- Cleaning access and a plan for odour or blockage
Ongoing operation and maintenance
Wipe food and grease from dishes before washing, use strainers and empty only at an approved point. Flush the tank and hoses according to the system maker, then allow them to drain. Keep wastewater equipment physically separate from drinking-water hoses and fittings. Inspect mounts, valves and guards after rough roads. If a tank level indicator becomes unreliable, repair it rather than waiting for overflow as the warning.
A fair way to compare quotes
Give every supplier the same written brief: travelling party, normal destinations, longest unserviced stay, existing equipment, available installation space and remaining payload. Ask for the exact model numbers and manuals rather than accepting a category description. The quote should separate hardware, installation, commissioning, certification where applicable and removal or safe decommissioning of old equipment. It should also state exclusions, warranty responsibility and the added installed mass.
Compare the proposals against the same ordinary worst case. For electrical systems, that may be consecutive cloudy days and the largest simultaneous load. For water or waste systems, it may be the longest stay before lawful refill or disposal. For fuel-burning equipment, include cold starts, ventilation, fuel availability and servicing. A design that works only under ideal sun, perfect coverage or unlimited site facilities is not a touring plan.
Score each option for five things: safety and compliance, fit with your actual travel, payload, daily effort and recoverability after a fault. Purchase price belongs in the comparison, but so do new chargers, tanks, vents, cabling, plumbing, certification and future consumables. Give extra weight to factors that can strand you or close access to a campsite.
Plan for a fault, not just normal operation
Ask what happens when the chosen system fails on a Sunday in a regional town. Identify the safe isolation method, what other equipment is affected, whether the caravan remains usable and which parts are realistically stocked in Australia. A highly integrated appliance can save space but may remove several functions at once. Separate systems can provide redundancy but add weight, connections and maintenance. There is no universal winner; record the consequence that matters to your trip.
Carry only the spares and tools the manufacturer permits an owner to use. Do not bypass fuses, pressure devices, ventilation, battery management or combustion safety controls to keep travelling. If a fault involves gas, 230V electricity, overheating, fumes, damaged lithium batteries or leaking waste, isolate the equipment if safe, move people away from the hazard and obtain qualified assistance.
Recheck the decision when your travel changes
A setup chosen for powered coastal parks may not suit a remote inland season. Revisit capacity, fuel, payload and service access after adding appliances, changing tow vehicles, travelling with more people or planning longer stays. Reweigh after material modifications and keep the measured axle and total masses with the system records. This prevents several individually reasonable upgrades from quietly consuming the safety margin.
When keeping the current system is sensible
An upgrade is not automatically progress. If the present equipment is safe, supported and reliably covers your ordinary trips, maintenance or a small complementary item may solve the real problem with less weight and complexity. Replace equipment when measured performance, route requirements, safety, serviceability or a clearly defined new use justifies the change—not simply because a newer technology is popular.
Commissioning and trip records
Before departure, ask the installer to demonstrate normal operation, isolation, alarms, fault messages and safe shutdown. Keep the manual, model and serial number, invoice, commissioning information and a simple diagram with the caravan records. On the first trip, note energy or fuel use, temperatures, refill or disposal intervals and any nuisance alarms. Those observations turn the next adjustment into evidence-based maintenance rather than guesswork.
Your practical next step
Measure grey water for two ordinary days by collecting sink and shower discharge in known containers at home or on a serviced site. Add a margin for the longest planned stay, then check whether the full weight fits the caravan’s limits. Verify that capacity against three actual destination rules before choosing fixed or portable containment.
Sources and further reading
- South Australia National Parks camping essentials
- Noosa Holiday Parks grey-water rules
- Australian Caravan Club ACCESS self-containment guidance
Information checked 24 August 2026. Product specifications and campsite rules can change; confirm the current manual and local requirements before relying on them.
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