Water and Waste Management in Your Motorhome
Understanding water and waste systems is fundamental to comfortable motorhome living. These systems require regular attention and proper management to function well, prevent odours, and ensure you're being environmentally responsible. While the topic might not be glamorous, mastering these essentials makes the difference between enjoyable travel and frustrating problems.
Motorhomes typically have three water systems: fresh water for drinking and washing, grey water from sinks and showers, and black water from the toilet. Each system has specific requirements for filling, usage, and disposal. This guide walks you through everything you need to know.
Fresh Water System
Your fresh water tank is the heart of comfortable motorhome living, providing water for drinking, cooking, showering, and cleaning. Tank sizes vary from 50 litres in compact campervans to 300+ litres in large motorhomes, with most falling in the 100-200 litre range.
Filling Your Tank
Fill only from potable water sources—not all taps provide drinking water. Most caravan parks have dedicated drinking water taps marked accordingly. Use a dedicated food-grade hose for filling; never use garden hoses or unknown hoses, which may contain contaminants or have been used for other purposes.
Before filling at a new location, run water through the tap for 30 seconds to flush any standing water. This is particularly important at rest areas or infrequently used taps. If you're uncertain about water quality, err on the side of caution—gastrointestinal illness far from medical care is no joke.
Water Conservation
Conserving water extends your independence between refills. Navy showers (wetting down, turning off water while soaping, then rinsing) use a fraction of normal shower water. Catching rinse water in a basin for later use (watering plants, flushing) stretches supplies further. Fix dripping taps immediately—even small drips waste surprising amounts over time.
A typical household shower uses 7-9 litres per minute. Navy showers can reduce this to 10-15 litres total. When free camping, plan for 10-15 litres per person per day minimum, including drinking, cooking, and basic hygiene.
Water System Maintenance
Sanitise your fresh water system every few months, or immediately if you notice any off taste or smell. The process involves draining the tank completely, adding a sanitising solution (food-grade chlorine or specialised products), filling the tank, running sanitised water through all taps, letting it sit for several hours, then flushing thoroughly until no chlorine taste remains.
If your motorhome will sit unused for more than two weeks, drain the fresh water tank to prevent stagnation. Bacteria thrive in warm, stagnant water—Australian temperatures accelerate this process dramatically.
Grey Water Management
Grey water is wastewater from sinks and showers, collected in a separate holding tank. While less offensive than black water, grey water still requires proper management and disposal.
Understanding Your Grey Water
Grey water contains soap residues, food particles, grease, and bacteria. Left sitting in warm conditions, it develops unpleasant odours within days. Regular emptying prevents smell problems and keeps your system functioning correctly.
Grey water tank capacity varies widely between motorhomes. Smaller campervans might hold only 40 litres, while larger motorhomes may have 100+ litre tanks. Know your capacity and monitor levels using your tank gauge or by tracking usage.
Responsible Disposal
Always dispose of grey water at designated dump points. While some jurisdictions allow grey water disposal on the ground in certain situations, the safest and most environmentally responsible approach is using proper dump facilities. Most caravan parks have dump points; many towns also provide public facilities for travellers.
Never dump grey water into storm drains, waterways, or directly onto vegetation near campsites. Even biodegradable soaps can harm aquatic ecosystems, and accumulated grey water damages soil and plants over time.
Grey Water Best Practices
- Empty grey water tanks every 2-3 days in warm weather
- Use RV-friendly, biodegradable cleaning products
- Minimise food scraps entering the system—use sink strainers
- Only dispose at designated dump points
- Flush the tank periodically to prevent buildup
Black Water (Toilet Waste) System
Black water management is often the most daunting aspect for new motorhomers, but with proper understanding and routine, it's straightforward and odour-free.
Types of Motorhome Toilets
Cassette toilets are most common in Australian motorhomes. The waste collects in a removable cassette (typically 15-20 litres) accessed from an external compartment. When full, you remove the cassette and empty it at a dump point. This system is simple, reliable, and allows easy disposal without moving the motorhome.
Some larger motorhomes have fixed black water tanks with external dump valves, similar to American RVs. These hold more capacity but require positioning the vehicle near dump facilities for emptying.
Composting toilets are gaining popularity among eco-conscious travellers. They separate liquids and solids, using biological processes to break down waste. While they require different management, many users find them cleaner and more convenient once accustomed to the system.
Using Your Toilet Correctly
Only human waste and toilet paper should enter the toilet—nothing else. Use single-ply, quick-dissolving toilet paper or RV-specific paper. Avoid "flushable" wipes, sanitary products, or anything that won't break down quickly.
Add appropriate holding tank chemicals after each empty. These break down waste, control odours, and maintain the system. Choose environmentally friendly formulations where possible, and follow dosage instructions—more isn't better and can actually impair function.
Emptying Procedures
Wearing gloves is recommended when handling cassettes or dump valves. Modern cassette toilets are designed for clean, splash-free emptying, but accidents happen. Rinse the cassette thoroughly after emptying and add fresh water and treatment chemicals before returning it to the motorhome.
Clean the cassette or tank regularly with appropriate cleaners to prevent buildup and maintain seals. Inspect seals annually and replace if showing wear—compromised seals lead to leaks and odours.
Never empty black water anywhere except designated dump points. Illegal dumping is an environmental offence with significant fines, damages ecosystems, and gives all motorhomers a bad reputation. Dump points are widely available at caravan parks, rest areas, and service stations.
Water Pumps and Plumbing
Your 12V water pump pressurises the system, delivering water to taps on demand. Most pumps are self-priming and automatically activate when taps open, shutting off when flow stops.
Pump Maintenance
Listen for changes in pump operation. Pumps running constantly, cycling on and off rapidly, or making unusual noises may indicate problems. Common issues include air in the system (self-resolving after running taps), filter blockages (clean regularly), or failing pressure switches.
Many motorhomes have inline water filters before taps. Replace these according to manufacturer recommendations or when flow rate decreases noticeably. Filters improve taste and remove sediment but aren't always rated for pathogen removal—understand what your filter does and doesn't do.
Winterising Considerations
While most of Australia doesn't require full winterisation, those travelling to alpine areas or storing motorhomes in cold regions should protect against freezing. Water expands when frozen, potentially cracking pipes, pumps, and tanks. Drain systems completely or use non-toxic RV antifreeze when sustained sub-zero temperatures are expected.
Hot Water Systems
Motorhome water heaters typically operate on gas, 240V electricity, or both. Smaller units heat 10-15 litres on demand; larger systems store 20-30 litres of preheated water. Understanding your system helps manage energy and ensures hot water when needed.
Gas heating is efficient and works off-grid but requires adequate gas supply and proper ventilation. Electric heating is convenient when connected to mains power but slow and battery-intensive when running from house batteries. Many travellers use gas while free camping and switch to electric at powered sites.
Drain hot water systems if the motorhome will sit unused for extended periods. Stagnant hot water tanks can develop bacterial contamination, including Legionella in severe cases. Running the system hot (above 60°C) periodically helps prevent bacterial growth during regular use.
Building Good Habits
Successful water and waste management comes down to routine. Check tank levels daily, empty waste tanks before they're completely full (easier and cleaner), and address any issues immediately before they become problems. With consistent attention, these systems function reliably and invisibly, letting you focus on enjoying your travels.
Remember that responsible waste management protects the environment, maintains access to camping areas, and ensures the motorhome lifestyle remains viable for future travellers. Your practices matter—be a good ambassador for the motorhome community.