The Complete Caravanners’ Guide To Carrying Water

Water is one of your most critical resources on the road. You’ll need it for drinking, cooking, washing dishes, showering, and keeping your caravan systems running. Get your water storage wrong and you’ll find yourself making constant detours to find taps, or worse, running dangerously low in remote areas.

The challenge is balancing capacity with weight. Water weighs one kilogram per litre, so a 200-litre system adds 200kg to your rig. That’s a significant chunk of your towing capacity, but the alternative is being tethered to water sources and severely limiting where you can camp.

This guide breaks down everything you need to know about water storage systems for caravans, from basic fresh water tanks through to grey water management and water-making systems.

Fresh Water Storage Systems

Your fresh water system is the foundation of your water setup. Most caravans come with a basic fresh water tank, but understanding your options helps you make better decisions about upgrades or replacements.

Standard Fresh Water Tanks

Factory-fitted fresh water tanks typically range from 80 litres in compact caravans to 200+ litres in larger family vans. These tanks are usually mounted underneath the van between the chassis rails for optimal weight distribution.

The key considerations for your main tank are capacity, material, and mounting location. Mounting the tank low keeps your centre of gravity down but makes it vulnerable to road debris. Some manufacturers now offer internal tanks mounted inside storage compartments, trading some capacity for better protection.

Auxiliary Water Storage

Many Big Lappers add auxiliary water storage to extend their range. This might be additional tanks mounted elsewhere on the van, or portable containers that can be filled separately and used to top up your main system.

Portable water containers offer flexibility. You can leave them behind when weight is critical, or use them to collect water from sources that are difficult to access with your full rig. The Scepter Military Water Can ~$85 holds 20 litres and is virtually indestructible, while collapsible bladders like the Reliance Aqua-Pak ~$25 store flat when empty.

Tank Materials: Poly vs Steel vs Composite

The material of your water tank affects weight, durability, taste, and cost. Each option has trade-offs that matter depending on your travel style.

Polyethylene (Poly) Tanks

Poly tanks dominate the caravan market for good reasons. They’re lightweight, relatively inexpensive, and won’t rust or corrode. Food-grade polyethylene doesn’t affect water taste, and the material is flexible enough to handle the constant movement and vibration of caravan travel.

The downside is durability. Poly tanks can be punctured by road debris and are vulnerable to UV damage if not properly protected. They also expand and contract with temperature changes, which can stress fittings over time.

Stainless Steel Tanks

Stainless steel tanks are the premium option. They’re virtually indestructible, maintain water temperature better, and have a much longer lifespan. Many European caravan manufacturers use stainless steel as standard.

The trade-offs are weight and cost. A stainless tank might weigh twice as much as an equivalent poly tank and cost three times more. For long-term touring where durability matters more than initial cost, stainless steel makes sense.

Composite and Fibreglass Tanks

Composite tanks try to bridge the gap between poly and steel. They’re stronger than poly but lighter than steel, with good resistance to impact and UV damage. However, they’re more expensive than poly and repairs can be complex.

Water Pressure Systems

How you pressurise your water system affects convenience and water usage. Most caravans use either a 12V pump or a pressure accumulator tank system.

12V Water Pumps

Most caravans come with a basic 12V pump that runs on demand. When you turn on a tap, a pressure switch activates the pump until you turn the tap off. These systems work well but can be noisy and tend to cycle on and off frequently, especially with small leaks or dripping taps.

Accumulator Tank Systems

Accumulator tanks store pressurised water, so your pump doesn’t need to run every time you use a tap. The pump fills the accumulator tank, which then provides pressurised water on demand. This reduces pump cycling, noise, and power consumption.

The Shurflo Accumulator Tank ~$120 is a popular retrofit option that works with most existing pump systems. Installation requires some plumbing knowledge but the improvement in system operation is significant.

Variable Speed Pumps

Premium variable speed pumps adjust their output based on demand. Turn on one tap and get gentle flow, turn on multiple taps and get full pressure. They’re quieter than standard pumps and provide more consistent pressure, but cost significantly more.

Grey Water Management

Grey water is the waste water from your sinks and shower. Managing it properly is essential for responsible camping and staying compliant with dump point regulations.

Grey Water Tank Systems

A proper grey water tank collects waste water for disposal at designated dump points. Most quality caravans include a grey water tank, typically 80-120 litres capacity. The tank should have a secure cap and level indicator.

Grey water tanks add weight and complexity, but they’re essential if you want to camp in national parks or anywhere that doesn’t allow grey water discharge. They also prevent you from creating muddy, smelly areas around your campsite.

Portable Grey Water Solutions

For vans without built-in grey water tanks, portable solutions exist. Collapsible grey water containers can be positioned under your van’s drain outlets, then emptied at appropriate locations.

Grey Water Recycling

Some caravanners install grey water recycling systems that filter and treat grey water for reuse in toilets or external cleaning. These systems are complex and expensive but can significantly extend your water supply in very dry areas.

Water Filtration and Purification

Australian water quality varies dramatically depending on your source. Tank water, bore water, and even town water can contain sediment, chemicals, or biological contaminants that affect taste and health.

Inline Water Filters

Inline filters install in your water line and treat all water entering your caravan. Basic sediment filters remove dirt and particles, while carbon filters also remove chlorine and improve taste. Multi-stage systems combine both.

Point-of-Use Filtration

Point-of-use filters treat water at specific taps, usually just for drinking water. Under-sink systems or countertop units provide high-quality filtered water without treating your entire supply.

The Puretec Hybrid-G13 ~$295 combines sediment and carbon filtration in a compact under-sink unit. It’s designed for caravans and handles the movement and vibration well.

Water Purification

If you’re collecting water from unknown sources, purification goes beyond filtration. UV sterilisers kill bacteria and viruses, while reverse osmosis systems remove almost all contaminants including salt.

The Katadyn PowerSurvivor 40E ~$2,200 is a 12V reverse osmosis system that can even desalinate seawater. It’s expensive but provides complete water independence for remote travel.

Water Level Monitoring

Knowing how much water you have left is crucial for trip planning. Basic level indicators are better than nothing, but digital monitoring systems provide much more useful information.

Analogue Level Indicators

Most caravans come with basic analogue water level gauges. These usually show empty, quarter, half, three-quarter, and full levels. They’re inexpensive and reliable but not very precise.

Digital Monitoring Systems

Digital tank monitoring systems provide precise readings and can track usage over time. Some connect to smartphone apps that log your consumption patterns and predict when you’ll need to refill.

Smartphone-Connected Systems

Premium monitoring systems connect to your smartphone via Bluetooth or Wi-Fi. The Mopeka Tank Check ~$90 uses ultrasonic sensors and provides readings through a smartphone app. You can monitor multiple tanks and set low-level alarms.

How Much Water Do You Actually Need?

Water capacity planning depends on your travel style, group size, and how long you want to stay off-grid. Here’s how to calculate your actual requirements.

Daily Water Usage Estimates

A couple using water conservatively might use 60-80 litres per day, including drinking, cooking, washing dishes, and quick showers. Families with children typically use 100-150 litres daily. If you like long showers and don’t worry about conservation, 200+ litres per day is common.

Break down your usage by category:

• Drinking water: 3-4 litres per person per day
• Cooking and cleaning: 20-30 litres per day
• Showers: 30-50 litres per person per shower
• Toilet (if using fresh water): 5-10 litres per day

Range vs Weight Trade-offs

Every litre of water adds one kilogram to your rig. A couple wanting four days off-grid at 80 litres per day needs 320 litres capacity, adding 320kg to their towing weight.

The alternative is accepting shorter off-grid periods or finding ways to reduce consumption. Low-flow shower heads, foot-pump taps, and careful washing practices can cut usage by 30-50% without major lifestyle changes.

Our Water System Recommendations

After considering capacity, materials, pressure systems, and monitoring, here are our recommendations for different types of Big Lappers.

For Long-term Touring Couples

The sweet spot for most Big Lappers is a 180-200 litre main tank with auxiliary storage options. This provides 4-5 days off-grid with reasonable water conservation, without exceeding most caravans’ payload limits.

Pair this with a variable speed pump and accumulator tank for quiet, efficient operation. Digital monitoring helps you track usage patterns and plan refills.

For Families

Families need more capacity but must watch weight carefully. A 220-250 litre main tank is often the maximum that fits within payload limits. Consider an external grey water tank to extend your campsite options.

Invest in water-saving devices like low-flow shower heads and foot-pump taps. Teaching kids good water habits early makes a huge difference to your range.

For Remote Travel

If you’re heading into truly remote areas, water security becomes critical. Consider a stainless steel tank for durability, and redundancy through multiple smaller tanks rather than one large one.

Water purification becomes essential when collecting from unknown sources. A reverse osmosis system provides complete water independence but requires significant power and produces waste water.