The Complete Caravanners’ Guide To Carrying Water

Water is your most critical resource on the big lap. Unlike fuel, you can’t always guarantee finding a tap where you need one. Whether you’re planning to stay at caravan parks every night or spend weeks free camping in remote areas, understanding your water carrying options will determine how comfortable and flexible your travels can be.

Most caravans come with basic water tanks, but that’s rarely enough for extended travel. The difference between carrying 100 litres and 300 litres isn’t just comfort – it’s the difference between being tied to caravan parks every few days and having the freedom to explore remote areas for weeks.

Your water carrying strategy needs to match your travel style, caravan setup, and where you plan to go. Here’s everything you need to know about the options available.

Built-in Water Systems

Every caravan comes with some form of built-in water system, but there’s massive variation in capacity and design. Understanding what you have (and its limitations) is the starting point for planning your water carrying strategy.

Standard Fresh Water Tanks

Most caravans include a fresh water tank ranging from 80-200 litres. Entry-level caravans often have 80-120 litre tanks, while larger family vans might include 150-200 litres. These tanks are typically mounted under the floor or in a front boot compartment.

The tank location matters more than you might think. Under-floor tanks are protected but can be awkward to access for cleaning. Front-mounted tanks in the A-frame area are easier to service but take up valuable storage space.

Grey Water Systems

Grey water tanks collect waste water from sinks and showers. Most caravans include 60-120 litre grey water tanks, though some budget models skip this entirely and drain straight to the ground (illegal in many areas).

Your grey water capacity often limits your fresh water usage more than the fresh tank itself. There’s no point carrying 200 litres of fresh water if your grey tank fills up after using 80 litres.

Hot Water Systems

Hot water systems typically hold 20-25 litres, which doesn’t add much to your total capacity but does affect your water management. Electric-only systems limit you to powered sites, while gas or diesel systems give you hot water anywhere.

Additional Water Tanks

For serious big lappers, additional water tanks are usually essential. You can add tanks in various locations, each with different advantages and installation requirements.

Underslung Tanks

Underslung tanks mount beneath your caravan, typically between the wheels or behind the rear axle. These are the most popular upgrade because they don’t take up interior storage space.

Quality underslung tanks like the Roadtech Marine 100L underslung tank ($450) mount securely and include proper drainage and inspection ports. Cheaper options often lack adequate mounting systems or proper baffles to prevent water surge.

Rear-mounted tanks are easier to install but affect weight distribution more than mid-mounted options. You’ll need to consider your caravan’s weight distribution and ensure you don’t exceed axle weight limits.

A-Frame Tanks

A-frame tanks mount in the front triangle of your caravan, either in existing storage compartments or purpose-built tank boxes. These improve weight distribution by adding weight over the tow ball.

The RV Water Tank Solutions A-Frame 120L tank ($520) includes mounting brackets designed for most Australian caravan A-frames. Installation typically requires some fabrication work unless your caravan was pre-fitted for additional tanks.

Internal Auxiliary Tanks

Internal tanks use interior storage space, usually in wardrobes, under beds, or in dedicated compartments. While this reduces storage space, internal tanks are easier to access for cleaning and don’t affect ground clearance.

Flexible bladder tanks like the Flexitank 200L water bladder ($280) can fit into odd-shaped spaces that rigid tanks can’t use. However, they’re harder to clean thoroughly and may need replacement every few years.

Plumbing Integration

Additional tanks can be plumbed into your existing system with automatic switching valves, or kept separate with manual transfer pumps. Integrated systems are more convenient but more complex to install and troubleshoot.

Manual systems using 12V transfer pumps give you more control over which tanks you use when, and make it easier to manage different water sources (tank water for washing, good water for drinking).

Portable Water Containers

Portable containers provide flexibility that fixed tanks can’t match. You can leave them behind when you don’t need them, carry them to water sources your caravan can’t reach, and use them for specific purposes.

Jerry Cans

Water jerry cans are the most versatile portable option. Quality cans like the Scepter Military Water Can 20L ($85) are virtually indestructible and stack securely during travel.

Standard jerry cans hold 20 litres, which is manageable for most people to lift and pour. Some brands offer 10L and 25L options, but 20L hits the sweet spot between capacity and usability.

The key with jerry cans is having proper mounting systems. Loose jerry cans become dangerous missiles in an accident. Quality mounting brackets or storage systems keep cans secure and accessible.

Large Portable Tanks

Wheeled water containers like the Camec 100L wheelie water tank ($180) bridge the gap between jerry cans and fixed tanks. They’re too large to carry when full but can be positioned near your caravan and connected with a hose.

These work well for extended stays in one location, particularly for free camping where you might get a water delivery or need to collect water from a distant source.

Collapsible Containers

Collapsible water containers store flat when empty but can hold 10-40 litres when needed. They’re useful for specific situations but don’t replace your main water carrying capacity.

Quality matters enormously with collapsible containers. Cheap options often leak at the seams or develop taste issues. The Platypus Platy Water Tank 10L ($45) is designed for backcountry use and holds up better than camping store alternatives.

Water Caddies and Jugs

Small water containers (5-10 litres) with taps are handy for outdoor cooking, washing hands, or keeping drinking water accessible. They don’t add significant capacity but improve convenience around camp.

Water Quality and Filtration

Carrying more water is pointless if it’s not safe to use. Water quality varies dramatically across Australia, and stored water can develop problems even if it started clean.

Source Water Quality

Town water meets drinking standards, but taste and mineral content vary wildly. Some bore water is excellent for drinking, while other sources are only suitable for washing. Always ask locally about water quality before filling up.

Tank water (rainwater) is generally safe if the tanks and gutters are clean, but may lack minerals and can pick up debris or bird droppings. Station water ranges from excellent artesian sources to brackish bores only suitable for stock.

Storage Considerations

Water stored in tanks for weeks can develop taste issues or bacterial growth, even if it started perfectly clean. Dark tanks reduce algae growth, but temperature and air exposure matter more.

Regular tank cleaning is essential for long-term travellers. Every few months, you should empty, rinse, and sanitise your tanks. Some Big Lappers do this quarterly, others whenever they notice taste changes.

Filtration Systems

Whole-of-system filters treat all water entering your caravan, while point-of-use filters only treat water for specific purposes (usually drinking and cooking). Each approach has advantages depending on your water sources and usage patterns.

The Puretec Traveller MAX system ($680) handles most Australian water issues including bacteria, chlorine taste, and sediment. It mounts permanently in your caravan and treats water as you use it.

Storage and Weight Considerations

Water is heavy – every 100 litres adds 100kg to your rig. This weight affects everything from tyre pressures to braking distances, and you need to consider where that weight goes.

Weight Distribution

Water placement significantly affects your caravan’s handling. Water over the axles has minimal impact on ball weight, while water behind the axles reduces ball weight and water ahead of the axles increases it.

Most caravans benefit from some additional weight forward of the axles, so A-frame tanks often improve handling rather than hurting it. However, you need to monitor your total ball weight to ensure it stays within your vehicle’s limits.

Payload Calculations

Every litre of water carrying capacity reduces your payload for other gear. A caravan with 1,500kg total payload that carries an extra 200L of water (200kg) has just 1,300kg left for everything else.

Calculate your typical water load (tanks 75% full is realistic for most travel) and subtract this from your available payload before loading other gear.

Accessibility and Convenience

The most convenient water storage is internal tanks with level gauges and pump systems. However, internal storage takes space from other gear and may require more complex plumbing.

External tanks and containers require manual handling but don’t consume interior space. The trade-off depends on your physical capabilities and travel style.

Our Recommendations by Travel Style

Your ideal water carrying setup depends entirely on how you plan to travel. Here’s what works for different Big Lap styles.

Caravan Park Hoppers (2-3 nights maximum between parks)

Standard caravan tanks are usually adequate. Focus on a quality 20L jerry can for backup and a good filtration system to improve water taste. Total water carrying: 120-180L.

The Scepter 20L jerry can ($85) plus tank-mount bracket covers your backup needs. Add a Puretec Traveller inline filter ($280) for better tasting water everywhere.

Mixed Travellers (3-7 days between services)

Add 100-150L of additional tank capacity plus 40-60L in portable containers. This gives you enough water for a week of comfortable living without rationing. Total water carrying: 250-350L.

Best setup: Roadtech 120L underslung tank ($480) plus two 20L jerry cans. This adds serious capacity without compromising storage space or ground clearance too much.

Serious Free Campers (1-3 weeks between services)

Maximum water carrying is essential. Plan for 300-500L total capacity using multiple tank locations. You’ll need careful weight management and robust filtration systems. Total water carrying: 400-600L.

Recommended setup: Standard tank plus A-frame tank (120L), underslung tank (150L), and multiple jerry cans (60-80L). Add a comprehensive filtration system and water quality testing kit.

Remote Area Specialists (3+ weeks between services)

Plan for water deliveries, solar stills, or other water acquisition methods. Carrying enough water for a month is impractical for most rigs. Focus on efficient usage and multiple acquisition methods rather than just more storage.

Essential gear includes water quality test strips, purification tablets, and emergency water location knowledge. The Katadyn Pocket water filter ($450) can purify questionable water sources when necessary.