The Complete Caravanners’ Guide To Carrying Water

Water is life on the road, but how much do you really need, and what’s the best way to carry it? Most new caravanners dramatically underestimate their water needs and storage requirements, leading to cramped travels and constant anxiety about running dry.

Your water system is actually three interconnected decisions: how much water to carry, where to store it, and how to access it reliably. Get any one wrong and your entire setup becomes a compromise. The good news? Once you understand the options, choosing the right system for your travels becomes straightforward.

How Much Water Do You Actually Need?

The standard calculation is 100 litres per person for a week of free camping, but this number means nothing without context. Your actual water consumption depends on climate, cooking habits, shower frequency, and whether you’re washing dishes or using disposables.

A couple using their caravan shower daily, cooking fresh meals, and travelling through warm weather will easily consume 120-150 litres per week. Add pets or teenagers and you’re looking at 200+ litres. Conversely, minimalists using camp showers and eating mostly one-pot meals can survive comfortably on 80-100 litres weekly.

Tank sizing creates a classic engineering trade-off: larger tanks mean more self-sufficiency but add weight and reduce payload. The sweet spot for most Big Lappers is 150-200 litres total capacity, split between multiple tanks for weight distribution and redundancy.

Water Consumption by Activity

• Drinking and cooking: 8-12 litres per person daily
• Caravan shower: 15-25 litres per person (varies by shower head and duration)
• Washing dishes: 5-10 litres daily for two people
• Basic washing/teeth: 2-3 litres per person daily
• Pets: 2-5 litres daily depending on size and temperature

Fresh Water Tank Types and Placement

Your water storage choice fundamentally shapes your caravan’s centre of gravity, payload capacity, and plumbing complexity. The three main approaches each solve different problems.

Built-in Poly Tanks

Integrated poly tanks mounted under the caravan chassis are the most common solution. They’re protected from damage, don’t take up interior space, and can be shaped to fit available space efficiently.

The downside is weight distribution. A 200-litre tank adds 200kg to your caravan’s mass, and if it’s mounted behind the axle, it reduces ball weight and makes the van more prone to sway. Quality tanks from manufacturers like Projecta ~$280-450 or Camec ~$320-520 include proper mounting systems and UV protection.

Flexible Bladder Tanks

Bladder systems like those from Water Bladder Australia ~$850-1,200 conform to irregular spaces and can be placed in multiple locations. They’re popular for retrofitting caravans that lack proper tank mounting points.

The flexibility comes at a cost: bladders are more expensive per litre than rigid tanks, require careful installation to prevent chafing, and typically last 5-8 years before requiring replacement. They’re excellent for custom installations but overkill if your caravan can accommodate standard tanks.

Internal Tank Systems

Some caravanners mount tanks inside storage compartments or under beds. This approach maximises protection and can improve weight distribution, but sacrifices valuable storage space.

Internal mounting works best with modular systems where you can use multiple smaller tanks. Brands like RV Water Tank Store ~$180-320 offer rectangular tanks designed specifically for tight spaces.

Water Pressure Systems Explained

Your water pressure system determines whether you get city-like water flow or a disappointing trickle. The choice affects everything from shower comfort to how quickly you can fill the kettle.

12V Demand Pumps

Demand pumps activate when they detect pressure drop, running only when water flows. They’re the most popular choice because they’re simple, reliable, and provide consistent pressure regardless of tank level.

Quality demand pumps like the Shurflo deliver 11-15 litres per minute at 40+ PSI, enough for comfortable showers and quick tank filling. Cheaper units often struggle with pressure consistency and tend to cycle on/off annoyingly during use.

Accumulator Tank Systems

Accumulator tanks store pressurised water, reducing pump cycling and providing more consistent flow. They’re particularly valuable if you have multiple water outlets or use appliances that frequently start/stop water flow.

The Shurflo Accumulator Tank ~$185 pairs perfectly with their pump systems and nearly eliminates the on/off cycling that makes cheap pumps sound like angry robots. The trade-off is additional space and complexity.

Gravity Fed Systems

Elevated tanks feeding by gravity alone are simple and silent but provide low pressure that struggles with modern fixtures. They work fine for basic taps but make shower time an exercise in patience.

Gravity systems make sense for ultra-minimalist setups or as backup systems, but most caravanners find the pressure inadequate for comfortable daily use.

Essential Water System Accessories

A basic tank and pump get water flowing, but the accessories determine whether your system is pleasant to use or a constant source of frustration.

Water Level Monitoring

Knowing how much water remains prevents both premature town stops and unexpected dry camps. External sight gauges are cheap and reliable, while electronic monitors like the SeeLevel II System ~$320 provide precise readings from inside the caravan.

Filtration Systems

Tank water tastes like plastic for the first few months, and town water quality varies dramatically across Australia. A quality filter system improves taste and removes sediments that can clog fixtures.

Hot Water Systems

Your hot water system choice affects both daily comfort and water consumption patterns. Instant gas systems provide unlimited hot water but require adequate gas supply. Electric systems are simpler but drain batteries quickly when off-grid.

The Suburban SW6DE ~$1,850 offers both gas and electric heating, giving you options based on your current setup. Storage capacity is modest at 22 litres, but recovery time is quick.

Water Filling and Management

Gravity filling through a standard caravan inlet takes forever with large tanks. Pressure filling systems cut fill times dramatically but require compatible town water connections.

The Fiamma Aqua 8 ~$85 pressure filling system reduces a 30-minute gravity fill to under 10 minutes. Essential if you’re running large tanks and don’t want to spend half your town visits waiting for water.

Keeping Your Water System Healthy

Water systems require more maintenance than most caravanners expect. Tank sanitisation, pump servicing, and filter replacement aren’t optional activities—they’re essential for both system longevity and health.

Tank Sanitisation

Fresh water tanks develop biofilms and bacteria over time, especially when sitting unused or filled from questionable sources. Sanitise tanks monthly using unscented household bleach at a ratio of 1ml per 10 litres of tank capacity.

Fill the tank partially, add the bleach solution, top up with fresh water, and run all taps until you smell chlorine. Let it sit for 4-6 hours, then drain completely and refill with fresh water. Run taps again until the chlorine smell disappears.

Pump Maintenance

Demand pumps are mostly maintenance-free, but the internal pressure switch and seals eventually wear out. Symptoms include short cycling, reduced pressure, or the pump running continuously without water flow.

Most pump issues stem from debris in the system or running the pump dry. Install an inline filter before the pump inlet and never operate the pump without adequate water supply.

Winterisation and Storage

Water expands when frozen, destroying pumps, tanks, and plumbing. If travelling through areas where temperatures drop below zero, either drain the system completely or use non-toxic RV antifreeze.

Complete drainage includes the pump, hot water system, and all low points in the plumbing. Many systems have dedicated drain valves, but some require disconnecting fittings to ensure complete evacuation.

Our Water System Recommendations

Your ideal water system depends on travel style, caravan size, and payload capacity. Here’s how we’d configure systems for different Big Lap approaches.

Best Overall Setup

For most Big Lappers, we recommend a 180-200 litre under-chassis poly tank with a Shurflo 4008 demand pump and basic accumulator. This provides 10-14 days of comfortable free camping for two people while maintaining reasonable weight and complexity.

Budget-Conscious Choice

Single 120-150 litre tank with a basic demand pump covers essential needs without breaking the budget. Skip the accumulator initially—you can add it later if pump cycling becomes annoying.

Maximum Capacity Setup

Dual tank systems with 300+ litre total capacity suit extended remote travel or larger groups. Use separate pumps for redundancy and consider a bypass valve system for maintenance without draining both tanks.