Water storage for family touring: how much you actually need and where to put it

Our van carries 160 litres across two tanks and I still ran out at a free camp near Menindee two winters ago, four days into what I'd planned as a five-day stay. Two kids, a dog, dishes twice a day and one very long, very hot argument about whether the shower counted as "essential." It did not run dry because our tanks were too small. It ran dry because I hadn't actually worked out what our family uses per day, I'd just guessed.

That's the gap I want to close here. Water storage for caravan touring isn't really about tank size, it's about matching capacity to actual daily use, then storing that water somewhere that doesn't wreck your tow ball weight or your suspension. Get the sums right and free camping stops being a gamble.

Working out real daily water use, not brochure numbers

Forget the "average person uses X litres a day" stat you'll see quoted everywhere, because it's usually based on a household with a washing machine and a full bathroom, not four people rationing out of jerry cans. In practice, once you're being careful, a family of four doing basic hygiene, cooking, dishes and drinking water gets through somewhere between 15 and 25 litres per person per day. That's a wide range, and where you land depends on shower habits more than anything else. We track ours loosely with a permanent marker on the tank gauge and a simple rule: showers are navy-style (wet, off, soap, on, rinse) unless we're on town water at a park. Dishes get done in a tub, not under a running tap. With those habits, our family of four plus a kelpie sits closer to 60-70 litres a day including a modest top-up for the dog's water bowl and the billy.

Do that maths before you buy anything. If you're planning genuine off-grid stretches of four to five days between fills, at 65-70 litres a day you need 260-350 litres of usable capacity, and "usable" is the key word, because you should never plan to run a tank fully dry.

Fresh, grey and the tank sizes that actually matter

Most off-road vans on the market carry somewhere between 120 and 200 litres of fresh water split across one or two tanks, plus a smaller tank for the hot water service, typically 20-28 litres. A handful of serious touring vans go further, up to 300 litres plus, but that's genuinely uncommon and it comes with a weight cost I'll get to. Grey water is the one families forget. If you're free camping away from a dump point, every litre of fresh water you use eventually has to go somewhere, either into a portable grey water tank, a bucket system, or straight onto the ground where it's permitted (check the local rules; a lot of national park and reserve camping specifically bans grey water disposal on the ground). We carry a 40-litre collapsible grey tank under the annexe for exactly this reason. It's not glamorous gear but it's the difference between a legal camp and a fine, or worse, being the family that gets talked about on the community Facebook page.

Where the weight actually goes, and why it matters more than you think

Here's the number that changes people's plans: water weighs one kilogram per litre. A single 200-litre tank, full, is 200kg sitting somewhere on your chassis. Fill both tanks on a van with 160 litres total and you've added 160kg before you've loaded a single bag, book or the dog's bed. That matters because most off-road vans are already tight on payload once you've added solar, batteries, an awning, camp chairs and the kids' scooters. I've written before about the gap between loaded weight and tare weight, and water is usually the single heaviest variable item you control. If your van's ATM leaves you with, say, 350kg of payload after the manufacturer's base tare, filling two 100-litre tanks eats more than half of that before the fridge, the pantry or the kids' stuff goes in. Tank position matters too. Tanks mounted low and central, ideally over or just ahead of the axle group, keep your centre of gravity down and your tow ball weight predictable as they empty. Tanks slung right at the back, behind the axles, will drag your tow ball weight down as they drain, which can tip a van from nose-heavy to tail-happy over a few days of use. If you're shopping for a van, ask where the tanks sit before you ask about the layout of the kitchen.

Filling strategically instead of filling everywhere

The instinct is to top up every tank every chance you get. I'd argue that's often the wrong call for family touring, and here's my mildly unpopular take on it: if you're moving through van parks every second or third night anyway, running your tanks at half capacity most of the time and topping up at each stop carries less weight, uses less fuel, and puts less strain on your suspension and tyres than lugging around 300kg of water you don't need yet. Save the full-tank fill for the day or two before you head somewhere genuinely remote, like a stretch of the Oodnadatta Track or before a run out toward Wilpena Pound where the next tap might be a while off. The rest of the time, half-full tanks and a habit of filling at every legitimate opportunity, town taps, caravan parks, servo taps where permitted, keeps the rig lighter and the tow ball weight more consistent day to day.

Camp kitchen habits that actually save litres

The camp kitchen is where families burn through water fastest and it's also where the easiest savings sit. A few things that actually moved the needle for us, not gimmicks, just habit changes: Washing dishes in a plastic tub rather than under a running tap saves a genuinely large amount, easily 10-15 litres a day for a family of four. Wipe plates with a paper towel before washing to cut grease load, which means less water and less detergent needed to get things clean. Pre-mixing the kids' cordial or milk in a labelled bottle at the last town stop avoids opening the tank tap for small top-ups all day. And a foot pump or gravity tap on your kitchen setup, rather than a 12V pump running constantly, teaches kids fast that water doesn't come from an infinite source, because now they can feel themselves pumping it. None of this replaces having enough tank capacity. It just means the capacity you've got stretches further, which matters most on the days your plans change and a two-night stop turns into four because everyone's having a good time.

Backup water and the gear worth carrying

We carry two 20-litre collapsible jerry cans as backup, stored flat under the bed base when empty and strapped upright in the tunnel boot when full. They're not there for daily use, they're there for the day the tank pump fails, a fitting cracks on a rough track, or we simply misjudge a stretch between towns. A basic water filter or purification setup is worth having too, even if you're mostly filling from taps. Bore water and tank water at remote stations and some free camps isn't always drinking quality, and a simple inline filter or a set of purification tablets weighs nothing and costs less than one night in a caravan park. If you're heading anywhere genuinely remote, the sort of country covered on the Red Centre Way or further out, it's worth checking current water availability with the relevant park or station before you commit, because bore quality and tap access both change with the season.

The honest version of this whole topic is that water storage is a trade-off you make every single day of a trip, not a spec you set once and forget. Work out what your family actually uses, not what a brochure says you should use, size your tanks to that with a buffer, and think about where the weight sits before you think about how much of it there is. Get that right and the only water drama left is negotiating whose turn it is on dish duty.