It's one of those questions that sounds simple until you're three days into the bush with an empty tank and the nearest town is 200km away.
Water planning is one of the most underestimated parts of any serious outback trip — and it's also one of the easiest to get wrong. Too little is dangerous. Too much adds unnecessary weight and kills your fuel economy. Getting it right is what separates a great trip from a stressful one.
We've spent a lot of time out there, and we've had this conversation around more campfires than we can count. Here's how we think about it.
Start With the Basics: The 3L Rule
The standard survival guideline in a hot, remote Australian environment is a minimum of 3 litres of drinking water per person, per day. That's the bare minimum if you're resting in the shade and doing nothing strenuous.
In reality, when you factor in cooking, washing up, basic hygiene, and the fact that you're probably not sitting still — plan for 5–8 litres per person per day as a realistic starting point.
| USE | ESTIMATED DAILY AMOUNT |
| Drinking | 3–4L |
| Cooking & food prep | 1–2L |
| Washing up | 1–2L |
| Basic hygiene (face, hands) | 0.5–1L |
| Total per person | 5.5–9L |
Factor in the Conditions
The Australian outback is not a forgiving place in summer. Heat, dust, and physical exertion all increase your water needs significantly. A few factors that will push your consumption higher:
- Temperature. Above 35°C, your body is working hard just to regulate temperature. Budget an extra litre or two per person on hot days.
- Activity level. A day of walking remote tracks or diving gear in and out of the ute demands a lot more hydration than a relaxed day at camp.
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Group composition. Kids and dogs have their own needs. A large dog in summer heat can drink 1–2L a day easily. And if you're travelling with a partner who insists on a long hot shower after a day on the tracks, add another 2L per person per day... some things you just won't win!
- How remote you are. If you're deep in the Kimberley or out at Scott Reef, every litre you carry is the litre you've got.
So How Much Water Storage Do You Need?
Once you know your daily consumption, the maths is straightforward:
Total water = (litres per person per day) × (number of people) × (number of days) + 25% safety buffer
We'd always recommend a 20–25% buffer on top of your calculated total. Trips blow out. You meet people on the track. Something spills. That buffer is your peace of mind.
Example: 2 adults, 7-day trip, moderate activity
- 7L per person per day × 2 people × 7 days = 98L
- Add 25% buffer = ~125L total
That puts you squarely in the territory of our 130L Slim Flexible Water Bladder — which sits neatly in your vehicle footwell without eating into your gear space.
Don't Forget about the weight!
Water weighs 1kg per litre — it adds up fast. 130L is 130kg of payload that'll affect your vehicle's handling, fuel economy, and centre of gravity.
- Place bladders low in the vehicle — footwells, under-seat, or flat in the tray — to keep your centre of gravity down.
- Flexible bladders compress as they empty, so unlike rigid tanks, they don't slosh around as much when partially used.
Our Recommendation
For most two to four person outback trips of five to ten days, 100L to 180L of reliable, portable water storage is the sweet spot. Our Slim bladder range is food-grade PVC, built tough, and designed to fit the awkward spaces that rigid tanks can't.
Questions about sizing for your specific rig? Reach out — we're always happy to help you figure out the right setup before you head out.
→ Browse our full water bladder range here
Stay safe out there, do your preparation, and never underestimate WA's distances.
— The Niche Outdoors Team, Perth WA