Water storage for touring: tanks, jerries and keeping it drinkable

Water is the one resource where running short changes from inconvenient to dangerous, and it is also the heaviest thing most touring vehicles carry. Those two facts pull in opposite directions and that tension is the whole design problem.

The arithmetic for how much to carry is in water: how much to carry. This is about where to put it.

Weight is the real constraint

A litre of water weighs a kilogram. A hundred litres is a hundred kilograms, and that does not feel like cargo when you are filling a tank from a tap.

It is, though, and it counts against payload the same as anything else. On a well-built touring vehicle already carrying a bull bar, drawers, a fridge and recovery gear, water is frequently the item that pushes the vehicle over its limit. See GVM upgrades explained.

The consequence is that water is worth planning rather than maximising. Carrying 150 litres because the tank holds it, on a trip that needs 80, is 70 kilograms of payload spent on nothing.

Split it

This is the single most important decision and it is not about capacity.

A single large tank is a single point of failure. A cracked tank, a split hose, a failed fitting or a tap knocked open on a track and you lose everything at once, usually without noticing until you check.

Two or three separate containers means one failure costs a fraction of your supply and leaves you with options.

Splitting also lets you place the weight sensibly rather than putting it all in one spot, and it lets you keep one container as designated drinking water that never gets used for washing up.

Where to put it

Low and central is the answer, as close to the centre of the vehicle as you can manage.

Under-body tanks are the best solution for a permanent setup: low, central, out of the way, and using space that is otherwise wasted. They need protection from rock strikes and they are a fixed installation.

In-cabin or canopy tanks work well if they are low and properly restrained.

Jerry cans are flexible, cheap, easy to refill and easy to move between vehicles. Twenty litres is 20 kilograms, so they are at the limit of what is comfortable to lift.

Roof racks are the worst option for water. A hundred kilograms up high on a tall vehicle materially changes how it handles, particularly on side slopes and in emergency avoidance. It is the most common weight-placement mistake in touring.

Behind the rear axle is the second worst. Weight hung a long way back makes a vehicle feel unsettled under braking and on corrugations.

Restraint

Water is dense, and an unrestrained 20-litre jerry travelling at the same speed as the vehicle becomes a projectile in a rollover or a heavy stop.

This is one of the more common serious injuries in touring accidents and it is completely preventable. Proper tie-downs, rated points, and nothing loose in the cargo area.

The same applies to tanks: mounted properly, with brackets designed for the load, not strapped in with an occy.

Getting it out

The tap arrangement changes daily life more than people expect.

A tap you can operate with one hand, at a workable height, with a container underneath, is the difference between rinsing a plate under running water and lifting a 20-kilogram jerry every time.

The simple version is a jerry on a tilting bracket. The better version is a 12V pump plumbed to a tap at the rear of the vehicle or at the kitchen. A pump is a small load and it makes the whole setup usable. See dual battery and 12V systems for the power side.

Keep a separate, clearly marked tap or container for drinking water if you are also carrying non-potable water for washing.

Keeping it drinkable

New containers leach. Food-grade plastic tastes of itself for a while. Fill, stand for a day, dump, and repeat two or three times before the trip. Discovering this on day one is a miserable way to find out.

Keep it dark. Sunlight drives algal growth, which is why quality water containers are opaque. A clear container in the sun grows green within days.

Keep it full. Air space in a partly empty container is where problems start. Consolidating into fewer full containers as you use water is good practice.

Clean between trips. Rinse thoroughly and dry completely. A container put away damp and sealed develops a smell that is very hard to remove.

Do not mix supplies. Adding questionable water to a clean tank contaminates the lot. Treat first, then transfer, or keep them separate.

Bore water

Across much of inland Australia the available water is artesian. It is often hot, heavily mineralised and unpleasant, and mineral content is not something a standard filter removes.

Plan bore water as washing and cooling water, and keep your drinking supply separate. Filling a drinking tank from a bore is how a good tank ends up tasting of sulphur for the rest of the trip.

A working setup

For two people doing remote travel:

• An under-body or canopy tank of 60 to 80 litres as the main supply
• Two 20-litre jerry cans as separate backup, secured low
• A 12V pump and a tap at the rear
• One clearly marked drinking container that never gets used for anything else
• A filter and chemical treatment for anything sourced along the way

That is roughly 100 to 120 litres split across three failure points, which is enough for a week for two with contingency, and it costs a bit over a hundred kilograms of payload. Budget for it deliberately rather than discovering it at a weighbridge.