RV Water Conservation: Stretch Your Fresh Tank Twice as Far

How much water RVers really use

The average American household uses 80-100 gallons of water per person per day — mostly for outdoor use, toilets, and long showers. RVers can't get away with that. A 40-gallon fresh water tank holds, at most, half a day of stick-built habits.

The good news: with deliberate but not painful changes, most people can cut water use by 50-70% without feeling deprived. Full-time boondockers regularly stretch a 40-gallon tank to a week or more for two people. Here's exactly how.

Where the water actually goes

Before reducing anything, know where you're spending. In a typical RV without conservation tactics:

Two takeaways jump out. First, showers dominate — they're more than half of total water use. Second, drinking and cooking are essentially fixed; you can't safely reduce them. Conservation effort should focus where the gallons live.

Tactic 1: The navy shower (saves 60% per shower)

A "navy shower" is the technique sailors used on long voyages: water on to wet, water off to soap, water on to rinse. It cuts a 5-minute shower from 10-15 gallons down to 2-3 gallons.

The transition is easier than people expect. The trick is a quality shower head with a thumb-operated pause valve (often called a "trickle" valve) that maintains water temperature when you stop the flow. The Oxygenics Body Spa and the Dura Faucet RV-150 are both popular — under $40, install in 5 minutes.

One small habit shift makes navy showers comfortable: warm the bathroom first by running the water briefly into a bucket before getting in. The bucket water gets used to flush the toilet later (more on that next).

Tactic 2: Flush with gray water (saves 5+ gal/day)

Toilet flushes are pure waste — you're sending fresh, drinkable water down to mix with sewage. Replacing those flushes with already-used "gray" water saves both fresh water and reduces gray tank fill rate.

The simple version: put a small bucket (1.5-2 gallons) under the bathroom sink. Use it to catch hand-washing rinse water and warm-up shower water. Pour into the toilet bowl to flush. A flush takes about 0.5-1 gallon by hand, less than the toilet's pedal-flush water.

This sounds gross until you do it once. Soapy hand water is far cleaner than what's sitting in the bowl already. Most full-timers who try it adopt it permanently.

Tactic 3: Wash dishes in a basin, not under running water

Running water down the drain to wash a single plate uses 1-2 gallons. Two plastic dish basins (one for soapy wash, one for rinse) get the same plate clean with about half a gallon total.

The wash basin water can be reused for several rounds before it gets too dirty. The rinse basin water, when finally dumped, can go to the toilet (saves a flush) or onto plants outside (legal at most boondocking sites, illegal at developed campgrounds).

Bonus: pre-wiping plates with a paper towel before washing dramatically reduces the soap and water needed. Compostable bamboo paper towels work well and weigh almost nothing.

Tactic 4: Shut the faucet during teeth and hand soaping

This sounds obvious but most people don't do it consistently. Brushing teeth with the water running uses ~1 gallon. With the water off and only used for the rinse: 0.1 gallon. Same for soaping hands — turn it off while you lather, on for the rinse.

For households of two adults brushing twice a day plus a few hand washes, this single habit saves 1-2 gallons per day. Doesn't sound like much. Across a week of boondocking it's a full extra day on the tank.

Tactic 5: Use campground showers when available

If you're at a campground with shower facilities, even a paid one ($1-3 for a token), use them. A $3 hot shower buys you 10+ gallons of fresh water still in your tank for cooking and drinking. On a long stay, that math wins by a wide margin.

Even better: some boondocking spots are within reasonable distance of a truck stop or gym (Planet Fitness has unlimited showers on a $25/month plan that's popular with full-timers). A weekly shower-and-laundry run keeps your fresh tank lasting weeks instead of days.

Tactic 6: Catch water in unexpected places

Several easy "catches" add up:

• Rinse water from washing produce. Use a colander over a bowl. The bowl water flushes the toilet.
• Coffee maker rinse water. Same.
• Ice cubes that didn't make it into a drink. Same.
• Dehumidifier output if you have one. A dehumidifier can produce a gallon of water a day in humid climates — not drinkable, but fine for flushing or rinsing tools.

The conservation comparison

Here's what the same two people use under three different regimes for one week:

The shift from "normal" to "boondocker" almost halves water use, which usually doubles the time you can stay off-grid. None of the tactics above involves real discomfort — just a few habit shifts and a $30 shower head.

Frequently Asked Questions