Monday, September 26, 2022


New RVer asks: Should I carry water in my tank when traveling?

By Russ and Tiña De Maris

Should I carry water in my freshwater tank when traveling? If I do, is there anything special I should do?

It’s a question that comes up a lot among new RVers. The “right” answer (and there isn’t really a “right” or “wrong” one here) depends on your RV lifestyle.

First, a bit about water: In the RV world you need to remember – it’s heavy. At eight pounds to the gallon, a typical 30-gallon freshwater tank will boost the weight of your tow (or of your motorhome) by almost 250 pounds. With the price of fuel, that’s no small consideration. If your rig is already near the “limit” of its gross vehicle weight, casting off 250 pounds is a way to lighten up quickly.

But then there’s that lifestyle question. Are you headed out with your RV to boondock away from utilities? If you are, and there’s no water close to your boondocking location, you may have no choice but to travel with the water on board.

On the other hand, if you’re headed for an RV resort with full hookups, or a campground with a “known” good water supply, you can skate in and fill up (or hook up) on arrival. There are some RVers who disdain this idea. Many are the stories of RVers arriving at the campground only to find that water supply is “down” for a couple of days, or tastes so bad that it’s nearly unfit for consumption.

Perhaps a compromise is in order. No matter what our plans, we always try to see to it we have a few gallons in the tank. If we hit problems on the road and find ourselves stuck somewhere waiting for, say, repairs, we have enough water on hand to keep us going for a few days if we’re very conservative with our consumption. If you call the campground before you arrive and determine the water is working then, take your few gallons and go; fill up on arrival even if you’ll have hookups just in case the system goes “kaput” while you’re there.

Of course, the idea of “dumping” water on the ground to lighten your load seems like a pretty serious sin, especially to those of us who frequent desert country. So if you fill on arrival, plan and time your consumption so that much of that tanked water can be used while you’re in the campground so that little is wasted if you decide to jettison the excess on leaving.

photo: steve_lodefink on



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Jason Anderson
4 months ago

Are there baffles in the tank to reduce the extensive sloshing, adding profound stress to the simple design of the supports?

2 years ago

Isn’t the question more about the tanks ability to carry the load than etiquette of dumping water? is there harm to the tank or system if an rv carries a load of water around????

2 years ago

If you break down on the road, or arrive at a campground where the water is off due to a break (fairly common) you will wish you had water on board.

Jason Anderson
4 months ago
Reply to  Darrel

Carrying a 5 gallon tank in the truck, until able to arrange additional water

2 years ago

Our class A weighs 33,000 pounds. 8 x 90 gallons of water equals 720 lbs. An extra 720 pounds makes no difference in fuel economy or handling.

George OBriain
2 years ago

I live on the west coast. Our RV is also our home in a disaster. We keep water in case of an earthquake, tsunami or whatever disaster we encounter. Forest fires is a disaster we’ve gone through. Remember the Boy Scouts motto, “Be Prepared”. I’ve travelled with both a full and empty water tank and in an A Class there was no difference in fuel consumption.

Ed D.
2 years ago

I travel with a full tank of water. I usually go to places that have no water hook-ups at the site. And I don’t want the hassle of filling up at a campground’s water fill area, especially when it’s on a busy week-end/holiday. And I don’t think my milage is any worse when I do carry water.

2 years ago

For what it is worth after 50 years of RV travel, I do not recall ever leaving home base without a near full fresh water tank, filling it along the way as we deem the supply SAFE. Anyone who has seen how some people treat the fresh eater supply tap in some camping situations will fully understand why we leave home with a full tank.
We condition the RV fresh water tank every fall when we shut down, and flush it thoroughly in the spring as part of maintenance before we head out again.
Back to the campground source water for a moment. I carry a full spray bottle of Hydrogen Peroxide, to clean the tap and surrounding pipes etc, before I go near it with my fresh water hookup.

2 years ago
Reply to  Alvin

I should have mentioned above that the lady only uses the best bottled water we can buy, which we carry separately in the coach to make coffee, tea and cook with.

2 years ago

It’s best to know your RV current weight prior to adding any water. There is plenty of discussion about Cat Scales and individual tire weighs but the bottom line is that if you are involved in an accident, you can pretty much bet that everything will be considered. Including the GVWR versus actual. At 8 lbs per gallon, it might just put you over. We have a 42′ rig with a 109 Gal water tank. That would be over 800 lbs. When you full-time, it’s amazing how fast you can be over-weight with just “stuff”. There are times we travel with about 25 gallons. But most of the time, we wait until we get closer to the destination. A few places to look for water…

1) Truck Stops
2) Gas Stations
3) Many RV Parks (sometimes at a small fee)
4) Walmart (5 gallon bottles or sometimes in the Lawn and Garden Centers for free)
5) Home Depot (5 gallon bottles or sometimes in the Lawn and Garden Centers for free)
6) Ace Hardware (5 gallon bottles or sometimes in the Lawn and Garden Centers for free)
7) Individual Water Dispensing Stations (usually in a parking lot of a grocer)
8) Rest Areas

I’m willing to bet that there are many others on this post that can offer additional resources.

Our primary water (unless we know exactly what kind of water we are putting in the system and sanitize the system first) is bottled water.

Sink Jaxon
2 years ago
Reply to  TravelingMan

Yes, we always use bottled water for cooking/consumption also. No telling what contamination is in pipes. We were at a campground in north Texas last spring where the water was BROWN, even tho I let the water run for two minutes. Needless to say I didn’t even hook up to it.

Donald N Wright
2 years ago

I agree, it depends on where you are, or where you are going. Then again, I have been some spots where two filters didn’t help the taste of the water.

2 years ago

many years ago we would travel with just a few gallons in the fresh tank. then one late night we checked into an RV park/motel near Carlsbad Caverns. during check-in i spotted a flyer under a pile of tourist attraction ads. the flyer was a warning from the NM Dept of Public Health that the park’s water supply was contaminated with e-coli. the check-in clerk never said a word to us. we had planned to stay a few days but left the next morning. since that wake-up call we carry a full or nearly full tank of fresh water. the weight of our water represents about 3% of our rolling weight. be prepared.

Dave W
2 years ago

Our Montana has a 64 gallon water tank. 64 x 8.33 + 535 pounds. We seldom are without a CG site without at least water and electric so see no reason to haul that extra weight. Also, the HW heater holds 10 gallons (84 pounds) which is always full, but that too needs to be added into the GVW equation. We do carry enough in the FW tanks to flush the toilet though – how much – 5-8 gallons. If someone is concerned about a CG water’s quality – a good taste and sediment filter will fix that. If you are a boondocker – a different story though – we aren’t.

Wayne Caldwell
2 years ago

First, please realize I am not insulting nor attacking anyone. I see comments about carrying water in the RV tanks whether it’s a full tank of only a few gallons and then some bottled water. I’m looking at it that whether the water is in the tank or in a bottle, it still weighs the same. And if you even partially fill the tank, it’s cheaper than buying water in small plastic bottles that you have to ‘properly (in many locales)’ dispose of. Again, not attacking anyone’s thoughts or comments.

Walt & Mary Jean
2 years ago

During the past 20+ years of RV’ing my wife & I have experienced nearly every possible situation. With weight and mileage always a consideration, we have learned that 10-15 gallons of fresh water in our 45 gallon fresh tank is just about the right amount.
We have just enough water for non campsite bathroom usage or washing our hands. When some campgrounds water is not good enough for drinking, we always carry a case of bottled water, then when we find really good water at some RV Parks, we will add a little water to our fresh tank. After visiting 45 of the 48 States we have learned a lot.
Happy Trails

John vaughn
2 years ago

we do the same,as you and your wife,

Gloria Sluder
2 years ago

We carry 1\4 tank of fresh water to flush toilet. Bottle water to drink and 1 gallon for coffee. Till we get to final campsite.

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