Water Usage Comparison -- Residential vs RV Lifestyles

[William Briggs]

Daily Water Usage Per Capita Residential vs RV Lifestyles
Category	Residential (gallons per day) SOURCE: American Water Works Research Foundation, 1999	Recreational Vehicle (gallons per day) SOURCE: Various Internet Sources, and my own calculations	Comment
Toilet Flushes	18.5	1.5	The RV toilet is much more efficient than the residential toilet.
Clothes Washer	15	7.5	Very liberal estimate on RV usage; probably lower.
Showers / Baths	12.8	8.8	The U.S. Government limits the flow capacity of a showerhead to 2.2 gallons per minute. The water savings is due to the limited hot water available onboard the RV, resulting in quicker showers.
Faucet / Other domestic / Dishwashing	13.5	6	Varies significantly among individual RV'ers habits and lifestyles. I believe my estimate is reasonable.
Total Indoor Water Usage	59.8	23.8	For indoor uses, I estimate the RV will use only 40% the water of its sticks-and-bricks counterpart.
Leaks & Drips	9.5	0	The RV'er, due to the design of our systems, cannot abide with any leak on the fresh-water side of the system. Therefore, the average water wasted through leaks in the RV must be near zero.
Unknown	1.7	0
Outdoor	100.8	5	According to the AWWRF study, most of this “outdoor” usage involved watering lawns. Most full-time RV'ers do NOT maintain lawns (which was one of the prime reasons I chose the full-time lifestyle!).
Total Water Usage Per Capita	171.8	28.8	I estimate that the RV lifestyle uses only 17% of the water used in the comparable sticks-and-bricks lifestyle.

 

NOTE (1), GREYWATER GENERATION: I have compared my estimates on this chart with my actual usage among two different RV's. For two people spending a weekend in a fifth wheel, I found that the 76 gallon greywater tank would be about 75% full at the end of the weekend. Therefore, actual greywater generation, in my experience, would be 76 gallons times 75% divided by 2 people divided by two days equals about 14 gallons per person per day (compared to my estimate, above, indicating that greywater generation, less laundry, would be about 14 gallons per day). Therefore, I am confident that my estimate for greywater generation approaches real-life, at least for my particular water-usage habits.

 

NOTE (2) BLACKWATER GENERATION: Because the blackwater tank is allowed to fill to near-capacity before emptying, I am much more confident on my generation of blackwater. In my motorhome, I need to empty the 20-gallon blackwater holding tank every ten days, which is exactly 2 gallons per day of blackwater generation per day. Internet sources say I should be generating 1.5 gallons per day. Close enough. HOWEVER, last year whenever I would travel with my now-ex-girlfriend in a fifth-wheel, I calculated the blackwater generation to skyrocket -- toward 4 or 5 gallons per day per person. (When we broke up, I got angry and accused her of being full of "it" -- perhaps I have scientific proof she actually was?) Perhaps more likely, she rode the toilet's "rinse" pedal much longer than I do during a toilet flush.

 

NOTE (3) FRESHWATER USAGE: It would be advantageous to compare usage from the freshwater tank, to the estimates I have listed above. I don't do a lot of dry-camping, so I lack a "feel" for estimated freshwater usage per person, per day. However, the rare times I DO dry-camp, I figure about 15 gallons per person per day. My estimate above (less laundry & outside water) would predict 16 gallons per person per day. Close enough.

 

I would enjoy hearing especially from dry-campers, because they must necessarily calculate their water consumption carefully. Could said dry-campers inform me if my calculations on freshwater usage per day, is even close to their actual experiences?