Washing laundry at home is a significant use of water, accounting for up to 40% of total household water consumption. This is partially due to the incredible water demands that a typical top loader uses, 40-50 gallons per load! After a year spent going to the laundromat and being increasingly disgusted by the cost and how poor a job the "high efficiency" washers did (after all, how high is the efficiency when the machine doesn't do the job it was designed to do?) we have returned to using a wringer washer. I spent our early married years using a wringer, we've also washed clothes by hand with a plunger and scrub brush- which is hands down the cleanest our clothes have ever gotten.
The wringer washer takes 16 gallons to fill, in that water I wash at least 3 loads in succession beginning with the lightest/least soiled clothes and progressing to dirtier/darker clothing. As each load is wrung it is put in a bucket or basket, after the 3-4 loads are washed the tub is refilled with rinse water, each load is rinsed, wrung and then hung. The rinse water then becomes the wash water and the cycle starts again. To fill my particular clothesline I can wash 6 loads, so water consumption for me equals 48 gallons (16 gallons to wash, 16 gallons to rinse which is also the next 3 load's wash water, and 16 more gallons to rinse.) That works out to 8 gallons per load of laundry.
To my rinse water I add a splash of vinegar, we don't like our clothes coated with synthetically scented petrochemicals, then we line dry. In the Winter (which here is mostly rain) we use lines strung on the porches, drying racks indoors and/or lines strung through the living room. It takes around 12 hours for jeans to dry, but that's balanced by increasing humidity in the house and the fact that my kilowatt usage is zero.
I like that our laundry method leaves a gentler impact on our planet, but I like the cost savings even more. We were spending around $30/week at the laundromat. Should we want to take our laundry system off grid this washer could be converted to bicycle power in about an hour. I found one of my wringer washers on Craig's List and the other at an auction, I paid $75 and $125 for mine. I can't image a laundry system that I'd be more pleased with than this, it has everything: clean clothes, low energy use, and very low water consumption!