how many gallons of water does a human need
3 gallons per flush x 6-8 flushes per day = 18-24 gallons2. A full tub is about 36 gallons. Depending on efficiency of dishwasher: 4 to 10 gallons. Hygiene (washing face, brushing teeth, etc.) 2.5 gallons. The average person uses 101.5 gallons of water Per day. Hereâs How: 8 glasses of 8oz cups of water is recommended 1 gallon.