Permaculture author Paul Wheaton demonstrates how hand washing a standard load of dishes can use just three litres of water. In comparison, a standard dishwasher uses 57 litres of water per load and energy-efficient dishwasher use around 34 litres per load.Video by Paul Wheaton.
It is said that using a dishwasher saves more water than doing a similarly-sized load of dishes by hand, but that is assuming you fill an entire sink with water before starting and running your tap to rinse throughout the process. If you instead start with your smallest items and use rinsing water to fill the washbasin you can wash dishes more efficiently by hand as shown above.
A side benefit of washing by hand is that you never have to rewash food items that a dishwasher was unable to remove.
Washing Dishes By Hand Vs. a Dishwasher [Permies.com]