This one's on so crystal clear, since it all depends on how you hand wash and on Model of dishwasher. Research by the British Government found that dishwasher get items cleaners and use about 75% less water. The key is having a modern model. Dishwashers built 30 years ago. Older model can use up to 90 liter of water a load. Modern model use as little as 9 liters.