Of course, when compared to the handwashing method, dishwashers do seem to use a lot of water since it is constantly spraying water on the dishes. However, this can’t be said for most energy star dishwashers. With the handwashing method, you could use up to 20 gallons of water per load, but energy-efficient dishwashers use far less than that amount for cleaning. Therefore most quality dishwashers out there use less amount of water to clean up your dishes.