Install low flow pre-rinse spray valves
Old pre-rinse spray valves can use 10 to 20 litres of water per minute. New standard ones use 6 litres per minute. WaterSense® certified pre-rinse spray valves consume a maximum of 4.8 litres per minute. Minimizing the amount of water used to rinse dishes saves both water and energy to heat the water. You could save over half the water you are using to rinse dishes.
Check the flowrate of your current spray valve by running it for 10 seconds. Capture that water in a measuring cup. Multiply the amount of water collected by 6 to tell you how many litres per minute your spray valve is using. If it’s more than 6 litres per minute, it’s time to replace it. While you are at it, check your taps for leaks and fix them.