Unfortunately, there is no rating system for kitchen faucets. This is because kitchen water usage is deemed (correctly or not) to be governed by habit and equipment rather than a faucet's flow rate. In other words, you use more water because you cook kilos of spaghetti in huge pots than because that water comes out of the faucet quickly!

Real-world testing of any kind results in one important conclusion: water savings in the kitchen come more from the control of the flow than its rate. Systems that can be shut off with a foot or knee, or which have special or automatic flow stoppers, will do more to reduce water wastage than anything you can do with the flow rate.

If you're installing a greener kitchen, choose faucets with lever controls rather than twist tops as a bare minimum. Ideally, you should target pedal controls or other special systems, such as the "wave-on wave-off" sensor kits produced by Stern Engineering and other providers.

The other major water-guzzler in the kitchen is your dishwasher, whether it's an appliance or a person. We've covered those in their own article.

If you're really interested in how much water it takes to produce everything you use in the kitchen (or elsewhere), there's a website called Water Footprint that will give you all the scary details. It takes 1,000 liters of water to produce a liter of milk, 2,500 liters to produce a kilo of rice and an astonishing 15,400 liters to produce a kilo of beef!