Turning off the water as you brush your teeth is a no-brainer. A standard faucet can use about 2 to 3 gallons of water per minute, so it saves considerable water to shut it off as you do your thing, then turn it back on to rinse. Do the math: turning off the faucet saves up to 20 to 30 gallons of water per person per week. For a family of four, this can translate into over 6,000 gallons of year! That’s considerable savings—both for the environment and your wallet.