How these Questions Affect Gallon Use: 1. Turning off the water saves about 0.5 gallons depending if your sink is new or older and turning off the water only takes around 0.5 gallons (older sink is about 2 gallons per minute and newer sinksare about 1 gallon per minute) 2. A shower takes about 2.5 gallons per minute if your shower head is new and about 4 gallons per minute if your shower head is older. 3. Conserving water is very important and many people don't realize how much water they use, over three days the estimated amount water used for a 6th grade science class of 26 kids used 8,665.95 gallons and that is only counting things that they used or things that their parents did for the student's benefit, like the student's laundry, or cooking for the child.