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Tips for Measuring Water Usage


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Below are suggestions for how you might estimate the amount of water used (gallons) for each of the activities in the Personal Water Use Chart. However, you may be able to come up with better ways of estimating the amount of water used. Are there any additional activities that are not listed on the chart that you use water for at home? If so, be sure to include those too.

Washing face or hands Get a bucket and a stop watch or watch with a second hand. Turn on a faucet so the water comes out like it usually would when you wash. Put the bucket under the faucet and at that very same moment start timing. Wait until exactly one minute is up then turn off the faucet. Pour the water into an empty gallon container and estimate how many gallons of water you used. This will tell you the flow rate (gallons per minute) of your faucet.

Next, time how long it takes to wash. If you measure this in seconds you will need to convert the time to minutes. Multiply the flow rate X time for activity and you will have estimated the amount of water used to wash.

Taking a shower Follow the same procedure as for washing your face or hands. However, you might need to get an adult to help you. The adult should hold the bucket near the shower head to collect the water. You might need a few buckets for this!
Taking a bath Fill up the bathtub to its normal level. Using a ruler, measure the length and width of the tub and then measure the height of the water in the tub. Multiply the length X width X height of the water to get the volume of water in the tub. If you take the measurements in inches, your volume will be in cubic inches. You need to convert the volume of water in the tub to gallons. One of the unit conversion calculators in the Reference Material section may help. The is the number of gallons used to take a bath.
Brushing your teeth Follow the same procedure as for washing your face or hands. When you determine the time for brushing your teeth make sure you use only the time when the water is on.
Flushing the toilet The water used to flush the toilet is stored in the rectangular tank right behind (or above) the toilet. Open up the lid and look inside. An adult should help you do this. Using a ruler, measure the length and width of the tank and then measure the height of the water in the tank. Multiply the length X width X height of the water to get the volume of water in the tank. If you take the measurements in inches, your volume will be in cubic inches. You need to convert the volume of water in the tank to gallons. One of the unit conversion calculators in the Reference Material section may help. The is the number of gallons used to flush your toilet.
Shaving If shaving is done with the water running, determine the amount of water used by estimating the flow rate of the faucet and the time it takes to shave as in the procedure for washing your hands above. If shaving is done by filling up a basin, then fill the basin to its normal level and scoop out the water into a gallon container. Then estimate the number of gallons needed to shave.
Getting a drink Determine the volume of the glass that you normally use to drink. Convert its volume to gallons using one of the unit conversion calculators in the Reference Material section.
Cooking a meal As you cook a meal, estimate the amount of water used to rinse food, boil food, or add to food. Keep a gallon container handy to pour water into to measure as you go along. Also, if you use running water at any point, measure the flow rate of the faucet and the time the water runs as you did for washing your hands above.
Washing dishes by hand If washing is done with the water running, determine the amount of water used by estimating the flow rate of the faucet and the time it takes to wash as in the procedure for washing your hands above. If washing is done by filling up a basin, then fill the basin to its normal level and scoop out the water into a gallon container. Then estimate the number of gallons needed to wash the dishes.
Running a dishwasher Look in the owner's manual to see how many gallons the dishwasher uses. If the flow rate of the water is given instead, then multiply this by the time the dishwasher runs (wash and rinse cycles only).
Doing a load of laundry Look in the owner's manual to see how many gallons the washing machine uses. If the flow rate of the water is given instead, then multiply this by the time the washing machine runs. If the manual is not available, try measuring the volume of the machine and converting to gallons or using a bucket to collect the waste water (before it goes down the sink) and measure the volume this way.
Watering a lawn If watering is done with a hose, determine the amount of water used by estimating the flow rate of the faucet and the time it takes to water as in the procedure for washing your hands above.
Washing a car If washing is done with a hose, determine the amount of water used by estimating the flow rate of the faucet and the time it takes to water as in the procedure for washing your hands above. If washing is done with buckets, estimate the number of buckets and the volume of each bucket in gallons.