Estimating Residential Water Usage Guidelines

1. Drinking & Cooking Water: 1/2 gallon to 1 gallon/person/day.1000 gallons can serve 3 to 4 people for a year. This includes drinking water, coffee, tea, cooking rice, pasta and soup, water for the family pet & maybe the African Violet.

2. Washing Dishes in the Sink: A) 5 gallons/load if washing and/or rinsing in pan or sink; B) 30 gallons per load with tap running. A second source says washing dishes can vary from 15 to 60 gallons.

3. Misc. Use at Kitchen Sink: Washing hands, delicate clothes, the pet, filling cleaning bucket, watering houseplants, et cetera. We estimate 1 gallon/person/day.

4. Floride Solution Estimate: # FS/DW will use the amount you use through your water purifier.

5. Automatic Dishwasher: A) Short cycle: 7 gallons; B) Full cycle: 16 gallons.

6. Washing Machine: A) Short cycle, low water level: 27 gallons; B) full cycle, top water level: 60 gallons.

7. Shower: A) Lo-flow shower head: 2-3 gallons/minute; B) hi-flow shower head: 5-7 gallons/minute. The average shower lasts 7.5 minutes.

8. Bath: A) Minimal water level: 10-12 gallons; B) full: 36 gallons.

9. Washing Hands: A) Fill basin: 1 gallon; B) Tap running: 2 gallons.

10. Brushing Teeth: A) Wet brush, brief rinse: 1/2 gallon; B) tap running: 10 gallons.

11. Toilet: A) Ultra-low flush toilet: 1.6 gallons; B) standard toilet: 3.5 - 5 gallons/flush.

12. Washing Car: A) 1/2" hose running: 8 gallons/minute; B) using shut-off nozzle: ?

13. Cleaning Pavement: A) With 1/2" hose: 8 gallons/minute; B) with broom: 0 gal.

House Usage Percentages: Toilet 36%, laundry 20%, bath & shower 28%, dishwashing 7%, misc. usage of indoor faucet 5%, cooking and drinking 4% = 100%. State of California figures.

Indoor vs. Outdoor Percentages: Mild climate (central CA coast) suburban lot: Indoors 77%, Outdoors 23%. Mild climate apartments: Indoors 80%, Outdoors 20%. All CA climates: Indoors 53%, Outdoors 47%. You can estimate your own with 1 years records using the minimum month method. Find the lowest month, probably one of the winter months when you are doing no outdoor watering. Subtract that amount from all the other months. Add those 11 remainders together and compare that total to all the usage for the year.