Water Usage

Indoor Water Usage

On average, a three-person household uses approximately 165 gallons of water daily.  Review the chart below:

Toilet Flushing (older models) 3.5 gallons per flush*
Shower (water running) 25 gallons per 5 min. shower
Bath (full tub) 3.6 gallons per day
Laundry Machine more than 20% of all water in the home
Dishwasher 4-6 gallons fully loaded
Faucet 26.3 gallons per day
Brushing Teeth 4 gallons (tap running) per use
Washing Hands 2 gallons (tap running) per use

*The rate of consumption for water-saving devices or products significantly varies.  Please check the plumbing fixture package to determine the item's efficiency.

Outdoor Water Consumption

When warm weather arrives - and you water the lawn and garden, let the kids run through the sprinkler, or fill up their kiddie pool - your water usage can spike, as you can see from this table:

Hose Size LBS.  Pressure Per Sq Inch Time Gallons Used
1/2 Inch 60 1 Hour 630
5/8 Inch 60 1 Hour 1,020
3/4 Inch 60 1 Hour 1,860

Irrigation Systems

An irrigation pop-up station system uses approximately 16 gallons of water per minute.  Here is an example of how to calculate monthly irrigation water usage:

Number of Minutes x Number of Stations/Zones = Total Minutes
Total Minutes x Gallons per minute = Total Gallons used per watering cycle
Total Gallons per cycle x Number of days per month you water = Total gallons used per month


15 Minutes x 8 Zones = 120 Total Minutes
120 Total Minutes x 16 Gallons per minute (above) = 1,920 Total Gallons used per watering cycle
1,920 Total Gallons per cycle x 8 days per month you water = 15,360 Total gallons used per month

Calculating the Distance of Outdoor Spray Head Usage

Below are diagrams that you can use to calculate how much water usage in Gallons per MInute for the various types of spray heads typically used for irrigation.

Spray Head Throw Distances
This illustration shows the arc and range of various spray heads, which generally come in 5', 8', 12', and 15' "throw".  Each spray head should spray water just far enough to reach the next spray head.  If correctly set, the entire yard should get relatively even watering.

Spray Head Angles and Flow
This chart shows water use in Gallons per Minute (GPM) for the different types of spray heads used:

Sample Yard Irrigation Layout for Calculating Water Usage
This illustration is an example of a relatively standard 3-valve sprinkler system.  To calculate the total water usage, count the number of each type of spray head and multiply by the Gallon per Minute usage for each station.  Add the totals for all three stations to get the total water usage per minute for the entire yard.


Watering with a typical sprinkler using a standard 5/8" garden hose for one hour uses about 1,020 gallons of water; if watering three times per week, that's about 12,240 gallons per month.  If you run the sprinkler three times per week during a 90-day billing cycle, you will add approximately 36,000 gallons of water to your usage.

Product Duration Frequency Gallons Per Month
Irrigation System 15 min (with 8 zones) 2 times/week 15,360
Sprinkler 1 hour 3 times/week 12,240