Being the owner of an inground sprinkler system I can attest to the convenience as opposed to the old school method of hand watering grass and a garden or manually moving a sprinkler around as needed. The question is how much water a sprinkler uses when compared to other sprinkler systems and whether or not they save on both time and water usage.
Consumer sprinkler heads are typically capable of water flow from 0.04 – 4.58 gallons per minute (gpm) per head or about 0.12 – 13.74 gpm per zone. Your home sprinkler system’s capacity depends on the number of sprinkler heads you have, the total zones and your water pressure.
The installation of an average underground home sprinkler system ranges from around $1,700 – $3,500 depending on the number of sprinkler heads and zones you choose in addition to the system that you purchase. A per sprinkler head installation cost of a system may range from $30 – $80 or more per head depending on specifics and whether or not you do the work yourself.
How many gallons per minute does a sprinkler system use
Each individual sprinkler head can typically pump 0.04 – 4.58 gallons per minute depending on the model. Sprinkler manufacturers produce dozens of models that differ in design depending on your requirements and available home water pressure. Each sprinkler head is then organized in a zone that typically includes 1-4 sprinkler heads that operate together at the same time.
With that in mind, here are examples with various sprinkler head’s gallons per minute (gpm) flow rates and a comparison of a zone with 1 head, 2 heads, 3 heads and 4 heads to show total expected water flow in gallons per minute.
Sprinkler system water usage for 1 – 4 sprinkler head zones in gallons per minute (gpm)
| Sprinkler head gpm | 1 head | 2 heads | 3 heads | 4 heads |
| 0.04 gpm | 0.04 gpm | 0.08 gpm | 0.12 gpm | 0.16 gpm |
| 0.16 gpm | 0.16 gpm | 0.32 gpm | 0.48 gpm | 0.64 gpm |
| 0.64 gpm | 0.64 gpm | 1.28 gpm | 1.92 gpm | 2.56 gpm |
| 1.28 gpm | 1.28 gpm | 2.56 gpm | 3.84 gpm | 5.12 gpm |
| 2.56 gpm | 2.56 gpm | 5.12 gpm | 7.68 gpm | 10.24 gpm |
| 3.34 gpm | 3.34 gpm | 6.68 gpm | 10.02 gpm | 13.36 gpm |
| 4.58 gpm | 4.58 gpm | 9.16 gpm | 13.74 gpm | 18.32 gpm |
From the table above, you can get a sense as to how much total water your sprinkler system may use depending on what size sprinkler heads you have and how many sprinkler heads are in each zone.
You can also choose sprinkler heads that have various water flows of 0.08 gpm, 0.38 gpm, 0.58 gpm, 1.08 gpm, 3.70 gpm and more. It really depends on what you are watering (plants, grass), how big the area is, and your available water pressure.
Depending on how much you have to water and the size of your property, you will need a certain number of sprinkler heads that meet your needs in a layout that takes into consideration the dimensions of your property.
Your sprinkler system’s water flow capacity
Your sprinkler system’s water flow capacity is constrained by your home’s water flow which we’ll discuss below. Your sprinkler system’s total usage in gallons of water per minute is determined by the:
- Number of sprinkler heads you have
- Number of zones you have
- Type and style of sprinkler heads you have
- Time and frequency you run your sprinkler system
Rotating sprinkler heads are the most common style but they come in many options in terms of water flow, water radius, water arc, sprinkler design, sprinkler height and recommended operating water pressure.
Sprinkler head specifications for home use
Major sprinkler manufacturers produce catalogues of 100+ pages detailing the various specifications of available sprinkler heads. There are plenty to choose from.
Typical product ranges include the following:
| Feature | Product range |
| Water flow | 0.04 gpm – 4.58 gpm |
| Water radius | Up to 360° |
| Water arc | 0°-360° |
| Sprinkler design | Stationary nozzle, rotating nozzle, stream spray, dripline, bubble spray, etc. |
| Sprinkler height | typically 3/4″ up to 5″ above ground |
| Recommended operating water pressure | 20 psi – 50 psi |
How you can adjust your water usage and water flow
Once you have your sprinkler system set up there are several ways you can impact your water usage:
Time: Obviously the longer and more frequently you run the sprinkler the more water you will use. That’s simple enough. You can also impact the water usage by running certain zones more or less frequently than others with the scheduling feature. Some areas of your yard may be shaded which may require less water and others in direct sunlight which need more.
Rain sensor: Some systems come with a water sensor which monitors rain in your area and overrides any schedule you have set up. So if the sensor notices that you have had significant rain recently, it will skip any scheduled watering to save water and thus money. No point in using the sprinkler if your lawn and garden are already saturated from the rain.
Sprinkler head adjustment: With modern rotating sprinkler heads you can adjust the arc of water that comes out of each head so you can alter the water angle up or down as needed. The top of each sprinkler head usually has a slot for a flat head screwdriver that enables you to increase or decrease the angle of the water flow and how the water comes out.
Sprinkler system heads and zones
An underground sprinkler system is made up of zones which are turn made of individual sprinkler heads.
Sprinkler head
An individual component that typically pops out of the ground and sprays water but is part of a larger zone. Sprinkler heads are normally spaced no more than 15′ apart to avoid creating dry zones that don’t receive any water.
Sprinkler “heads” might be an actual rotating sprinkler head that turns, one that is stationary, a bubbler that floods a tree or garden area or even a rubber dripline hose with small holes to slowly drip water in a garden area. You can also set your sprinkler system up with a combination of these styles.
Sprinkler zone
A zone is a group of sprinkler heads that operate at the same time. So a zone might have 3 or more sprinkler heads operating at one time. It depends on the water capacity your system can supply.
Depending on how many zones you have and the sophistication of your sprinkler system, you can schedule the sprinkler zone(s) to run on certain days and times as needed. When Zone 1 is operating, the other zones do not. When Zone 1 finishes its cycle, the next zone that is scheduled starts up and so on. This is done to take into account that you do not have enough water pressure to run all zones simultaneously.
Of course even if your sprinkler system is capable of a certain flow rate it is constrained by the water flow rate that the faucet the system is attached to is capable of providing.
How do you determine how many sprinkler heads you can put on each zone? That’s for your chosen sprinkler company to help with. Get them to do that work on your behalf as they have experience doing this for their customers as part of the design of your sprinkler system.
If you’re going to install your sprinkler system alone, you’ll need to determine your home water flow and water pressure rate.
Determine your home water flow rate per minute
How much water can your home backyard faucet supply to your inground sprinkler system?
Water flow rate = 300 / Number of seconds it takes to fill a 5 gallon bucket where 300 represents 5 gallons x 60 seconds in a minute.
To figure out the maximum rate of water flow that your sprinkler has access to, you can easily measure it by doing the following:
- Ensure no water is being used in the house.
- Take an empty 5 gallon bucket and put it under the outside backyard faucet.
- Open the faucet completely and time how long it takes to fill the 5 gallon bucket completely.
- Take the number of seconds it took to completely fill your bucket and divide it into 300 as the equation above shows. So if it took 30 seconds to fill your bucket your water flow rate is 300 / 30 = 10 gallons per minute.
So in this case, your system is capable of producing 10 gallons per minute. You can now work backwards to figure out how many sprinkler heads are capable of being run at one time. Typically a zone will include 1-4 sprinkler heads.
It should be noted that when your sprinkler is running, if you turn on another heavy water consuming appliance like a tap, washing machine or garden hose, the pressure from the sprinkler system will drop to the point where the system may not have enough pressure to operate.
Measure your water sprinkler water usage
While there are suggestions online about setting up water catching buckets, turning on your water sprinklers, catching the water in the buckets and then measuring the buckets to see how much water was used, there is another way to get a quicker reading with less work involved.
- Ensure no water is being used in your house.
- Check your water meter and write the current reading down on a piece of paper.
- Run your sprinklers for a period of time such as 5 minutes.
- Recheck the water meter and write down the new reading. For 5 minutes of sprinkler operation, you can divide your meter reading by 5 to figure out your per minute water usage. Or you could multiple that 5 minute result by 12 to get the 1 hour (60 minute) water usage for your underground sprinkler system.
You may choose to run the sprinkler for 10 or 20 minutes to get a more accurate reading and then figure out the per minute or per hour reading based on that.
Final thoughts
Major inground sprinkler system manufacturers include Toro, Rain Bird, Weathermatic, Orbit Irrigation, Hunter and more.
How much water does a sprinkler system use per minute? As you can see above, there are a number of factors that determine this especially given the wide variety of sprinkler heads with different flow rates available.
How often should you water your lawn and garden with your sprinkler system? Depending on your climate and rain fall, you’ll probably find that watering your lawn and garden 20 minutes x 3 times per week will give you around 1″ of water which is what you’re looking at achieving.
Giving your lawn a good deep soaking is preferable to giving it light ones as the longer waterings enable the moisture to penetrate the ground and encourages deeper root growth.
Watering in the morning before 10am prior to direct sun is the best time to water. When you water at night when the sun is down, the lawn remains damp and can lead to disease and mushroom growth. If you have to water later in the day try to do it in the 4pm – 6pm time frame when the sun has gone down but before it has cooled off.
If you combine a schedule with the use of a rain sensor, it’ll ensure you aren’t over watering your lawn and garden and thus wasting money. The rain sensor feature is a great way to keep utility costs down while still maintaining a nice lawn and garden.