The average usage of water in a residential sprinkler system is between 12 – 30 gallons per minute depending on the type and size of the sprinkler head.
Typical sprinkler flow rates may vary from 4 gallons per minute (gpm) from a 5/32-inch nozzle at 30 pounds pressure to over 11 gpm from a 7/32-inch nozzle at 70 pounds pressure. The nozzle size is usually stamped on the nozzle. Wheelmove systems typically have 3/16-inch nozzles.
Q = A√(2gh)
The formula calculates the discharge flow from the nozzle (fire sprinkler, water mist or deluge nozzle) in its most common form. If we are given the head pressure and k-factor, we can also calculate the k-factor or the pressure required with this formula.
The typical residential water flow rate for small households is between 6-12 gallons per minute, so unless you plan to add extra kitchens, bathrooms, or laundry rooms to your home in the future, your home will never need to exceed that final GPM, assuming your flow rate is already normal.
On average, it will take 30 minutes to get a half inch of water. So, 20 minutes, three times per week will give a lawn about an inch of water. This formula works best with healthy, well-cultivated soil.
Sprinklers generally cover up wider ground and spread out water at a slow yet steady pace, which makes all the soil moisturized evenly and soaked underground. A watering hose takes time to cover space and can clutter the soil if there's too much water.
Watering with a typical sprinkler using a standard 5/8" garden hose for one hour uses about 1,020 gallons of water; if you water three times per week, that's about 12,240 gallons per month.
They report that typical lawn sprinkler irrigation systems may require 12-gallons per minute (gpm) to operate properly. They indicate 10 gpm is the minimum for fire protection, with 20 gpm being preferred.
The number of sprinklers needed is based on the size of each room; in residential systems the goal is to spray at least 0.05 gallons of water per minute per square foot of floor area. Coverage per head ranges from a low of 12 feet by 12 feet to a high of 20 feet by 20 feet.
Based on this information, expect a total pressure drop of about 15 psi (5 + 4 + 3 + 2 + 1) from the utility supply line to one of the sprinkler heads. If the utility is delivering water to your house at a pressure of 60 psi, then expect a pressure of about 45 psi at each head.
Generally, spray heads use about 0.75 gpm for ¼-circle, 1.5 gpm for ½ circle, and 3.0 gpm for full-circle heads. "Rotor" style heads use 2 to 5 gpm each, for most residential applications.
System maintenance can help save you a lot of money and water! Cracks in pipes can lead to costly leaks, and broken sprinkler heads can waste water and money. You could be losing up to 25,000 gallons of water and $280 over a six-month irrigation season! Now is the perfect time to spruce up your irrigation system.
To calculate the amount of water you use, multiply the width times the length of your yard in feet to get the number of square feet of area. Then multiply that figure by 0.623 to come up with the number of gallons used (or use our calculator below).
Uniformly applying water helps the soil absorb the water at its own pace. Watering every day is not advised. It should be done 2 to 3 times per week only to prevent a shallow root system. If possible, water during the early morning hours to ensure that the lawn dries entirely before nightfall.
How Much Water to Use. When watering an established lawn, it's typically recommended to water until the top 6 to 8 inches of soil (where most turfgrass roots grow) is wet. Most lawns need 1 to 1.5 inches of water per week—either from rain or watering—to soak the soil that deeply.
Not Adjusted to Properly Cover the Right Areas
If one sprinkler head sprays over another one, this leads to overwatering and wasted water and money. Your grass and plants will absorb what they need to survive. Water they don't need will sit and pool on the surface of your grass.
Most sprinkler systems use around 12 gallons of water per minute. If left unchecked, that could mean a lawn filled with standing water. A general rule of thumb is to water three days a week in the spring and summer and two days a week in the fall and winter.
Start by accepting the fact that “lawns don't waste water, people do!” If you water your yard only when it needs it, for example, you could save between 750 and 1,500 gallons of water a month. Encourage the grass to grow deeper roots by watering it sparingly.
The best time to water grass is in the early morning, ideally before 10am, or in the late afternoon. During these times, the temperature is cooler, and the wind and sun are less intense, which allows the grassroots to absorb the moisture before it evaporates from the soil.
Avoid watering grass on a hot afternoon when it's 95 degrees or higher. The best time to water grass is at dawn or in the early evening. Water deeply three times a week instead of a little water daily. Test whether your sprinkler system is watering your lawn evenly.
The water flow rate is the measurement of how fast treated water will come out of your faucets throughout your home. It's measured in gallons per minute (GPM). The average household has a water flow rate of 6 to 12 GPM. Therefore, most households use roughly 100 to 120 gallons of water each day.
Open your main water valve.
Your house has a main water valve, usually located near the meter; the valve controls the flow of water into your home's pipes. Find the valve and check to see if it's completely open. Opening a half-shut valve is one of the quickest ways for increasing home water pressure.