If you're getting a sprinkler quote, or just looking at the controller in your garage, you've probably seen the word "zones." It's one of the biggest factors in how a system is designed, and it's one that most homeowners never get explained.
Here's what zones are, why yards are split up, and how the right number gets decided.
What Is a Sprinkler Zone?
A zone is a group of sprinkler heads that are controlled together by one valve. When the controller runs a zone, the valve opens and every head on that zone turns on. When the time is up, that zone shuts off and the next one starts.
So a system doesn't water your whole yard at once. It works through it one zone at a time.
Why Not Just Run Everything at Once?
The main reason is water. Every home has a limited amount of water flow and pressure available to the sprinkler system. Each head uses a certain amount of water, and there's only so much to go around. If too many heads run at the same time, the pressure drops and the spray gets weak, misty, or short.
For example, on most new construction homes you can get around 15 gallons per minute (GPM) for each zone. An acreage on a well may only get around 10 GPM. With less water available, you can't put as many heads on each zone, so the same yard ends up needing more zones.
Splitting the yard into zones keeps each group of heads within what your water supply can deliver, so every head works the way it's designed to.
What Decides How Many Zones You Need
Available water flow and pressure. This sets how many heads can run together.
The size and shape of the yard. Bigger or more complicated yards need more zones to cover everything.
The type of heads. Spray heads and rotors put out water at different rates, so they're usually kept on separate zones. Mixing them means one area gets too much while the other gets too little.
Sun and shade. A sunny south-facing lawn dries out faster than a shaded north side and needs more water.
Slopes. Water runs off hills faster, so slopes often do better on their own zone with shorter, repeated run times.
What's being watered. Lawn, flower beds, shrubs, and trees all have different needs. Drip lines for beds are typically on their own zones.
More Zones Isn't Always Better, and Fewer Isn't Either
Too few zones can mean weak spray, uneven coverage, or areas with different needs getting the same schedule. Too many can add cost and complexity, and each zone adds to how long the whole cycle takes to run.
A good design finds the balance for your yard. It uses as many zones as it takes to water evenly and no more.
Why Zones Matter for Your Lawn
Zoning is what lets you give each part of your yard the amount of water it actually needs. If one side bakes in afternoon sun and another stays shaded, separate zones let you give each the right amount, instead of overwatering one to keep the other alive. It's also how you avoid soggy spots and dry spots on the same lawn.
How to Find Out How Many Zones You Have
Look at your controller. It will show a number for each zone, and the highest number is your total
Count the valves in your valve box. Each valve controls one zone
Run each zone manually for a minute and walk the yard to see which heads come on
Write down what each zone covers, such as "front lawn," "side yard," or "back beds"
A simple map taped near the controller makes it much easier to adjust the schedule or describe a problem when you call for service.
Can I Add a Zone Later?
Almost always, yes. If you're adding a flower bed, expanding the lawn, or changing the landscape, a new zone can usually be added. There are two things that decide how easy it is:
Room on the controller. If your controller (the clock) is already maxed out, it may need to be swapped for a larger one that supports more zones.
A spare wire to the valves. This is usually the bigger factor. The valves are wired back to the controller through a bundle of sprinkler wire. If there's an extra wire in that bundle for another zone, adding one is much simpler. If there isn't, a new wire has to be run and connected to the controller as well.
The available water on your system doesn't limit whether you can add a zone. It comes into play if you want to add more heads to an existing zone, because each zone can only support so many.
Questions to Ask When You're Getting a Quote
How many zones will my yard have, and why?
Are spray heads and rotors on separate zones?
Are sunny, shaded, and sloped areas being separated?
Will the controller have room for extra zones later?
Talk With Alternate Rain
We've been designing sprinkler systems across the Omaha metro area, including Elkhorn, Papillion, Bellevue, Gretna, Bennington, Waterloo, La Vista, Blair, and Valley, for over 40 years. If you'd like to know how your yard would be zoned, or you have questions about the zones you have now, contact us. You can also read about how we install underground sprinkler systems.