Standard & Advanced Zone Settings - Sprinkler Controllers

Last Update: Apr 13 2026 12:24pm • Est. Read Time: 10 MIN

Summary

This article explains how to edit Advanced Zone settings and explains each setting in detail. Advanced Zone Settings are primarily used for Rachio's Flex Daily and Flex Monthly schedules. The Advanced Zone Settings help Rachio calculate the schedule duration and frequency with the various attributes informing how much water your plants need, how much water is being put down, and how that water is retained in the soil.

Contents:

1. Editing Zone Settings
2. Basic and Advanced Zone Settings Breakdown
3. Understanding Advanced Zone Settings

Editing Zone Settings

Standard Zone Settings
You may need to update your zone information when switching to a Flex schedule, making changes to your sprinkler system, or simply personalizing how each zone is set up in the app.

1. Tap the Zones tab at the bottom of the screen.
2. Select the Zone you want to adjust.
3. Tap Edit in the right-hand corner of the screen.
4. Choose the settings you’d like to edit.

Advanced Zone Settings
Initially, Rachio assigns default values accordingly based on the zone attributes you've selected. We recommend that only experienced Water Managers adjust the Advanced Zone Settings.

1. Click on the Zones tab at the bottom of the screen to view your zones.
2. Select the Zone you’d like to adjust.
3. Click Edit in the right-hand corner of the screen.
4. Scroll down to Advanced to access the Advanced Zone Settings.
5. Tap Done at the bottom of the page to save your edits.

If you make an adjustment and you're not happy with it, you can always use the "RESET TO DEFAULT" button at the bottom of the page, which will reset ALL of your Advanced Zone Settings to those based upon the original zone attributes of each zone.

Note

Impact of Changing Zone Settings:

• Fixed Schedules: Changing these settings will only affect watering duration if Seasonal Shift is enabled. If Seasonal Shift is disabled, fixed schedule durations remain unchanged.
• Flex Schedules: Updating zone settings will always impact both watering duration and watering frequency.

Basic and Advanced Zone Settings Breakdown

Zone Settings

Some zone settings directly translate to one or more advanced zone settings, and some do not:

• Vegetation Type: Root Depth + Crop Coefficient
  • Affects both watering duration and watering frequency
• Spray Head: Efficiency + Nozzle Inches Per Hour
  • Affects watering duration
• Soil Type: Available Water [Capacity] (AWC)
  • Affects both watering duration and watering frequency
• Exposure: No advanced settings correlation
  • More sun exposure increases the watering frequency
  • Less sun exposure reduces the watering frequency
• Slope: No advanced settings correlation
  • Increasing the slope extends the soak time
  • Decreasing the slope reduces soak time

Advanced Zone Settings

• Area:
  • Only used to perform water usage calculations; does not affect watering frequency or duration
• Available Water:
  • Increasing this setting extends watering duration and reduces watering frequency
  • Decreasing this setting reduces watering duration and increases watering frequency
• Root Depth:
  • Increasing this setting extends watering duration and reduces watering frequency
  • Decreasing this setting reduces watering duration and increases watering frequency
• Allowed Depletion:
  • Increasing this setting extends watering duration and reduces watering frequency
  • Decreasing this setting reduces watering duration and increases watering frequency
• Efficiency:
  • Increasing this setting reduces the watering duration
  • Decreasing this setting increases the watering duration
• Crop Coefficient:
  • Increasing this setting increases the watering frequency
  • Decreasing this setting reduces the watering frequency
• Nozzle Inches Per Hour:
  • Increasing this setting reduces the watering duration
  • Decreasing this setting extends the watering duration

Note

To learn how to optimize Flex schedules through these settings, click here.

Understanding Advanced Zone Settings

Area is the size of the chosen zone. Changing the area (square footage) of a zone simply improves the accuracy of the Rachio app's water usage calculator when the Usage Units in Account Settings is set to "Estimated Gallons" instead of "Time". Knowing the proper size of the zone, along with the precipitation rate (associated with the Spray Head type), allows the app to approximate how much water was used in a run.

Available Water (AW) or Available Water Capacity (AWC) is the range of available water that can be stored in soil and be available for growing crops. The AW of soil is related to texture and structure; the spongier the soil, the more water it can hold. Typical AW holding capacities represent the amount of water that can be held in an inch of soil; in short, how much water can be available for plants with the depth of the root zone is known.

Root Depth (RZ) is the soil depth from which a plant extracts most of its water needs. The RZ is equal to effective rooting depth and is expressed in inches within the Rachio software. To determine the depth of the RZ, a soil sample containing the roots must be taken. It is recommended to use a soil probe to minimize disturbance of the soil and to obtain a good quality sample. Once the core is removed from the probe, look for the small roots to determine the number of inches from the top of the core to the deepest root near the bottom of the core. This sampling process should be done in several locations throughout the test area to determine an average depth.

Allowed Depletion (AD) is the maximum amount of Plant Available Water (PAW) allowed to be removed (expressed as a percentage) from the soil before an irrigation refill occurs. PAW is the total amount of water held in the plant root zone based on Soil Type and Plant Root Depth. Increased surface evaporation (loss) of water and usually higher rates of transpiration are associated with frequent irrigation events; It is best to irrigate only when the root zone has reached the AD threshold.

• For most landscape purposes, 50% AD represents a reasonable overall value for the typical soils and plants used in landscapes. 50% AD is the Water Manager's choice to irrigate when the soil moisture level is half depleted.
• For sensitive, shallow-rooted plants (where little reserve water is available), or very heavy, compacted soils, a smaller depletion should be considered (i.e. 30-50%)
• For stress-tolerant plants, such as desert plants, deep root zones, or lighter soils, a larger depletion can be used (i.e. 50-70%)

AD represents a management decision to use the water that is most readily available to the plant. While plants can still extract water from the less available water reserves, the plant will begin to show signs of stress or wilt.

In short, AD is the quantity of water that is easily used by the plants from soil moisture without withdrawing all of the water prior to refilling the soil profile. Additionally, by allowing the soil to dry down, it draws air into the root zone. Roots use this air to breathe & grow; having the appropriate amount of water and air in the soil allows the microorganisms to flourish, enabling the plant (& soil) to be healthy.

Efficiency (DU), also referred to as Application Efficiency or Distribution Uniformity (DU), tells us how efficiently the water is being distributed by the sprinklers. The lower the DU, the higher the run time needs to be to deliver enough water to the area with the weakest coverage.

• DU is a factor used to adjust the run time to account for the non-uniform distribution of irrigation water
• DU is be measured by conducting a catch cup, or catch can audit

If the E/DU is below 0.40, then time and effort should be spent identifying what needs to be done to ensure the system is operating optimally. This may include recommendations for improving maintenance or to seek the services of a certified Water Manager to identify the factors that are causing such poor performance. When the uniformity is low, it is hard to justify the amount of additional water needed to minimize stressed areas and achieve an acceptable appearance. When additional minutes of run time become excessive, runoff potential increases, and it becomes more difficult to do proper maintenance if the sprinkler system is operating beyond its desired or designated water window.

• Factors that contribute to water waste (and poor DU):
  • Pressure. In irrigation, there are two kinds of pressure, static and dynamic. Static pressure is the pressure of non-flowing water at the point of connection. Dynamic pressure is the pressure at a sprinkler head when the system is on. Static pressure determines pipe sizing and the size of sprinkler zones, whereas dynamic pressure determines head performance. Both pressures are commonly misunderstood and can have a significant impact on the efficiency of a sprinkler system.
  • Different types of sprinklers are designed to operate at different dynamic pressures. Typically, spray head nozzles are designed to perform best at 30 psi, while rotor nozzles are designed to perform best at 45-65 psi. It is important to pay close attention to the nozzle pressure specification because certain dynamic pressures are required to obtain the desired coverage and radius of throw. Under-pressurized nozzles typically produce dry rings around the heads, leading to overwatering in an effort to compensate for poor coverage. Over-pressurized nozzles produce misting and small water droplets that are lost to wind and evaporation. Over-pressurized nozzles also use 20-40% more water than properly pressurized nozzles, resulting in excessive, unnecessary water use.
  • Head spacing. Head spacing refers to the distance between heads, ultimately dictating nozzle size. Typically, spray heads are used when spacing is in the 5 – 15-foot range; rotors are used for radii of 20 feet or more. All sprinkler types perform best when head-to-head coverage is achieved. Obviously, using 12’ nozzles on heads that are spaced 15’ apart is going to result in coverage issues. Again, it is critical to refer to the manufacturer’s specification to determine the correct nozzle size for the desired radius for the pressure available.
  • Nozzle selection. Nozzles for different sprinklers apply water at different rates. Spray nozzles typically apply water at 1.5” – 2.0” / hour; rotor nozzles are usually in the range of .5” - 1” / hour. The rate at which the nozzle applies the water is also a determining factor when scheduling the controller. A nozzle with a lower application rate, theoretically, will have to run longer in order to apply the desired amount of water.
  • Nozzle size can also significantly affect the hydraulics of a sprinkler system. Nozzles are not only rated for a radius of throw, but they are also rated for flow, referred to as gallons per minute (GPM) and or gallons per hour (GPH) for drip or micro-spray nozzles. A common mistake when visually evaluating rotor heads that are under pressurized, and not achieving head-to-head coverage, is to use a larger size nozzle that is rated for more distance. Under pressurization is more of a GPM issue than an actual pressure issue, i.e., too much water is flowing through the sprinklers than the supply can provide by increasing the nozzle size, the GPM is increased, exacerbating the problem. Decreasing the flow of a zone by using nozzles with lower GPM is the best way to resolve pressure issues if a booster pump is not an option.

Nozzle Inches Per Hour is a measurement of how much water your sprinklers are applying to your zone. This rate is expressed in inches per hour, so is directly comparable to natural rain and evapotranspiration. Rachio has set up your zone with a default rate based on manufacturers' averages for the type of sprinkler head you selected for the zone.

Static Crop Coefficient (CC) Crop coefficients are properties of plants used in predicting evapotranspiration (ET). The coefficient is the ratio of ET observed for the crop. If ET is our zone checkbook debit, the crop coefficient will offset ET slightly and not remove as much from our account. Increasing the crop coefficient increases watering frequency, and decreasing the crop coefficient decreases watering frequency.

Dynamic Crop Coefficient is Rachio’s latest upgrade to our irrigation scheduling software. Crop coefficient helps us predict how much water is lost through evaporation and transpiration (evapotranspiration). Each crop type in the Rachio app has a different crop coefficient value (different plants have different water needs). A plant with a higher crop coefficient needs more water, and a plant with a lower crop coefficient needs less water. The crop coefficient helps Rachio calculate how frequently the plant should be watered.

Up until this point, the value in our app has been static year-round and based on an average for that crop type. The reality is that a plant’s crop coefficient changes each month. The value increases during the plants’ growing season (typically, the hotter months), and decreases during the dormant season and colder months. The crop coefficient value can be different for the same crop type based on the region where the plant is growing.

Rachio’s Dynamic Crop Coefficient will change the crop coefficient value each month to provide you with higher accuracy in our watering frequency calculations. The value will be updated on the first day of every month.

Dynamic crop coefficient FAQ

How do I turn this feature on and off?

1. Go to the Zones at the bottom of the screen.
2. Select the Zone, and then go to Edit.
3. Scroll down to Advanced and toggle the lock icon next to Crop Coefficient.

What happens if I turn this feature off?
When you turn this feature (by selecting Static) off, the crop coefficient value will revert to whatever you last had it set to. If you don’t change this yourself, it will be set to the system default.

How does Rachio calculate crop coefficients for my garden crops?
The U.N. Food and Agriculture Organization (FAO) publishes comprehensive tables of reference ET and crop coefficients for dozens of common vegetable and cereal crops. For Rachio “vegetable garden” zones, we interpolate between average initial, peak, and end-season values from the FAO tables and set them to appropriate months for your growing season. Find FAO here.

I’m an experienced Rachio user, and I’ve dialed in my crop coefficients via trial and error. I turned on this feature, and the value is different. Which should I use?
Our dynamic crop coefficient system is a generalized solution designed to meet the needs of most yards, most of the time. If you’re a dedicated gardener, you know your yard better than us; keep using what you’ve discovered (And tell us what works for you! We love to hear how experienced users use our features; you can email support@rachio.com)

Is there an offset feature? I.e. I want to use your recommended value + 10%
We did not design an offset into the initial release of this feature. If you want to use the recommended value plus or minus some offset, activate the feature on the 1st of the month, note the recommended value, then turn the feature off and select the value you want. If you have any recommendations for improvement, please share this feature with us by emailing support@rachio.com or posting on the Rachio Community.

What climate zone am I in?
The exact way we define a controller’s local climate is proprietary, but it’s generally based on seasonal rainfall patterns, temperature patterns, and frost dates. We have distinct parameters for local climates at roughly a county level; for example, the western suburbs of Denver, Colorado have slightly different coefficients than the eastern suburbs, but watering schedules will be very similar.

Where can I find the 12-month coefficient curves for grass in my region?
The system we use to interpolate coefficient values where there is no published research is proprietary, but rest assured that we’ve combed available peer-reviewed research to find as much data as possible.

Rachio controllers in Mediterranean climates (mostly found in CA, OR, and WA) use coefficient values from a smoothed curve interpolated from a commonly cited research study performed in California in 1985 (Table 1, below)

Crop Coefficient table values from the Meyer 1985 study in California

Data published by the University of California, Division of Agriculture and Natural Resources. Find more here.

Source: Meyer et al. 1985. Irrigation of turfgrass below replacement of evapotranspiration as a means of water conservation: determining crop coefficient of turfgrasses, pp. 357-364 in: F. Lemaire (ed.) Proc. 5th Intl. Turfgrass Research Conf., Avignon, France, July 1985. INRA Publications, Versailles, France.

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