Just set up my Rachio irrigation system...flex question

Hello everyone! I love the idea of the Flex Schedule! Seems like it will work great with my PWS! I do however have a question…

-I’ll make up an example…If Zone 5 is supposed to get watered tomorrow but the weather forecast is calling for rain such that irrigating Zone 5 is postponed tomorrow but then it doesn’t rain, what happens? Does it just get watered the next day? I would think it should.

The irrigation systems I’m familiar with that use personal weather stations and evapotranspiration, calculates an irrigation requirement. Once that irrigation requirement reaches say 0.25 or 0.50 inches then the irrigation system will run. The irrigation requirement increases everyday with the daily evapotranspiration but any rainfall is subtracted from the irrigation requirement. So if the irrigation req is 0.20" and the evapo for that day is 0.10" but it rained 0.15" then the irrigation req would be 0.20" + 0.10" - 0.15 = 0.15". Since the irr req didn’t reach 0.25" the irrigation system didn’t run.

If the irrigation req was 0.30" and the system is supposed to water at 0.25" but the forecast calls for rain, it would skip irrigating. If it didn’t rain like it was supposed to the irrigation system run the next day since the irr req is still higher than 0.25". Does the Rachio work similarly in than if it doesn’t rain when predicted, the system will irrigate the next day.

Hope that makes sense! Boy I love this irrigation system!


You can read the docs on support.rachio.com to get better detail but what you have stated is conceptually the same. Rachio has their ip but you set the depletion amount in a ratio and it will attempt to fully rehydrate the soil (amount required is computed from zone attributes), if rain is forecast then it postpones a day to account for actual reported accumulation.

The critical point as I have inferred is the available water setting. Through my own reading, this is an attempt at definin the permanent wilt point of the root zone, if water recedes past this point, the plant can’t recover and rachio will run the next available day regardless. This protects from consistently bad weather predictions where rain is forecasted but does not materialize.

I love my flex schedules, they are the best thing since sliced bread, beer and women!


Your enthusiasm is contagious :sunny:

Thanks for being a customer, and welcome to the community!

@plainsane knows more about the system than I do, so I would trust whatever he says :wink:



@jmed999, Flex schedules will delay the watering event until ET justifies it’s needed. This takes place on a zone by zone basis.

Flex schedules do this. We use MAD (management allowed depletion) to determine when to trigger a watering event on a zone by zone basis. MAD is defaulted to 50%. For details on fine tuning your schedules, please refer to this support article.

I’d give this post (and embedded links) a review if you’d like to learn more about available water.

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@emil I finally have my system connect to the yard now :slight_smile: So its real grass and real water bills. I can see that there will be a watering event with the raindrop and an indication on the calendar. Is there anyplace in the app or on the web I can see exactly how long and how many gallons that watering event is planned to be?

Also, can you clarify if flex will delay watering based on a future (same day, next day) forecasted event?

If this is a flex schedule, just go into the schedule and look at the zone durations. They won’t deviate since that is the duration to fill your bucket. You can change the duration by adjusting the waterdrop when editing a flex schedule.

There is no current way to derive gallons from minutes.

If there is significant precipitation that the bucket (zone moisture level) won’t be depleted, flex will skip until the next day where it will re-calibrate and look at current weather data again.


This is based on forecasted events? Is there a low water and high water mark in the bucket?

These zone graphs show how we track ET per zone on a daily basis.


@brkaus, yep, in a nutshell this is the concept of MAD (management allowed depletion). We default to 50%, so your schedule will water each zone anytime the that zone’s bucket is half empty/full.

To learn more about MAD, I’d recommend giving this blog post a quick read.

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