Why Did My Flex Schedule Water Today after 0.5" of Rain?

I would appreciate it if you would look at my setup.

We had a big rain 2 days ago, almost 0.5". It’s properly noted in all of the zones.

But this evening zones 1, 5 and 8 watered for a total of 77 minutes. I can’t figure out why.

On the Water Schedule, if I click on Fri., the 11th, there is no water schedule shown. Nor is a Flex Schedule icon shown on this date.

If I click on Zone 1, then on Moisture Levels, then on More Detail, I see I started today with 0.53", no irrigation and and precipitation is shown, and ET is 0.10", leaving a balance of 0.43. Yet this zone watered. No water icon shows for today.

It’s exactly the same for Zone 5. And for Zone 8.

I know this isn’t a display problem because it really did irrigate - I have an energy monitoring system connected to the master valve terminal and it clearly showed the master valve to be ‘closed’ for a little more than 1.2 hrs.

I’m stumped. Why did the Iro decide to irrigate today? Why doesn’t it show any evidence of irrigation anywhere other than in Water History (and my separately interfaced system)?

Please help.

Many thanks!

Best regards,


I’ll forward this to [support@rachio.com] for review. If the weather station you are using is recording data properly and your moisture level is not being depleted, flex scheduling should not water, unless you have restricted days in place and we predict that until the next watering day we need to fill the bucket up.

Support will be able to review and explain the flex scheduling decisions.


I’m hoping to hear soon.

It rained 0.47" on 9/09.

At the moment, Flex Scheduling’s response is not understandable.

Depending on which screen you look at, for Zone 1, you’ll see 0.37" irrigation on 9/12 (soil moisture related screens) or you’ll see Last Watered on 9/11 in the My Yard screen.

I can’t figure out why Flex Scheduling scheduled any watering for a warm season grass one or two days after a 0.5" rain.

Please help. (This same problem occurred for Zones 5 and 8, same day and time).


Best regards,


@a0128958, sorry for the delayed reply.

Looking at your moisture graphs, Zone 1, 5, & 8 watered on Friday due to the limited allowed days available on the Flex schedule (Tuesdays and Fridays). The weather forecast (as of Friday) appears to have indicated that your soil moisture graphs would have fell below your allowed depletion tolerance by Tuesday (tomorrow) – as such, the Flex schedule watered on Friday.

Zone 2 didn’t water since it had received a manual watering earlier in the week.

As of 9/11, your zone’s soil moisture levels were the following:

Zone 1: 48%

Zone 2: 112%

Zone 5: 52%

Zone 8: 24%

Please note, Flex schedules work best with less restrictions and are not recommended for limited (less than 3 days/week) watering restrictions.

I believe this is a display issue as your watering time is 7p and we report in UTC time. If your watering times took place in the mornings, the watering icon on the moisture graph should align with the same day as the watering took place. I believe UTC changes to the next day for reporting purposes at 6p MST.

We did record a .47 in rainfall on 9/9, however it’s important to remember that warm season grasses have a 9 inch root zone depth. As such, it’s a big reservoir to fill. Have you performed a soil probe test to confirm the depth of your roots on a zone by zone basis? If not, I’d recommend doing so to fine tune your flex schedules (and the amount of water being applied to your lawn). For details, please refer to this support article: http://support.rachio.com/article/385-flex-schedule-tips

In short…

Moisture levels were forecasted to go below zero by Tuesday if no watering took place.

UTC time zone display

I hope this helps to explain the issues you noted. Let me know if you have any questions/concerns.

Best, Emil

1 Like

It does. Thank you.

I have eliminated my second flex schedule, that had certain zones assigned to it that could only water twice per week.

Now, all zones are in one flex schedule, with no limitations Starts at 12:05 AM 7 days per week - let 'er rip.

I’ll continue my learning journey from this point. Thank you.

Best regards,