Reconciling meter reading vs Gen 2 consumption

Newbie here… I just installed a Gen 2 16-zone unit to control my 12-zone system and did a quick audit of the consumption. Currently, we have a Mon/Wed/Sat directive. Before and after the Wed watering, I captured the meter readings and compared the consumption: Rachio weighed in a 497 gals in 75 min; the meter weighed in at 1621gals during that same period.

Several years ago, I did another test on individual zones and I have the #gals/min for each of the 12 zones. There appear to be a number of knobs to turn within the setup to affect the Rachio calculated value. I see where I should change several zones “flat vs sloped”, but wouldn’t that decrease the watering duration and decrease both the calculated and the actual?

What is the best knob to turn at this time to get the Gen 2 and the water meter to read about the same?



Hey @hamletrl!

Welcome to the community! There are two settings that affect usage- zone size and nozzle precipitation rate. Since you know the gallons per min, we are already a step ahead. What are the gpm values for each zone? Also, what are the sizes of these zones (approximations are fine!) Final question- how many heads are there per zone? With all of these variables, we can really nail that usage value down.



@mckynzee is always right, here is a little more information.


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@franz and @mckynzee,

I appreciate the feedback… I did an audit of my 12-zone system yesterday and got a reasonably good count of the functioning heads, the square footage, Flow (gals/min) per zone, and back calculated the precipitation rate from the equation provided by @franz. Really high precipitation rates…

Now, I need to insert the appropriate numbers in the right places… need some guidance. Square footage is easy enough for me to figure out, but is the precipitation rate plugged into the “Available Water” field? Got another article for me?



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Precipitation rate goes into your Nozzles as in/hr – in your case, you will probably want to create your own custom nozzles with the rate that you were able to calculate. see

Available Water is determined by the type of soil that you have. See


I’m intending to do the same, compare meter to Rachio usage rates and adjust Rachio settings to more accurately reflect usage. I may be missing something, but I thought I read on a post here that the square footage is only used to allow the system to calculate the water consumption. If that’s so, wouldn’t the easiest way to “adjust” the system’s reported usage be to modify the square footage to match the meter usage?

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@franz, @mckynzee, and @Linn

Ok… Progress…
I’ve taken the individual zone consumption rates, square footage, and back calculated a precipitation rate for each zone. I’ve also created a custom nozzle for each zone and have entered the square footage and custom nozzle into the application.

General questions:

  1. Is there a place in the application where I can find an estimated consumption without having to recalculate each zone?
  2. I did not see where the application picked up these changes in the history. Some were rather significant. I generally keep a log to record changes (OK, I’m a retired engineer with a terminal case of OCD), but I’m looking for an easy way to track the changes.
  3. The consumption data in my system is bogus. Can you purge all the data prior to 23-April at 12:00 (noon)?

Thanks for the help.


I’ve dug around quite a bit in the app, and I haven’t seen this anywhere.

  1. I did not see where the application picked up these changes in the history. Some were rather significant. I generally keep a log to record changes (OK, I’m a retired engineer with a terminal case of OCD), but I’m looking for an easy way to track the changes.

I’m a retired IT person (also with a terminal case of OCD) and the only way I have found to keep track of my changes is to keep a spreadsheet, with a new dated tab with my changes to each zone highlighted. I would really love for Rachio to have some kind of history log of changes that we could see. And I would also love to see the Watering History log and Device Updates set up so that we could download them (a CSV file would be just fine) – I know that I’m not the only one keeping track of my watering history, and I think we all like to record that information and track it in different ways.

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I kind of agree with you, but when you look at the variables that go into how the application calculates consumption, I consider square footage as a more definative variable. You either have bushes/grass within specific boundaries or you don’t. However, considering the mish-mash of nozzles I have installed, I would view the precipitation rate as less discreet. I may choose to manipulate this variable vis-a-vis a custom nozzle.


I did spend some more time thinking about this and agree that modifying the precipitation rate would be the right way to correct the water consumption figures since it is also used in the calculations for amount of time to water. In my case we only have two types of nozzles, Rainbird HE-VAN for grass and misters for our perennial beds, so hopefully I might be able to get away with only two custom nozzles.

If I get a chance I’ll run a consumption test this afternoon - have to open the meter pit - and report back on what I find.


@davelr, I think if you take the initial meter reading and then run the system for one minute, stop it, and then take a final reading you have the gpm for that zone. Do this for each zone and you have the value needed for each independent zone. The square footage only comes into play if you use the Rachio predictive model to perform this calculation for you. Now, the issue that we have is that there is no place to put this discrete value and bypass the predictive model. If you plug in the discrete gpm into the model, you break the model since it will still use Area and a Constant(K) in the calculation to predict usage. What is needed is a second predictive model which would: take the discrete gpm value at Zero-Time, multiply it by Delta T (which is the run time duration for the zone), and give us the final usage on the zone. The sum of each zone would be the total usage for the cycle. If Rachio then allows a field to input our Water dept’s cost per gallon, we can then have a fairly close representation of our cost per run cycle. The benefit of doing this for Rachio is the community savings will be a closer prediction of community usage since it will be based on actual meter readings.

I already do most of the things you want. By zone. With high precision - until a change is made (and then have to reset) or a broken head occurs (accuracy affected until fixed). See , approximately last 3 charts - gallons by hour, day, month are illustrated…

No connections needed beyond at the controller itself. I do have to manually get a ‘gallons per minute’ reading, per zone, at the water meter, after any change to a zone in made.

Data logging as fast as once every 60 seconds per zone. Analyze spreadsheets of data to your heart’s content.

Best regards,


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@a012895 (Bill)
Hey! That’s impressive Bill, but besides being more complicated and expensive than I have time for, your reply doesn’t have much to do with the specifics of my original post.

Nevertheless, impressive.

I was replying to Linn

Must have clicked on the wrong Reply button. Sorry.

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