Using Flume to monitor flow rate


Since it looks like Rachio/Flume are not interested in integration based on community and web search, I am looking for a way to integrate these in a more simple way. The issue perhaps you can help me solve is how to convert the inches per hour to gallons per hour. I would run my particular zone, look at how many gallons were used over a period of time and convert to GPH. I know its not exact but I find putting out tuna can method (actually I used orbit catch cups) not very accurate.

Any ideas?

You should learn how to use webhooks to get data from Rachio pushed to your rapberry pi or a server.
Should you need help with this, ask; otherwise all of the info you should need is here (link). If you don’t want to bother with port forwarding, you can use a http tunnel, such as localtunnel (link) to route data to your pi / local computer without port forwarding / DDNS.

This would send you a notifications with data about when a zone starts & when it ends. For the ending it also includes duration in seconds. You can either take a Flume reading at the start & another at the end, otherwise you could lookup history over the last timeframe outlined by duration. Lets assume you’ve gotten a start and end readings.

End reading - Start reading = Consumption
(optional, if your consumption is not in gallons): Convert Consumption to Gallons
Duration (from Rachio) / 3600 (seconds per hour) = x.yz (fraction of an hour that the zone has run).
(Consumption in Gallons) / (fraction of an hour) = Gallons / hour

You can even take continuous readings of your Flume data while the zone is running and calculate the duration that the zone has been active using an internal clock. This would allow you to detect and deactivate irrigation in case of an abnormal reading.

Should you be taking continuous readings, or have access to a high-resolution history data, than it would be a good idea to take a minimum reading you’ve read and estimate your GPH using that reading. Zone usage tends to be relatively stable, and any increase over min is likely someone else using the water in the house (better yet, schedule your irrigation while everyone is sleeping).

Good luck, we are here to help in case you run into issues.


I have Home Assistant running on a Pi with the Flume and Rachio integrations. I’m an IT guy so I get what you are saying here. I think with the HA integrations I don’t have to deal with opening up ports and webhooks because the info is in HA and I can create an automation with Python or use the Node red integration I use for everything.

Great – new project!


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The conversion from gallons to inches will also still be inexact, as it depends on having non-overlapping zones, and measuring the square footage the zone covers, which is rarely rectangular. Next, convert gallons to cubic inches, and square feet into square inches, dividing to get inches, and then factoring time into it.

I have overlapping zones, and overlapping zones don’t coincide, as zone 1 covers part of zone 2, and zone 2 overlaps with zone 3. This obviously causes problems in calculating inches per hour for any particular zone, unless the zone (with circular areas) is properly mapped. The system really needs some significant rework to be properly zoned and code compliant to avoid watering the sidewalks.