Managing forecasting with reclaimed water availability

Folks, not sure if this has been addressed in other forum topics, but here is my issue. As I head into Spring and early Summer, my reclaimed water availability for my sprinkler system becomes very unreliable. This primarily because of very high demand, no rain fall and limited supply. Okay, we can get into time period (normally 4-8 weeks) were reclaimed water availability is very hard to predict. There are time windows were it should be on, but our county services just shuts it down, and you basically have to wait for the next watering window. Naturally this throws off the Rachio forecasting, it thinks it watered but my grass got nothing and I have to switch my Rachio over to a fixed program and enable watering everyday to make sure I get some water. This leads to other issues that I won’t go into now.

I’ve recently installed a wired flow meter on my reclaimed water supply but final hookup to Rachio is pending. Im not sure how the Rachio will react to watering with little to no flow. Probably I’ll get some error messages, not sure. Additionally, I’ve installed a pressure sensor. With this pressure sensor, I would like to inform the Rachio that it should not attempt irrigation if the water is off. I can do this through an API call from my Home Assistant or signal through hardware wiring connected to relay. I was thinking of just overriding the rain sensor input. For example, water is off, activate rain sensor and all programs stopped. However, maybe this will screw up forecasting for next watering window. Any ideas or feedback would be appreciated.

I do not know much about the flow meter or using a pressure sensor as I have neither yet. However, as you mentioned, using this through your rain sensor would mess up the forecasting as it would think it got watered through the “rain”. The best would likely be for a change to Rachio, if it does not already do this, to basically skip the schedule when there is little to no flow. Probably the next option would be for them to change to handle a pressure sensor, but I would think that would be more work depending on what is implemented with the flow. However, changes take longer than many would like with their backlog, etc. In the meantime, I would suggest doing it through Home Assistant or whatever you like to use to sense low/no flow and/or no pressure and skip that schedule. Others might have other ideas too.

@gnsantos - Interesting use case! It may take some experimenting to see Rachio will react to the various inputs. Here is my thinking and YMMV:

  1. Flow meters will tell Raciho how much water is flowing on a zone and once configured for each zone can tell you if there is a high flow (i.e. broken head or pipe) or low flow (i.e. clogged head). I can’t remember if the water table is updated by the water measured by the flow meter (which is what I think you want) or by the fixed precipitation rate of the zone.

  2. If the pressure switch on the reclaimed water line tells Rachio the rain sensor is active (either via API or direct connection) then Rachio won’t water and the water table won’t be updated for any irrigation, just rainfall. So Rachio should try and water the next day it is scheduled to water.

Is the default schedule a Flex Daily schedule? Any days blocked out that it can’t water on?

Hope this helps. I think you’re going to have to hook it up and watch what happens when there is no reclaimed water for Rachio to use.

Hello @DLane, does Rachio really just postpone the current watering? I thought it would count rain as watering.

Great responses thanks. Yes, I’m using a flex schedule, normally, so Rachio can use soil moisture to automatically skip a program time. To provide a little more detail, my reclaimed water is normally on from about 12 midnight till 5am. And then when they transfer water it will come back on at 8am till about 11:00am, seven days a week during our non-dry periods about 10 months a year. So basically two windows per day. During our dry period the first window can shutoff by 3am and second window may not occur at all. Obviously, scheduling for first window is the easiest, but there are times the first and second window are off. There is no warning, it’s completely unpredictable. Worst case, water may only come on twice a week for first window. With the pressure sensor, I basically want to skip, if water not available, my desire is that Rachio will attempt on next available water window. If I can use my pressure sensor to trip the rain sensor input on the Rachio, not because it’s raining, but to skip a program window and it doesn’t impact soil moisture, then it should give me the opportunity to enable a flex schedule for both windows and manage through this period more effectively without under or over watering. Of course if we get rain, and it’s picked up by nearby weather station then this just goes into the normal forecasting algorithm to compute soil moisture and program watering time is skipped, no problem.

@Thomas_Lerman - think about a rain sensor with a temperature sensor built in too - so freezing conditions. I believe Rachio will postpone the current watering. Looking at the formula that Rachio posted for calculating the water table, the adds were rain (via the weather service to determine amount) and irrigation (via time and precipitation rate on the zone).

@gnsantos - I’d say give it a try in hooking up the pressure switch to the Rachio as a rain sensor. Remember Rachio is designed for a normally closed rain sensor - so the pressure switch will need to open the circuit when there is no pressure/water.

It seems like how much it thinks it rains? Come to think of it, I do not know what it does if it the forecast indicates no rain, but the sensor indicates “rain”? Plus, it is really a rain “skip” or a rain “postpone”?

Okay, after some time, I’ve finally got a good working solution for this. However, it’s a bit long and technical, but here are the details nevertheless. Really the Rachio team should look to add a “add on” solution for customers that need to manage unreliable reclaimed irrigation water. Maybe, my case is rare in the global Rachio smart irrigation space.

To begin with, I added an Everydrop flow meter and connected this to my Rachio. When the reclaimed water was unexpectedly shut off and my regular watering schedule attempted to irrigate during this time, then I would get an email and a warning in the app for the zones run with a “Low Flow Detected” warning. However, surprisingly the Rachio software switches to a default estimate mode for water consumption, and my soil moisture goes up as if the zone is watered, when in fact it’s not, because my reclaimed water is shutoff. Seems like a bug, or maybe it’s intentional in the Rachio software for some reason that I can not think of. However, since I got the warning in the app, I knew my grass was not watered (due to reclaimed water not being available), but I have to manually zero out the soil moisture for the zones to get the app to attempt to water on my next scheduled watering window. So not really a good solution, too many manual steps.

My next phase was to step it up and add a pressure sensor to my reclaimed water line and feed the rain sensor input on my Rachio to dynamically disable watering when reclaimed water is not available. This pressure sensor interfaces with some custom electronics that enables/disables the rain sensor input on my Rachio. The custom electronics includes Arduino w/esp8266, LM393 voltage comparator, 5V relay for 24VAC, pressure transducer, 24VAC to 5v voltage supply converter, and Home Assistant for monitoring and overriding the rain sensor input to my Rachio. If the rain sensor is enable, Rachio will not water during the scheduled window. In this case, its not really about whether there is rain or not, I just need a way to dynamically skip watering for a scheduled watering event based on whether I have reclaimed water available. Rachio does not add anything to soil moisture based on rain sensor input, it exclusively uses weather data, and true rain observation data. In my case, I have a Tempest weather station linked to my Rachio for tracking actual weather and rain accumulation at my homestead.

Not sure this will help others, but it may provide some guidance to others with unreliable reclaimed water from a public source using Rachio and what it takes to manage through drought periods where reclaimed water can be restricted due to high demand or become unreliable due to repairs.