Question/Suggestion on drip irrigation control


#1

Apologies if this has been posted before, but after reading a number of posts I gather this issue hasn’t been addressed with Rachio yet.

It seems there are probably more than a few of us in arid parts of the country on xeroscape using drip systems. At the moment, I have two zones in my system with one untapped. My yard isn’t very big, and I have fewer than 20 plants that need watering…maybe increasing to 30 in the future but we’ll tap that other zone if we need to.

My system is currently set up to water each zone at it’s own interval, start time and duration - pretty basic and I don’t think I’ll have trouble setting this up with Rachio’s interface.

What would be great for those of us with xeroscaping is to be able to “set it and forget it,” but this looks to be incredibly cumbersome with the current algorithms - which seem like they work best for grassy yards with some known area, sprinklers that water a certain amount of that area, etc.

What I’m imagining is something like this: we know how much our drippers are dripping, we’ve bought specific heads for them and can intelligently put them at specific locations to water specific plants with very precise amounts - but we’ve got a number of them on a single zone. I want the software to be able to watch the weather and adjust. On average, let’s water X amount at X interval. Is it an incredibly hot summer? Change that to X+1 amount at 2X interval - the demand from the plants should still work out since we’ve got bigger plants on a higher flow rate and smaller plants or less water-dependent plants on a lower flow rate. Is it a cooler fall, with an unseasonable amount of rain reported? Shut it down. Is it a mild winter, with typical rainfall? Keep the status quo.

Is this beyond the capabilities of the programming or an unreasonable expectation? Maybe I just need some help sorting out how I’d do this under the current paradigm.

What it may fit best under is a new type of watering schedule - user defined. If the software can’t do it, perhaps we can do it on our own? Have something like watering schedules for “Normal,” or “Hot and Dry” or “Cool,” that you can toggle through and select based on conditions?

Appreciate your thoughts and your help!


#2

@njhaley I think the solution that you’re looking for already exists in the Flex Daily setup. Several of us on this forum are running it in Phoenix, and after getting things dialed in you’ll find that it’s quite intelligent, even for drip.

You need to first get your soil defined properly, and your vegetation type of course, including your root depth. Once you have that all set, you just need to define a custom flow rate for your drip setup. This post shows you how to go about that.

Let me know if your have questions.


#3

I’ll have a look at that, David, thanks!

I just got the system and will be installing it this weekend. Currently I’m working on the soil typing but it looks to be sandy loam or loamy sand :slight_smile:

Are there any good low-tech ways to ID root depth? We’ve got mostly Lantana, red yucca, a few agave and some cacti. All are well established and most have been present since the home was built about 15yrs ago.

Appreciate your help.


#4

No problem. The best way to determine your soil type without much work is using the Web Soil Survey. Take a look at the ‘SOIL’ part of this link, and follow its links.

If you want to play around with your own testing, do a search for ‘Mason Jar Test’ on this community. What state do you live in ?


#5

Appears to be a very well thought out write-up, David. I’ll give it a shot. Also looks like Rachio may be working on the problem so I’ll be patient.

I’ll spend some time this weekend working on the math and let you know how things come along. I also think I’ll need to go through and identify or replace all of the drippers - they’re cheap and easy to replace so I’ll make better time replacing them with new and known GPH drippers than trying to guess or measure what they actually are.

I’m in north Phoenix/Cave Creek. Problem I’ve seen already is IDing the best weather station nearby. Deer Valley airport is good but rain totals vary so much across town as I’m sure you know. There are WU units close by but they rarely have rain measure. Might be easiest just to manually input rain events.

More to come…


#6

May take a step back and think about it before I purchase new emitters as well.

How do you determine the ideal duration of watering? Seems like in the summer you’d want it watering overnight, maybe even in a short period of time in the pre-dawn morning?

For your 7.5g/shrub set up, maybe it’s better to have 2GPH emitters than 1GPH emitters? Or maybe, depending on soil type, the 1GPH emitter is best to prevent overflow…it irks me to see neighbors watering systems pouring into the streets :slight_smile:


#7

@njhaley, I’m sure you’ll enjoy hearing from @Modawg2k. He lives in your neck of the woods and has been battling the weather pattern issue you mention. He’s spent a lot of time looking at PWS and the Deer Valley Airport, if my memory serves me.


#8

Yeah, that 7.5 gal setup is on my list for the fall. I’d like to add additional 1/4" lines for the bigger plants. For that reason, I’d likely keep that at 1GPH. I know that @Modawg2k has a challenge with 2 GPH heads for the runoff reason that you mention.

I always start early-morning. Since I have a yard and garden that I want to have priority, my shrub zone sometimes has to wait until 6:30am or so. If it doesn’t have to wait it starts around 5am. I honestly don’t know if watering shrubs overnight would be a problem, other than at the start I’m guessing temps would be higher than they would at 5am, so you’d get more evaporation.

I rely heavily on the ‘Water Use It Wisely’ recommendations. It’s nice that we can use them to determine how many gallons to deliver. Just as useful is that once you have everything set up in Rachio on Flex Daily, you can also do sanity checks against the recommendations they give you for frequency of watering.


#9

Thanks for that. I’m thinking the most important rule for duration is to not produce runoff. Secondly, you wouldn’t want it too slow so that it evaporates before reaching the appropriate root depth…

There’s more to this than I imagined. And I came into this thinking an irrigation system would be no sweat - easier than having to water with a hose sprinkler; and certainly xeroscaping would be easier than having a lawn!

I’ll have a read, we’ll get this sorted out.


#10

All true, but you’re going the harder path not just to get it to work, but instead getting it optimized. That way you don’t have to be messing with the controller between seasons, and you’re watering less than everyone else in your neighborhood! As you know, setting up fixed schedules that overwater is a piece of cake. :wink:

You have the right attitude and a lot of support on these forums, so it should be fairly straightforward for you.


#11

Xeriscaping. For drip a rule of thumb is it takes about 22 to 30 minutes to apply .25 inch of water. I would set a custom sprinkler up and call it drip. The pretend inches per hour would be about .25 inch per hour. Then put in your plant type, soil type, sun exposure. Try this and see if this about right.


#12

Unless I’m reading you wrong, that doesn’t exactly take into account that on zone 1 I have 10 drips arising from my conduit: 6 that are 1gph, 2 that are 2gph, and 2 that are 0.5gph. Zone 2 is completely different with bubblers serving trees. How do each of those relate to 0.25in/hr?

For me it’s more intuitive to work through the math provided in David’s link above, I think.


#13

@njhaley I forgot the link. Here it is:

First set you Area of Interest. Use your address, and draw a rectangle using the AOI icon. After that the link above will guide you.


#14

I forgot to answer this. When you go through the Water Use It Wisely site it will give you a range of root depths for different vegetation types. You might need to use your judgement on where you lie in that range if you have varying levels of plant maturity and type. Keep in mind that setting deep roots tells the system to water longer and less frequently, so if you have less mature plants that might need more frequent watering you don’t necessarily want to pick the deepest estimated root depth in your zone.


#15

Welcome to the forum, @njhaley. You’ll find a helpful bunch of desert rats here.:wink: Xeriscape and drip systems and the unique characteristics of our desert adapted plants can be a bit mind-boggling at first, but once you get the controller set up, you may be surprised. I appreciated your comment about seeing water being wasted pouring into the streets.

@azdavidr has done his homework and his posts regarding drip irrigation are absolutely worth the read. @Modawg2k turned his lawn from one with a dead spot to beautiful green.

Since your landscape is well established you may find it requires little water. Desert plants have several adaptations that help them during prolonged droughts. Some have waxy leaves, some have no leaves at all and some drop their leaves when there is little water available.

Lantana, hesperaloe (red yucca) and succulents such as cacti and agave have fairly shallow root systems, but they do spread out to capture rain water when it’s available. A saguaro’s root system is not often more than 4 inches deep, but spreads out about as far as the cactus is tall.

Over-watering these plants may kill them, so flexible daily schedules are perfect for this situation. My xeriscaped front yard is well established and I don’t think that my hesperaloe even has an emitter any more.

Now if those waskly wabbits would stop munching on it!


#16

It’s important to identify soil type.

There’s quite a bit of research being done on drip irrigation. Soil wetting patterns are affected by soil density and application rate–generally the denser the soil, the more the water spreads laterally.

Increasing the application rate (as in 2 gph emitters) will increase the soil wetting pattern laterally. The studies show that reduced flow rate increases wetted soil depth and decreases the wetted width.


#17

I’m in anthem and having these same issues but loving the rachio so far. Thanks for the links.


#18

Thanks for everyone’s help so far. The soil type is most likely sandy loam based on a Mason jar test, but it doesn’t go much deeper that a foot before I hit the hard stuff.

I managed to get everything installed this morning in less than an hour, didn’t even have to run to home depot for supplies to finish the install!

I did visit this afternoon to pick up replacement drip nozzles so I’d know exactly how much was being emitted at each plant. We also picked up a bunch of new ornamentals for the front yard which will be incorporated into the small plant zone.

I know I’ll be able to get this sorted out, but I still think there are some pretty significant problems with the way the software and app work today. I’m a pretty smart person, so I can’t be the only one that doesn’t get this.

For example: why can you only put one emitter per zone? I can’t be the only one who has these things stacked up in series - either in the desert or anywhere really. Without doing a bunch of non-intuitive math, it’s a pain for the layperson to sort out easily. Even for an advanced lawn care expert this is non-intuitive… Instead I think the algorithms are something only a soil scientist or a turf manager could digest - not your everyday homeowner.

This brings up the more important point I think: how can you be certain how much water you’re using and therefore saving? We’ve got almost a dozen drips in our front yard - some 2gph, most 1gph, some 0.5gph. How can the software ever take all of those into account and accurately determine how much water was used without knowing each and every drip connected in series on the zone?

Again, I love the system, it was a breeze to install and I’d recommend it to anyone, but I think these missing pieces are a serious flaw in the app/user interface. Hopefully it’s something they address in a future overhaul…


#19

i set up a custom emitter nozzle myself for my drip then realized it thought it was pushing 200 gallons an hour. i’m in the same boat as you at this point.


#20

What was your emitter PR and about how many emitters do you figure that you have ?