The Science of ET

We've had a lot of customers ask how our "smart" features work. Questions like: Where do the recommended watering times come from? Why did the Iro suggest those numbers? How does Water Budgeting know what my new watering times should be? The answer to all of those questions is the same: through the magic of ET.

ET and the Water Cycle

Evapotranspiration, or ET, is a measure of how much water a group of plants (like your lawn or trees) loses in a given period. It's basically the combination of how much water evaporates from the soil itself, and how much water the plant transpires, or "breathes out". (That's where the word comes from.)

ET is part of the water cycle, which describes how water falls to the ground as precipitation like rain or snow, is absorbed by plants and the soil itself and then returns to the clouds. Understanding the water cycle is important for climate scientists, meteorologists, and agricultural scientists, and lots of people spend their whole lives studying it. Fortunately, we're really just interested in how it works in one area: your yard!

ET and Your Yard

All of the science boils down to this: your yard gains moisture from precipitation, and loses moisture from ET. If you lose more than you gain, you get dry soil and brown foliage. That's what irrigation is for--but it's tricky. Irrigate too little, and you're just delaying your yard's demise. Irrigate too much, and you're wasting water, eroding your topsoil, and sending all kinds of junk into your storm drains (and thus our rivers and streams).

Figuring out just the right amount can be hard, and that's where ET comes in. A lot of smart people have researched how much ET occurs when you take all kinds of things into account: soil type, plant type, average temperatures, wind speed, humidity levels, latitude, average sun exposure, you name it. Figure out which equations to use, feed in the right variables, and you can decide exactly how much water your lawn needs in a given week. Know the watering rates of your sprinklers, and you can calculate just how long to water.

We Think Hard, So You Don't Have To

Fortunately, you don't have to be a climate scientist to figure it out. Our software uses your zone details, location, climate data, and weather to run the numbers and recommend the best watering schedule for your lawn. And, as conditions change, Water Budgeting changes your schedule to match. It's not perfect - there are a lot of different types of sprinklers out there, for example - but we're working every day to collect more data to make our system smarter. We're not going to be happy until everybody has a great yard, that never wastes a drop of water!

Designed and Made in Colorado

We have been building Rachio for the better part of 15 months now and have a set of driving values that are essential to our continued passion as a company and have helped guide the design of our first product.

We obviously have a strong focus on sustainability through the reduction of water waste in our own backyards. A little less obvious is our passion to heavily contribute to the state we call home.

It has been a goal for our team from the very start to design, manufacture and assemble our product right here in Colorado. And we are very proud to say that we have accomplished just that and have been accepted into the By Colorado state branding program.

From the very start, we designed Iro with water conscious, outdoor loving, land optimizing and beautifying, tech savvy Coloradans in mind. With their help, feedback and guidance we’ve created a product that we believe embodies these characteristics as an amazingly simple, smart sprinkler controller that will not only appeal to Coloradans, but to the much larger market as well.

We are grateful and lucky to have been able to partner with so many local companies to help us build everything from our messaging, to our apps, to our hardware, and soon, our packaging. 

Creating a physical product along with software hasn't been easy and there’s no way we could have done it without help from a few very special Colorado companies, none more important for us than Intertech Plastics.  We can’t thank the people of this company enough.

The resources we need to build amazing products are right here in our own backyard and we encourage everyone to find and use them. We’re proud to be a Colorado company and can’t wait to make Colorado proud of us.

60 Days with Iro

We installed our first hand-assembled Iro at my house in early May and I thought I’d share what we’ve learned over the last 60 days.

Water was Saved

Yes, Iro does help save a lot of water! I've been pretty conservative when it comes to watering my landscape over the past few years, so I'll admit I was quite surprised when I looked at my usage numbers year-over-year.

I saw a huge 8,000 gallon savings in May and another 6,000 gallons saved in June. Here in Denver that saved me a little over $50 in that two month span.

Accessibility is Empowering

A big reason for the major water savings is due to the accessibility of scheduling and system tweaking all from the palm of my hand.

Spring Maintenance

It was easy to perform an early spring tuneup because I was no longer running back and forth to the irrigation controller to turn zones on and off. I found it way easier to inspect and tweak nozzles because I could simply turn them on and off with my phone. It's funny how something that simple is so empowering.

"...a lot of times it's actually good to water when it rains."

Weather

We're in the learning stage of our smart scheduling algorithm, so we've been doing a lot of manual adjusting of watering schedules. I found myself watching weather patterns specific to my neighborhood and adjusting my schedule accordingly. Here's something really interesting we learned: a lot of times it's actually good to water when it rains. Let me clarify.

Here in Denver we often get a quick sprinkle or torrential downpour that lasts for just a few minutes. Because of our clay soils, most of the time very little of this rain water is absorbed by our landscape. Good watering practice here in Denver is to cycle soak. That is, if you're going to water a zone for 15 minutes, break those 15 minutes up into three separate 5 minute cycles.

So, taking this into account, we found that treating our quick rains as one of those 5 minute cycles and then watering shortly after proved to be productive. We were able to take advantage of the rain loosening the soil up and cut our water usage for that given watering day by a third.

Zone Specifics

I started really paying attention to zone specifics like shade and soil type. I realized just how much those two attributes of a zone can drastically impact the amount of water you'll want to use. We talked about what clay soil means for us and the benefit to cycle soak above. Shade is also huge.

I found that certain zones in my landscape have a good amount of shade and can go 10 days or so without watering and still be healthy. We validated that all zones shouldn't be treated the same and that if we have a way to easily adjust for zone specifics, we can still have really healthy landscapes while using a lot less water.

So there you have it, 60 days with Iro and 14,000 gallons saved, a finely tuned system and a new engagement with my landscape that has made this spring enlightening and a lot of fun.