Calculating zone areas

post by Microfiche on May 21, 2025

Hi all, I am trying to set up the advanced area of the zones to enter the zone area.

In a few of our yard areas, there are 2 sprinkler zones covering a single area. For instance, we have a 73’ x 9’ boulevard with two parallel zones, one at the street, and one at the sidewalk. Each side has 8 x 10’ sprinklers, arranged in a square layout. (That is the original layout drawing - the 10Q sprinkler on the left by the sidewalk is no more.)

Is the area for each zone 4½’ x 73’?

post by JBTexas on May 21, 2025

When I have adjacent zones with overspray and same nozzles, I assume the common border splits the distance between the zones (as you have assumed). I’d say your measurement is reasonable.

post by rraisley on May 27, 2025

Just a couple notes concerning Area:

If Area is used within Rachio, it would just be to calculate the “calculated” gallons used when irrigating a zone. That’s might be available within Rachio, but offhand I’m not sure where. Maybe in calculating a water savings or something. If an incorrect area is input, nothing is changed as far as how much or when water is applied.

The way /I/ use area is to calculate an accurate average Nozzle flow in inches per hour. I measure water flow over a given length of time using my water meter, and then calculate from that an accurate Nozzle flow. This is often called Precipitation Rate (PR), even though we’re talking irrigation, not preciptation:

PR = (96.25 * Total GPM) / Area (ft²)

And GPM (Gallons per Minute) is Gallons of Water Measure / Minutes = Gallons / Minutes

So the whole formula is

PR = 96.25 * Gallons / Minutes / Area (ft²)

(Parentheses in the original formula are unnecessary).

So if you measure 65 gallons in 10 minutes and have an area of 1500 square feet:

PR = 96.25 * 65 / 10 / 600 = 1.04 Nozzle Inches per Hour

The Nozzle here is a misnomer in my opinion, as it gives the idea that that amount is produced by each nozzle (in which case it would be gallons per hour and number of nozzles), but it isn’t.

Hope this helps. Calculating Area can be important IMHO as long as it’s used correctly.

post by Microfiche on May 27, 2025

Yes - that is what I was looking for when I posted, I wanted to calculate weekly inches of irrigation on each zone now that I have a flow meter installed. I wasn’t sure what Rachio was using it for, but figured I may as well align with what they would use for calculations. I assume it would be more valuable in the Rachio system if we were using flex daily and didn’t have water restrictions only allowing 3 days of watering.

post by championc on Jun 10, 2025

You can use Flex Daily and still setup for the permitted days, which it will adhere to.

post by Microfiche on Jun 10, 2025

I had read that it really wasn’t recommended by Rachio. We were using it that way at the beginning, but were getting some weird adjustments, so decided to go midway and just use the monthly. See how we feel once we are more used to the setup.

post by tmcgahey on Jun 12, 2025

It isn’t always recommended when big restrictions are in place as the algorithm struggles to keep the “bucket” full, especially in warmer climates.

post by Microfiche on Jun 12, 2025

Yeah, we definitely qualify for warmer here in the summer!