Explainer · the controller · free to read
The schedule
nobody set.
Most controllers in the Sacramento area are still running whatever the installer typed in on the day the lawn went down. Fifteen minutes, every zone, every day, is the one we find most. Here is what that is actually doing — and why the right number cannot be read off the box.
Three numbers decide a schedule
How fast the heads put water down. How fast the ground can take it. How much the plants use.
A run time is those three numbers reconciled. The first comes from the nozzle maker’s catalogue, which is why it matters that the parts on a zone match — a zone with three brands of nozzle on it has three different rates and no single right run time. The second comes from the soil, and it is the one nobody checks. The third changes every month.
None of them is on the controller. The controller only knows minutes.
Theory gives you a starting number. In practice we spec the components from one manufacturer where we can, so the rate is a known figure and not a guess; we test the soil; we look up the parcel in the USDA Web Soil Survey to see how the ground in that neighbourhood behaves; and then we watch the zone run and let what actually happens on the ground make the final call.
The numbers
Spray heads put water down ten times faster than clay can take it.
That is the whole problem with most Sacramento lawns in one line. A great deal of this area is clay or clay loam. Fixed spray nozzles are the cheapest head to install. Together they cannot work on any schedule, because after the first few minutes the ground is full and the rest runs to the gutter.
| What it is | Puts down / takes up | Where the number comes from |
|---|---|---|
| Fixed spray head (the pop-ups on most Sacramento lawns) | about 1.5 in/hr | The nozzle maker’s catalogue. Rain Bird and Hunter both publish it for every nozzle. |
| Rotary nozzle (MP Rotator and the like) | 0.4 in/hr | Hunter’s published rate — “the lowest in the industry.” |
| Drip | 0.2–1 in/hr | Emitter spacing and flow; the maker publishes it. |
| Clay soil can absorb | about 0.1–0.2 in/hr | Typical published intake rates by soil texture. Yours is what a soil test and the USDA Web Soil Survey say it is. |
| Loam can absorb | about 0.5 in/hr | Same. |
| Sand can absorb | 1 in/hr and up | Same. |
| A Sacramento lawn uses in July | about ¼ in/day | CIMIS reference evapotranspiration for the Sacramento Valley, scaled for turf. Less in spring and autumn. |
Fifteen minutes, every day · an illustration
What the usual schedule adds up to.
A six-zone spray system, eight heads a zone at 1.5 gallons a minute each, fifteen minutes a zone, every day. Those are assumptions, chosen to be ordinary; your system is what it is.
1,080 gallons
Every zone, every day. On clay, most of the last ten minutes of each zone is running off the lawn, not into it.
7,560 gallons
Applied as about 2.6 inches over the lawn. A July lawn here uses about 1.75. In April it uses well under one.
226,800 gallons · $370
303 CCF priced at $1.22 per CCF. On a tiered account the last units cost the most; on a flat-rate account this never appears on a bill at all.
Two or three days a week, not seven. Each zone’s minutes split into short cycles with a soak between them, so the ground catches up. Run times that change with the month — the controller’s seasonal adjust exists for this and is almost never touched. And on clay, the honest answer is often a nozzle change before a schedule change: a rotary nozzle at 0.4 inches an hour gives the ground a chance no schedule can.
You can do the seasonal adjust yourself — it is one dial or one menu item, and turning it down to 60% in September is the single most useful thing a homeowner can do to a controller. We will still set the whole thing if you would rather not.
What a System Check does about it
Every zone runs while somebody watches it — and the controller leaves set.
We identify the nozzles on each zone and their published rate, check the soil, look the parcel up in the Web Soil Survey, and watch each zone run to see where the water goes. Then the controller gets a schedule built from those numbers, written down, with the seasonal adjust explained so you can turn it yourself. Option 02 includes it; the schedule alone is part of every check.
Precipitation rates are the manufacturers’ published figures for their nozzles. Soil intake rates are typical published ranges by texture; your soil is what a test says it is. Water use is scaled from CIMIS reference evapotranspiration for the Sacramento Valley. The season example is an illustration with its assumptions stated; the gallons are arithmetic and the dollars are those gallons at $1.22 per CCF, from Sacramento Suburban Water District tier 1 (0–15 CCF), rates effective 1 January 2026.
Every provider on our map prices water differently, and four of them we have not verified. Treat the dollars as an order of magnitude and the gallons as the real number — the gallons do not change with your provider. If you are on an unmetered flat rate, a leak costs you nothing on the bill at all, which is exactly why it is allowed to run for years.
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