Zone water needs and duration
Open a zone’s detail view to see its governing model, water need, planned minutes, and limiting factors.
From depth to time
At its simplest:
runtime in minutes = required gross depth in mm / application rate in mm/hour × 60
The gross depth accounts for the applicable capture efficiency. The final runtime also reflects configured adjustments, zone caps, restrictions, and scheduling capacity.
For example, 5 mm applied at 10 mm/hour needs 30 minutes before other limits. A wrong application rate produces a wrong duration even when the soil model is otherwise correct.
Measure the rate with catch cups where practical. A catalog head rate is a starting estimate.
What sets the required depth?
| Model | Basis |
|---|---|
| Soil | The zone’s reconstructed water need and refill plan |
| Weekly | Remaining target after credited rain and applied water, spread across eligible sessions |
| Explicit manual run | Requested duration, subject to the manual dispatch policy |
Check the model on the zone. Sessions per week affects weekly scheduling; it is not the soil model’s primary trigger.
Without a soil sensor
The deficit is modeled water missing from the root zone, not a measured moisture percentage. LocalSky replays recent weather and watering history:
deficit = previous deficit + plant water use - effective rain - retained irrigation
plant water use = reference ET × the plant's seasonal crop coefficient
retained irrigation = valve-open hours × application rate × retained fraction
The result stays between zero and the soil’s available storage. Soil texture and root depth set that storage; the plant’s allowed depletion sets the watering trigger. Uncertain starting conditions remain a range until the evidence resolves them. Forecast rain and the next permitted watering opportunity shape the refill.
Area does not multiply runtime. Application rate is already a water depth across the zone. Sun/shade is saved but does not currently apply a separate soil-demand adjustment. A sensor can supply moisture checks; the modeled deficit should still be read as an estimate.
A 10 mm/hour rotor with 70% retained water supplies only 7 mm to the roots in an hour. A 38 mm/hour spray with the same setting supplies 26.6 mm in an hour. A long capped run can therefore leave a rotor zone with a remaining deficit. Check actual application rate with catch cups and verify soil and plant settings before treating a modeled deficit as proof that the yard needs more water.
Why minutes can be capped
A requested refill may exceed the zone’s run limit, a restriction’s cap, or the available watering window. The displayed plan reflects the limit.
Before raising a cap, check application rate, soil, roots, supply recovery, and available time. A longer run can create runoff or exceed a well’s recovery capacity.
Cycle-and-soak divides valve-open time into segments and adds soak waits. Total elapsed time can therefore exceed the watering minutes.
Read uncertain values
A missing deficit is not zero water need. The soil reconstruction may lack enough evidence or retain a range of possible starting conditions.
A probe percentage is not automatically an absolute measurement of plant-available water. Without calibration, LocalSky should not present a precise future percentage curve.
The separate no-watering soil outlook illustrates drying without future irrigation; the progressive water plan includes projected watering and rain. They answer different questions.
Seasonal water budget
The engine’s seasonal adjustment scales the plan before the final limits. At 100%, it leaves that adjustment unchanged. Check the effective result after changing it; a cap can prevent an increase from producing longer watering.