Drip Zones & Irrigation Zones from Source Flow
Schedule well
When the field needs more flow than the source delivers, split it into zones: zones = ceil(system flow ÷ source flow). Enter the flows and the run hours per zone to get the number of zones and the total run hours.
Enter your drip system
Next: schedule the 4 zones to run back-to-back — the field needs 8 h of operation total, so check it fits inside your daily watering window and the source can sustain 12 m³/h.
Zones = ⌈demand ÷ source⌉; total run = zones × per-zone run.
Drip zone scheduling — key facts
- Number of zones
- ceil(system flow ÷ source flow)
- Total run hours
- zones × run hours per zone
- System flow
- all emitters at once
- Source flow
- well / pump capacity
- Why zones
- keep emitters at design pressure
- Round up
- no zone exceeds the source
- Zones run
- one after another
- Privacy
- Runs in your browser; nothing uploaded
Fit the field to the flow the source can give
A well, pump or canal turnout delivers only so much flow. If the whole field's emitters would draw more than that all at once, pressure collapses and watering turns uneven. The fix is to divide the field into zones, each small enough to fit within the source flow, and run them one after another. The number of zones is the system flow divided by the source flow, rounded up; multiply by the run hours each zone needs and you have the full irrigation cycle.
This tool gives the number of zones, the total run hours, the system flow and the source flow so you can build a sequence that protects pressure and finishes inside your daily window. Pair it with the Emitter Flow, Irrigation Set Volume and Water Hammer tools for a full irrigation plan.
Fit the source
Size zones so each stays within the source flow.
Hold the pressure
Avoid overloading the supply and starving emitters.
Plan the day
See the total run hours for the whole cycle.
Sequence the valves
Run zones one after another, cleanly.
Frequently Asked Questions
How is the number of zones calculated?+
By dividing the flow the whole field would need if irrigated at once by the flow the water source can actually supply, then rounding up. Zones = ceil(system flow ÷ source flow). Rounding up ensures the source is never asked for more than it can deliver — the field is split into enough blocks that each one fits within the available flow.
How is the total run time found?+
Each zone needs its own run hours to apply the target depth, and the zones run one after another because the source can only feed one at a time. So the total run hours = number of zones × run hours per zone. The tool multiplies the two to show how long the whole field takes to irrigate in a cycle.
Why split a drip system into zones?+
A water source — a well, pump, canal turnout or mains connection — can only deliver so much flow. If the whole field's emitters demand more than that, pressure collapses and watering becomes uneven. Splitting the field into zones that each fit the source flow keeps every emitter at its design pressure, so all plants get the right amount of water.
What is system flow versus source flow?+
System flow is the total flow the field would draw if every emitter ran at once — the sum of all emitter discharges. Source flow is what the well, pump or supply line can actually provide. When system flow exceeds source flow, you cannot run everything together, so the field is divided into zones sized to the source.
Why round the number of zones up?+
Because a partial zone still has to be watered. If the maths gives 3.2 zones, three zones would leave part of the field demanding more than the source can give, so you round up to 4. Rounding up guarantees every zone's demand stays at or below the source flow, protecting pressure and uniformity across the whole field.
Does more zones mean a longer irrigation day?+
Yes — zones run in sequence, so total run time grows with the number of zones. A field needing four zones at three hours each takes twelve hours to complete a cycle. If that exceeds the daily window, you either need a larger source, lower-flow emitters, or to accept a longer irrigation interval. The tool makes that trade-off visible.
How do I find run hours per zone?+
Run hours per zone is the depth you want to apply divided by the zone's application rate (the depth it applies per hour). The application rate comes from the emitter flow, spacing and wetted area. Once you know how long one zone needs to refill the root zone, enter it here and the tool scales it across all the zones.
Can zones be different sizes?+
They can, and in practice they often are — fields are divided along valves, slopes or crop blocks. This tool assumes evenly sized zones sized to the source flow, which is the usual design goal because equal zones share run time and pressure cleanly. If zones differ, size each to stay within the source flow and sum their individual run times for the total.
Are the figures precise?+
The zone count and total run hours are exact for the flows and run time you enter. Accuracy depends on knowing the true system and source flows and a sound run time per zone. Treat the result as the scheduling backbone, then verify the source delivers its rated flow and that each zone applies the intended depth in the field.