Water distribution
Irrigation calculator.
Irrigation Runtime & Catch Can Uniformity Calculator
Compare a gross flow estimate with the water that actually lands in equal-area catch cans. Find uneven delivery before changing the whole watering schedule.
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How to use Irrigation calculator
- Enter total system flow, irrigated area and your chosen depth. One millimetre over one square metre equals one litre.
- Run a timed catch-can test using suitable equal-area containers and enter measured depths in row order.
- Compare gross runtime with catch-based runtime. Use the map to investigate low-delivery areas.
A worked example
A target of 10 mm over 20 m² is 200 litres. At a total flow of 10 L/min, gross runtime is 20 minutes. Catch-can observations can produce a different estimate because they describe collected water.
Assumptions and scope
Catch counts must be a multiple of four for the defined lower-quarter calculation. Four is an arithmetic minimum, not a reliable field sampling recommendation; the source recommends at least 24 cans for a lawn audit. Coverage, wind and positioning matter. The tool does not automatically increase the dose to compensate for poor uniformity.
Primary method or data reference ↗
Results use the entered values and the method described here. Keep units, sampling conditions and the source of the data with your interpretation.