1. Start safely
Do not open energized controllers, pressure vessels or buried equipment. Stop for flooding, damaged piping, electrical hazards or a dry-running pump.
2. Separate pressure from flow
Static pressure is recorded with no intentional draw. Dynamic pressure is recorded at the same gauge location while a defined zone or test outlet is flowing. Flow is volume per time.
3. Run a bucket test
Use a known container, time the fill accurately and calculate litres per minute. Repeat at least three comparable trials; isolate unrelated demand only where it is safe and permitted.
4. Run a meter test
Record a stable start and end meter reading, the exact interval and the units. Subtract readings before converting; an end reading equal to or below the start is not a valid delivered-volume test.
5. Record dynamic pressure
Fit or use an appropriate gauge at a safe accessible point. Record gauge location, elevation, static reading, active zone, nozzle condition and dynamic reading together.
6. Compare conditions
Municipal supplies can vary by time and demand; pumps can react to cycling, water level and controls. Repeat observations under comparable conditions before concluding capacity.
7. Use the measured result
Enter the measured flow in the Available Water Flow Test Calculator, preserve a reserve, then check both zone flow and pressure margin.
8. Note uncertainty
Bucket shape, timing delay, other demand, gauge location, partly closed valves, filters and changing nozzle sets affect a field result. Record what changed rather than averaging unlike conditions.
Worked example
Three 10 L bucket trials taking 20, 25 and 30 seconds yield 30, 24 and 20 L/min: average 24.67 L/min with a 40.54% spread. Repeat before using it as zone capacity.
Sources
- USDA NRCS — Irrigation Guide, Chapter 6
- Oklahoma State University Extension — Managing Pressure in Home Irrigation
- U.S. EPA WaterSense — Sprinkler Spruce-Up