Frequently Asked Questions
What is irrigation flow rate?
Irrigation flow rate is the volume of water delivered per unit time, expressed in litres/second (L/s), cubic metres/hour (m³/h), gallons/minute (GPM), or acre-feet/day. It determines how quickly a field can be irrigated.
How many GPM does a 1-hectare field need?
It depends on crop water requirement and irrigation frequency. A general guideline is 5–10 mm/day of application, which for 1 ha equals 50–100 m³/day, or about 0.58–1.16 L/s (9.2–18.3 GPM).
What is an acre-foot?
An acre-foot is the volume of water that would cover 1 acre to a depth of 1 foot, equal to 1,233.48 m³ or 325,851 US gallons. It is widely used in US water rights and irrigation planning.
What is the difference between flow rate and application rate?
Flow rate (L/s) measures the volume delivered per second from a pump or canal. Application rate (mm/hr) measures how fast water is applied per unit area, linking flow rate to the area being irrigated.
How do I size a pump for irrigation?
Pump sizing requires knowing the required flow rate (Q) in L/s and the total dynamic head (TDH) in metres. Power (kW) = (Q × TDH) / (102 × efficiency). A typical drip system may need 2–5 L/s at 20–40 m head.