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Irrigatable Area

This calculator finds the land area that can be irrigated with a given flow of water. The minimum system capacity (supply) is the available water from the supply. The water needs is the peak crop water need during a specific time period. The available hours of operation per day is measured as the available hours for irrigation on a worst case day. The system efficiency is based on the irrigation efficiency and distribution uniformity.

Learn more about the units used on this page.

Irrigatable Area As Limited By Water Supply

Minimum System Capacity (Supply):
Water Needs:
Operation Hours Per Day:
System Efficiency:
Irrigated Area:


The Equation

This calulator uses this formula to determine the Irrigatable area.


= Irrigatable Area (sq. ft)

= Minimum system capacity, or supply (gpm)

= Water needs (in/day)

= Operation hours per day (hrs)

= System Efficiency (as a decimal)

Reference: Washington State University