Agriculture, Soil, Fertilizer & Farm Operations worked example

Irrigation Water Requirement at 61% irrigation system application efficiency: a worked example

Suppose irrigation system application efficiency falls to 61%. This page works the full calculation at that level so you can see exactly which result moves and by how much. Calculate irrigation water requirement from field acres, target irrigation depth, and application efficiency.

The inputs for this scenario

  • Irrigated field area: 80 acres (held at the documented default)
  • Net irrigation depth to apply: 0.75 inches (held at the documented default)
  • Irrigation system application efficiency: 61 % (the input this scenario stresses; the baseline uses 85)

Working through the calculation

  • The calculation starts from the formula this tool documents: Water required = irrigated acres x target depth / application efficiency.
  • Irrigation water required works out to 98.36 acre-inches at these inputs, and this is the headline figure for the scenario.
  • Net crop water target works out to 60 acre-inches at these inputs.
  • Irrigation loss allowance works out to 38.36 acre-inches at these inputs.
  • Application efficiency works out to 61 % at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where irrigation system application efficiency sits at 85% and the headline result is 70.59 acre-inches, this scenario comes in 39.34% above the baseline at 98.36 acre-inches.
  • It computes the gross acre-inches to pump, plus the net crop water target and the loss allowance, from acres, depth, and efficiency. When the numbers land here, the stressed input is the lever to work; the walkthrough above shows exactly how much each output recovers as it climbs back toward the baseline.

Results at a glance

  • Irrigation water required: 98.36 acre-inches (headline result)
  • Net crop water target: 60 acre-inches
  • Irrigation loss allowance: 38.36 acre-inches
  • Application efficiency: 61 %

Run it with your numbers

  • To rerun this with your own numbers, open the live Irrigation Water Requirement calculator, set irrigation system application efficiency to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.