How a center pivot waters a circle

A center pivot is a long sprinkler pipe held up by wheeled towers that slowly circles a fixed pivot point where the well water enters. The outer tower sets the pace and the inner towers keep the pipe straight. Because the same pump flow is spread over the whole circle, a slower lap puts down more water and a faster lap puts down less.

Controls

Labels

Animation speed

End tower speed

Set by the percent timer on the pivot panel.

System length (radius)

Pump flow

Step through it

The pivot pointWater from a well or pipeline enters at the fixed center. A swivel joint lets the whole pipe rotate while the supply line stays still.
Span pipe and trussesA long steel pipe, stiffened by trusses, carries water outward. Drop hoses hang down so sprinklers spray close to the crop and lose less to wind.
The end tower sets the paceThe outermost tower runs on a timer. Inner towers start and stop on their own to keep the pipe lined up behind it.
Faster lap, less waterThe pump flow is fixed, so speeding up the end tower spreads the same water over the circle in less time. Each pass applies a thinner layer.
Slower lap, deeper wateringSlow the end tower and the lap can take two days, putting down a deeper application in one pass.

The math of one lap

The end tower travels the circumference, 2 x pi x radius. Divide that by its speed and you get the time for one revolution.

During that time the pump delivers flow x time liters. Spread over the circle's area (pi x radius squared), liters per square meter is the same as millimeters of water. So depth = flow x time / area. This is the bookkeeping irrigation designers use, simplified here by ignoring evaporation and wind drift and treating the end gun area as part of the circle.

Try it: set the pump flow to 50 L/s and drag the end tower speed from 4 down to 1 m/min. The lap time stretches from about 10 hours to over 40, and the depth per pass climbs from under 4 mm to about 15 mm.

Why the outer sprinklers work harder

Each meter of pipe near the end sweeps a much bigger ring of field than a meter near the center. Designers fit bigger nozzles toward the outer end so every part of the circle gets about the same depth. Watching the outer ring is a good check on uniformity.

Where Avid uses this

Avid's VerdantaIQ precision agriculture AI uses this kind of water bookkeeping, and in a session co-presented at IBM TechXchange 2026 it showed a documented 58 percent water reduction.

Sources

Interpreting and Using Center Pivot Sprinkler Designs (MF3608)Kansas State University Research and Extension
Sustainable Water Management for Small Farmers with Center-Pivot Irrigation: A Hydraulic and Structural Design PerspectiveSustainability (MDPI, open access)
Irrigation Methods: A Quick LookUSGS Water Science School

How to cite this model

Avid Solutions International. (2026, November 11). How a center pivot waters a circle [Interactive 3D model]. Avid Field Lab. https://avidsolutionsintl.com/explore/center-pivot

Last updated November 11, 2026

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