Drainage Calculators

The Drainage Calculators help users address common calculations for agricultural subsurface (tile) drainage design.


Pipe sizing

Drain spacing

  • Drain Spacing: Estimate the drain spacing needed based on drain depth and drainage coefficient
  • Drainage Coefficient: Estimate the drainage coefficient based on drain depth and spacing
  • Subirrigation Spacing: Estimate the drain spacing needed to use the system for subirrigation

Lift station design

  • Pump Size: Calculate the pumping rate required for a lift station
  • Sump Storage: Calculate the volume of storage needed for float control pumps in a lift station

Other drainage calculations



Contact the individuals listed below if you have questions or would like more information.

Christopher Hay
Assistant Professor & SDSU Extension Water Management Engineer

Gary Sands,
Professor & University of Minnesota Extension Engineer

These tools were developed collaboratively by SDSU Extension and University of Minnesota Extension. © 2015 South Dakota Board of Regents