Drainage Calculator by Acreage
Our drainage calculator was developed in partnership with the University of Minnesota Extension to assist you in the preliminary design and understanding of your drainage needs. We encourage you to contact your local design professional or contractor for more specific design guidance and criteria.
These calculations are based on the Manning’s Roughness ASAE EP 260.3 Plastic Tubing Drainage Chart and should be used for estimating purposes only. Consult a Water Table Management Professional for design criteria information.
NRCS Engineering Field Manual (Chapter 14) suggests the following general range of drainage coefficients:
|Drainage Coefficient (inches to be removed in 24 hours)|
|Soil Type||Field Crops||Truck Crops|
|Mineral||3/8″ to 1/2″||1/2″ to 3/4″|
|Organic||1/2″ to 3/4″||3/4″ to 1-1/2″|
(The Minnesota Drainage Guide suggests the lower end of the range.)
Your local NRCS office or state extension service can provide specific recommendations for the soils and crops in your particular area.