Grain Operations: Flooding and stored grain

by Charles Hurburgh and Dan Loy
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grain field flood
Late summer and fall flooding events increase the possibility of stored grain being inundated with floodwater. With only a few exceptions, flood-soaked grain is not useable for feed or food.

It is considered adulterated and must be destroyed. Flooding affects both the stored grain and the storage structures. The best option, while not always possible, is to move the grain before the flood reaches the bin, but stop using underfloor conveyors and legs once the water starts entering the pits.

Grain and grain products

Flood-damaged grain is adulterated grain because of the potential for many contaminants to enter through the water. This grain should be destroyed, never blended. Contact local public health and sanitation officials for the best disposal process in your area. The recent Food Safety Modernization Act will probably increase public awareness of the problem.

Water coming up from tiles and pits is just as suspect because storm and sanitary sewers are usually compromised in floods. Even field tile water may contain animal waste products, high chemical levels and other contaminants.

Corn will stay at 30% moisture after the water drains off; soybeans about 25% moisture. The moisture won’t travel more than a foot above the floodline.

Good grain on top of flooded grain must be removed from the top or side, not down through the damaged grain. The reclaim conveyors and pits under bins are likely to contain flood water as well. Remove all the good grain before doing anything with the bad portion. Do not start aeration fans on flooded bins.

Mold toxins are likely in rewetted grain. Warm wet conditions are ideal for mold growth. Soaked grain will spoil within a day or two at high moisture and summer temperatures.

Moldy grain is a safety hazard. Use precaution and wear protective equipment when working with moldy grain. Assume that flood-soaked grain will be moldy by the time the water has receded enough to permit access to bins.

Take care not to track or mix mud or gravel from flooded grounds into good grain during salvage operations. These materials are potentially toxic for the same reasons as the floodwaters.

The FDA allows for reconditioning (washing and drying at high temperatures) in cases where the flood water did not remain long and it is known that the water did not contain contaminants. This situation would be rare, to know that floodwater was clean. In past flooding situations, the water was determined to be contaminated; expect that to be true in this case as well.


Grains swell when wet so bin damage is likely; more so with soybeans. Bolts can shear or holes can elongate. Look for signs such as stretched caulking seals, doors misaligned or similar structural problems.

Check bins with stirring devices carefully. The bin must be perfectly round for them to work correctly.

Bin foundations may shift, float or deteriorate from flooding. Inspect structures and foundations carefully, and have an engineering evaluation for larger bins.

Expect electric wiring, controls, motors and fans to be ruined. Do not energize wet components. Be sure the power is off and locked out before touching any electrical components of flooded systems.

Wood structures will be hard hit and may retain mold and contaminants.

Clean facilities and grounds completely. Then do a careful food safety inspection before returning facilities to operation. A third-party inspection is recommended. Maintain records of cleaning.


In the rare situations where the water was not contaminated, the grain may be reconditioned. If the grain is to be sold, reconditioning has to be done with the written consent of the FDA. For feed on site, producers have three alternatives.

• Dry the grain

• Feed it immediately to their livestock

• Ensile the grain for livestock feed.

Decisions need to be made quickly. The good grain should be removed immediately, again not down through the soaked grain. No flooded grain can be sold to any market without approval of the FDA, to document its exposure only to uncontaminated water, with subsequent reconditioning and intended use.

There is no problem, other than spoilage within a day or two, with using uncontaminated soaked corn as a livestock feed. Just replace the corn in the animals’ current diet with the wet corn. Remember to adjust amounts fed for moisture.

Wet, whole soybeans can be fed to cattle if the soybeans are limited to 10% to 12% of the ration’s dry matter. Soybeans substitute well for the protein in soybean meal, but they need to be fed with a vitamin-mineral-additive premix if substituted for a complete protein supplement.

It is not necessary to heat-treat the soybeans for cattle. Also, if adding whole soybeans to diets high in distillers’ grains, watch the total ration fat content. For hogs, raw soybeans can only be fed to mature sows. The soybeans need to be heat treated if fed to younger pigs.

The Hurricane Harvey situation in southern Texas in 2017 is not likely to create salvageable situations.