Ephemeral Gully Erosion

With continued rainfall on already saturated soils we are seeing a dramatic increase in the occurrence of ephemeral gullies across Northeast and East Central Iowa. 

Ephemeral gully erosion is the highly visible erosion that we often see after heavy rainfall in areas of concentrated water flow.  It differs from the sheet and rill erosion we measure using the RUSLE2 model.  Sheet and rill erosion describes the gradual process of detachment and displacement of soil that occurs over time along a slope.  Gully erosion events, in contrast, are often dramatic and result in the displacement of many tons of soil into ditches, waterways, and streams during a single rainfall event.

Several conservation practices can help minimize the occurrence of ephemeral gullies.  Grassed waterways are a commonly used practice to hold soil in place in areas of concentrated water flow. Contouring or changing the direction of rows to run across the slope rather than up and down hill, can also reduce ephemeral erosion.  Steeper slopes that require more than contouring can have terraces, contour buffer strip, or prairie strips installed.

No-till or strip-till systems can also reduce the occurrence and severity of ephemeral gully erosion by improving soil structure and water infiltration. These systems eliminate the loose, tilled soil that is susceptible to detachment. Cover crops are also effective at improving soil structure, increase infiltration and decrease soil detachment. Having growing cover on the ground helps to keep soil protected from harvest until the following spring.

Funding is currently available through an NRCS pilot project to address ephemeral gully erosion. Farmers and landowners in the Middle and Upper Cedar Watersheds can contact us today for a free conservation assessment. We will work with your local NRCS and SWCD offices to find the right practices and programs to fit your specific needs. 

Jeremy Sills