Grassed Waterway

What is it:

Grassed waterways are constructed graded channels that are seeded to grass or other suitable vegetation. The vegetation slows the water and the grassed waterway conveys the water to a stable outlet at a non-erosive velocity. The most common areas are in draws between hills, and other low lying areas on slopes where water concentrates as it runs off of a field.

How does it help:

Grass or permanent vegetation established in waterways protects the soil from concentrated flows. Grassed waterways significantly reduce gully erosion and improve runoff water quality resulting from concentrated surface flow.

Planning ahead:

Grassed waterways should be designed and installed where gully erosion is a problem. Constructing the grassed waterway at the right time of the year will aid in proper establishment of the vegetation and help to ensure its success. If you have an area of concern, contact the local Soil and Water Conservation District/NRCS office for planning and design assistance.

Management:

Proper maintenance will protect your investment in a grassed waterway. The following tips will help ensure longevity of the waterway:

  1. Lift implements out of the ground before crossing the waterway.
  2. Bring row crop patterns into the waterway nearly level, or use it as the turn area. Don't plant end rows along the side of the waterway, as they contribute to failure.
  3. Fertilize as needed.
  4. Inspect the area frequently for places needing reseeding and eroding areas. Repair minor rills or gullies by reshaping and reseeding.
  5. Maintain the width of the grass area when tilling and planting surrounding fields.
  6. Don't let herbicide spray continue into the waterway.
  7. Don't use the waterway as a road. Vehicle tire tracks can lead to the formation of a gully.
  8. Don't mow the grass until a good sod is established. Once it is established, the waterway should be mowed periodically and invasive species controlled. Check with local SWCD/NRCS office on allowable time to mow if cost share is received to install practice.
  9. Maintain outlets to prevent new gullies from forming at the outlet. This may include reshaping and reseeding the outlet, or repairing or replacing components of structural outlets.

Additional resources:

  • NRCS Standard 412