Looking upslope at a grass waterway between fields. Photo courtesy USDA NRCS
Grass waterways are a type of conservation buffer; they downhill grassed channels, generally broad and shallow, designed to prevent soil erosion while draining runoff water from adjacent cropland. As water travels down the waterway, the grass vegetation prevents erosion that would otherwise result from concentrated flows. Grass waterways also help prevent gully erosion in areas of concentrated flow.
Grass waterways are often used to drain water from areas of concentrated flow around constructed conservation practices such as terraces and runoff water diversions.
Grass waterways work best when erosion is controlled on the contributing upland drainage area; otherwise the waterway will become filled with sediment and cease to function properly. In addition to terraces and diversions (mentioned above), examples of upland erosion control practices include contour stripcropping, contour farming, water & sediment control basins, conservation tillage, conservation crop rotation and cover crops.
Gully/grade stabilization structures are often installed at grass waterway outlets to prevent gullies from forming there and progressing up the waterway.
Grass waterways often adjoin other in-field or edge-of-field conservation buffers such as contour buffer strips, grass filter strips and field borders.
Grass waterways of course involve grass planting and ongoing grassland management.
Guidance from USDA's Natural Resources Conservation Service
See contacts for specific programs that fund this practice in the side-by-side payment comparison or contact your local Soil and Water Conservation District