What do you recommend to prevent erosion in a ditch line or swale?

If you have high water flow on a slope in a ditch line or drainage swale, you can choose a round stone (river rock) or a crushed granite product. Product size is subjective and based on the volume of water and the steepness of the slope you are dealing with. For a lower degree of slope or lower volume of water, you can choose a smaller River Rock (1-3”) or smaller 2” clear crushed granite. For a higher degree of slope or higher volume of intermittent water, you can choose larger River Rock (4-6”) or larger 4” or 6” clear stone crushed granite.